Perl: Type coercion for the JSON conversion part of Perl (#12891)

* Perl: separate date and DateTime - Since the json values to be returned are different for date and DateTime, they are managed separately * Per: Enforcing Perl types to openAPI types Perl JSON values return different types depending on the context, so look at openapi's type and modify the type. * generate samples * generate docs * add perl test (json types)
2026-03-10 08:31:23 +00:00 · 2022-07-16 23:18:51 +09:00
parent e2b9f39b19
commit a9e63f4ce3
60 changed files with 2778 additions and 238 deletions
--- a/docs/generators/perl.md
+++ b/docs/generators/perl.md
@@ -41,7 +41,8 @@ These options may be applied as additional-properties (cli) or configOptions (pl

 <ul class="column-ul">
 <li>ARRAY</li>
-<li>DateTime</li>
+<li>DATE</li>
+<li>DATE_TIME</li>
 <li>HASH</li>
 <li>boolean</li>
 <li>double</li>
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/PerlClientCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/PerlClientCodegen.java
@@ -115,7 +115,8 @@ public class PerlClientCodegen extends DefaultCodegen implements CodegenConfig {
        languageSpecificPrimitives.add("double");
        languageSpecificPrimitives.add("string");
        languageSpecificPrimitives.add("boolean");
-        languageSpecificPrimitives.add("DateTime");
+        languageSpecificPrimitives.add("DATE");
+        languageSpecificPrimitives.add("DATE_TIME");
        languageSpecificPrimitives.add("ARRAY");
        languageSpecificPrimitives.add("HASH");
        languageSpecificPrimitives.add("object");
@@ -128,8 +129,8 @@ public class PerlClientCodegen extends DefaultCodegen implements CodegenConfig {
        typeMapping.put("number", "double");
        typeMapping.put("boolean", "boolean");
        typeMapping.put("string", "string");
-        typeMapping.put("date", "DateTime");
-        typeMapping.put("DateTime", "DateTime");
+        typeMapping.put("date", "DATE");
+        typeMapping.put("DateTime", "DATE_TIME");
        typeMapping.put("password", "string");
        typeMapping.put("array", "ARRAY");
        typeMapping.put("set", "ARRAY");
--- a/modules/openapi-generator/src/main/resources/perl/ApiClient.mustache
+++ b/modules/openapi-generator/src/main/resources/perl/ApiClient.mustache
@@ -112,7 +112,7 @@ sub call_api {
        $_request = GET($_url, %$header_params);
    }
    elsif ($method eq 'HEAD') {
-        $_request = HEAD($_url,%$header_params); 
+        $_request = HEAD($_url,%$header_params);
    }
    elsif ($method eq 'DELETE') { #TODO support form data
        $_request = DELETE($_url, %$header_params);
@@ -240,10 +240,16 @@ sub deserialize
            }
        }
        return \@_values;
-    } elsif ($class eq 'DateTime') {
+    } elsif (grep /^$class$/, ('DATE_TIME', 'DATE')) {
        return DateTime->from_epoch(epoch => str2time($data));
-    } elsif (grep /^$class$/, ('string', 'int', 'float', 'bool', 'object')) {
+    } elsif ($class eq 'string') {
+        return $data . q();
+    } elsif ($class eq 'object') {
        return $data;
+    } elsif (grep /^$class$/, ('int', 'float', 'double')) {
+        return $data + 0;
+    } elsif ($class eq 'bool') {
+        return !!$data;
    } else { # model
        my $_instance = use_module("{{moduleName}}::Object::$class")->new;
        if (ref $data eq "HASH") {
--- a/modules/openapi-generator/src/main/resources/perl/BaseObject.mustache
+++ b/modules/openapi-generator/src/main/resources/perl/BaseObject.mustache
@@ -55,7 +55,24 @@ sub TO_JSON {
    my $_data = {};
    foreach my $_key (keys %{$self->attribute_map}) {
        if (defined $self->{$_key}) {
-            $_data->{$self->attribute_map->{$_key}} = $self->{$_key};
+            my $_json_attribute = $self->attribute_map->{$_key};
+            my $_type = $self->openapi_types->{$_key};
+            my $_value = $self->{$_key};
+            if ($_type =~ /^array\[(.+)\]$/i) { # array
+                my $_subclass = $1;
+                $_data->{$_json_attribute} =  [ map { $self->_to_json_primitives($_subclass, $_) } @$_value ];
+            } elsif ($_type =~ /^hash\[string,(.+)\]$/i) { # hash
+                my $_subclass = $1;
+                my %_hash = ();
+                while (my($_key, $_element) = each %{$_value}) {
+                    $_hash{$_key} = $self->_to_json_primitives($_subclass, $_element);
+                }
+                $_data->{$_json_attribute} = \%_hash;
+            } elsif ( grep( /^$_type$/, ('int', 'double', 'string', 'boolean', 'DATE', 'DATE_TIME'))) {
+                $_data->{$_json_attribute} = $self->_to_json_primitives($_type, $_value);
+            } else {
+                $_data->{$_json_attribute} = $_value;
+            }
        }
    }
    {{#allParents}}
@@ -67,6 +84,36 @@ sub TO_JSON {
    return $_data;
 }

+# to_json non-array data
+sub _to_json_primitives {
+    my ($self, $type, $data) = @_;
+    if ( grep( /^$type$/, ('int', 'double'))) {
+        # https://metacpan.org/pod/JSON#simple-scalars
+        # numify it, ensuring it will be dumped as a number
+        return $data + 0;
+    } elsif ($type eq 'string') {
+        # https://metacpan.org/pod/JSON#simple-scalars
+        # stringified
+        return $data . q();
+    } elsif ($type eq 'boolean') {
+        # https://metacpan.org/pod/JSON#JSON::true,-JSON::false,-JSON::null
+        return $data ? \1 : \0;
+    } elsif ($type eq 'DATE') {
+        if (ref($data) eq 'DateTime') {
+            # https://metacpan.org/pod/DateTime#$dt-%3Eymd($optional_separator),-$dt-%3Emdy(...),-$dt-%3Edmy(...)
+            return $data->ymd;
+        }
+        return $data .q();
+    } elsif ($type eq 'DATE_TIME') {
+        # the date-time notation as defined by RFC 3339, section 5.6, for example, 2017-07-21T17:32:28Z
+        if (ref($data) eq 'DateTime') {
+            # https://metacpan.org/pod/DateTime#$dt-%3Erfc3339
+            return $data->rfc3339;
+        }
+        return $data .q();
+    }
+}
+
 # from Perl hashref
 sub from_hash {
    my ($self, $hash) = @_;
@@ -108,10 +155,14 @@ sub _deserialize {
    my ($self, $type, $data) = @_;
    $log->debugf("deserializing %s with %s",Dumper($data), $type);

-    if ($type eq 'DateTime') {
+    if (grep( /^$type$/ , ('DATE_TIME', 'DATE'))) {
        return DateTime->from_epoch(epoch => str2time($data));
-    } elsif ( grep( /^$type$/, ('int', 'double', 'string', 'boolean'))) {
-        return $data;
+    } elsif ( grep( /^$type$/, ('int', 'double'))) {
+        return $data + 0;
+    } elsif ($type eq 'string') {
+        return $data . q();
+    } elsif ($type eq 'boolean') {
+        return !!$data;
    } else { # hash(model)
        my $_instance = eval "{{moduleName}}::Object::$type->new()";
        return $_instance->from_hash($data);
--- a/samples/client/petstore/perl/docs/FakeApi.md
+++ b/samples/client/petstore/perl/docs/FakeApi.md
@@ -558,8 +558,8 @@ my $int64 = 789; # int | None
 my $float = 3.4; # double | None
 my $string = "string_example"; # string | None
 my $binary = "/path/to/file"; # string | None
-my $date = DateTime->from_epoch(epoch => str2time('null')); # DateTime | None
-my $date_time = DateTime->from_epoch(epoch => str2time('null')); # DateTime | None
+my $date = DateTime->from_epoch(epoch => str2time('null')); # DATE | None
+my $date_time = DateTime->from_epoch(epoch => str2time('null')); # DATE_TIME | None
 my $password = "password_example"; # string | None
 my $callback = "callback_example"; # string | None

@@ -585,8 +585,8 @@ Name | Type | Description  | Notes
 **float** | **double**| None | [optional] 
 **string** | **string**| None | [optional] 
 **binary** | **string****string**| None | [optional] 
- **date** | **DateTime**| None | [optional] 
- **date_time** | **DateTime**| None | [optional] 
+ **date** | **DATE**| None | [optional] 
+ **date_time** | **DATE_TIME**| None | [optional] 
 **password** | **string**| None | [optional] 
 **callback** | **string**| None | [optional] 

--- a/samples/client/petstore/perl/docs/FormatTest.md
+++ b/samples/client/petstore/perl/docs/FormatTest.md
@@ -18,8 +18,8 @@ Name | Type | Description | Notes
 **string** | **string** |  | [optional] 
 **byte** | **string** |  | 
 **binary** | **string** |  | [optional] 
-**date** | **DateTime** |  | 
-**date_time** | **DateTime** |  | [optional] 
+**date** | **DATE** |  | 
+**date_time** | **DATE_TIME** |  | [optional] 
 **uuid** | **string** |  | [optional] 
 **password** | **string** |  | 
 **pattern_with_digits** | **string** | A string that is a 10 digit number. Can have leading zeros. | [optional] 
--- a/samples/client/petstore/perl/docs/MixedPropertiesAndAdditionalPropertiesClass.md
+++ b/samples/client/petstore/perl/docs/MixedPropertiesAndAdditionalPropertiesClass.md
@@ -9,7 +9,7 @@ use WWW::OpenAPIClient::Object::MixedPropertiesAndAdditionalPropertiesClass;
 Name | Type | Description | Notes
 ------------ | ------------- | ------------- | -------------
 **uuid** | **string** |  | [optional] 
-**date_time** | **DateTime** |  | [optional] 
+**date_time** | **DATE_TIME** |  | [optional] 
 **map** | [**HASH[string,Animal]**](Animal.md) |  | [optional] 

 [[Back to Model list]](../README.md#documentation-for-models) [[Back to API list]](../README.md#documentation-for-api-endpoints) [[Back to README]](../README.md)
--- a/samples/client/petstore/perl/docs/NullableClass.md
+++ b/samples/client/petstore/perl/docs/NullableClass.md
@@ -12,8 +12,8 @@ Name | Type | Description | Notes
 **number_prop** | **double** |  | [optional] 
 **boolean_prop** | **boolean** |  | [optional] 
 **string_prop** | **string** |  | [optional] 
-**date_prop** | **DateTime** |  | [optional] 
-**datetime_prop** | **DateTime** |  | [optional] 
+**date_prop** | **DATE** |  | [optional] 
+**datetime_prop** | **DATE_TIME** |  | [optional] 
 **array_nullable_prop** | **ARRAY[object]** |  | [optional] 
 **array_and_items_nullable_prop** | **ARRAY[object]** |  | [optional] 
 **array_items_nullable** | **ARRAY[object]** |  | [optional] 
--- a/samples/client/petstore/perl/docs/Order.md
+++ b/samples/client/petstore/perl/docs/Order.md
@@ -11,7 +11,7 @@ Name | Type | Description | Notes
 **id** | **int** |  | [optional] 
 **pet_id** | **int** |  | [optional] 
 **quantity** | **int** |  | [optional] 
-**ship_date** | **DateTime** |  | [optional] 
+**ship_date** | **DATE_TIME** |  | [optional] 
 **status** | **string** | Order Status | [optional] 
 **complete** | **boolean** |  | [optional] [default to false]

--- a/samples/client/petstore/perl/lib/WWW/OpenAPIClient/ApiClient.pm
+++ b/samples/client/petstore/perl/lib/WWW/OpenAPIClient/ApiClient.pm
@@ -125,7 +125,7 @@ sub call_api {
        $_request = GET($_url, %$header_params);
    }
    elsif ($method eq 'HEAD') {
-        $_request = HEAD($_url,%$header_params); 
+        $_request = HEAD($_url,%$header_params);
    }
    elsif ($method eq 'DELETE') { #TODO support form data
        $_request = DELETE($_url, %$header_params);
@@ -253,10 +253,16 @@ sub deserialize
            }
        }
        return \@_values;
-    } elsif ($class eq 'DateTime') {
+    } elsif (grep /^$class$/, ('DATE_TIME', 'DATE')) {
        return DateTime->from_epoch(epoch => str2time($data));
-    } elsif (grep /^$class$/, ('string', 'int', 'float', 'bool', 'object')) {
+    } elsif ($class eq 'string') {
+        return $data . q();
+    } elsif ($class eq 'object') {
        return $data;
+    } elsif (grep /^$class$/, ('int', 'float', 'double')) {
+        return $data + 0;
+    } elsif ($class eq 'bool') {
+        return !!$data;
    } else { # model
        my $_instance = use_module("WWW::OpenAPIClient::Object::$class")->new;
        if (ref $data eq "HASH") {
--- a/samples/client/petstore/perl/lib/WWW/OpenAPIClient/FakeApi.pm
+++ b/samples/client/petstore/perl/lib/WWW/OpenAPIClient/FakeApi.pm
@@ -759,8 +759,8 @@ sub test_client_model {
 # @param double $float None (optional)
 # @param string $string None (optional)
 # @param string $binary None (optional)
-# @param DateTime $date None (optional)
-# @param DateTime $date_time None (optional)
+# @param DATE $date None (optional)
+# @param DATE_TIME $date_time None (optional)
 # @param string $password None (optional)
 # @param string $callback None (optional)
 {
@@ -816,12 +816,12 @@ sub test_client_model {
        required => '0',
    },
    'date' => {
-        data_type => 'DateTime',
+        data_type => 'DATE',
        description => 'None',
        required => '0',
    },
    'date_time' => {
-        data_type => 'DateTime',
+        data_type => 'DATE_TIME',
        description => 'None',
        required => '0',
    },
--- a/samples/client/petstore/perl/lib/WWW/OpenAPIClient/Object/AdditionalPropertiesClass.pm
+++ b/samples/client/petstore/perl/lib/WWW/OpenAPIClient/Object/AdditionalPropertiesClass.pm
@@ -100,13 +100,60 @@ sub TO_JSON {
    my $_data = {};
    foreach my $_key (keys %{$self->attribute_map}) {
        if (defined $self->{$_key}) {
-            $_data->{$self->attribute_map->{$_key}} = $self->{$_key};
+            my $_json_attribute = $self->attribute_map->{$_key};
+            my $_type = $self->openapi_types->{$_key};
+            my $_value = $self->{$_key};
+            if ($_type =~ /^array\[(.+)\]$/i) { # array
+                my $_subclass = $1;
+                $_data->{$_json_attribute} =  [ map { $self->_to_json_primitives($_subclass, $_) } @$_value ];
+            } elsif ($_type =~ /^hash\[string,(.+)\]$/i) { # hash
+                my $_subclass = $1;
+                my %_hash = ();
+                while (my($_key, $_element) = each %{$_value}) {
+                    $_hash{$_key} = $self->_to_json_primitives($_subclass, $_element);
+                }
+                $_data->{$_json_attribute} = \%_hash;
+            } elsif ( grep( /^$_type$/, ('int', 'double', 'string', 'boolean', 'DATE', 'DATE_TIME'))) {
+                $_data->{$_json_attribute} = $self->_to_json_primitives($_type, $_value);
+            } else {
+                $_data->{$_json_attribute} = $_value;
+            }
        }
    }

    return $_data;
 }

+# to_json non-array data
+sub _to_json_primitives {
+    my ($self, $type, $data) = @_;
+    if ( grep( /^$type$/, ('int', 'double'))) {
+        # https://metacpan.org/pod/JSON#simple-scalars
+        # numify it, ensuring it will be dumped as a number
+        return $data + 0;
+    } elsif ($type eq 'string') {
+        # https://metacpan.org/pod/JSON#simple-scalars
+        # stringified
+        return $data . q();
+    } elsif ($type eq 'boolean') {
+        # https://metacpan.org/pod/JSON#JSON::true,-JSON::false,-JSON::null
+        return $data ? \1 : \0;
+    } elsif ($type eq 'DATE') {
+        if (ref($data) eq 'DateTime') {
+            # https://metacpan.org/pod/DateTime#$dt-%3Eymd($optional_separator),-$dt-%3Emdy(...),-$dt-%3Edmy(...)
+            return $data->ymd;
+        }
+        return $data .q();
+    } elsif ($type eq 'DATE_TIME') {
+        # the date-time notation as defined by RFC 3339, section 5.6, for example, 2017-07-21T17:32:28Z
+        if (ref($data) eq 'DateTime') {
+            # https://metacpan.org/pod/DateTime#$dt-%3Erfc3339
+            return $data->rfc3339;
+        }
+        return $data .q();
+    }
+}
+
 # from Perl hashref
 sub from_hash {
    my ($self, $hash) = @_;
@@ -143,10 +190,14 @@ sub _deserialize {
    my ($self, $type, $data) = @_;
    $log->debugf("deserializing %s with %s",Dumper($data), $type);

-    if ($type eq 'DateTime') {
+    if (grep( /^$type$/ , ('DATE_TIME', 'DATE'))) {
        return DateTime->from_epoch(epoch => str2time($data));
-    } elsif ( grep( /^$type$/, ('int', 'double', 'string', 'boolean'))) {
-        return $data;
+    } elsif ( grep( /^$type$/, ('int', 'double'))) {
+        return $data + 0;
+    } elsif ($type eq 'string') {
+        return $data . q();
+    } elsif ($type eq 'boolean') {
+        return !!$data;
    } else { # hash(model)
        my $_instance = eval "WWW::OpenAPIClient::Object::$type->new()";
        return $_instance->from_hash($data);
--- a/samples/client/petstore/perl/lib/WWW/OpenAPIClient/Object/AllOfWithSingleRef.pm
+++ b/samples/client/petstore/perl/lib/WWW/OpenAPIClient/Object/AllOfWithSingleRef.pm
@@ -101,13 +101,60 @@ sub TO_JSON {
    my $_data = {};
    foreach my $_key (keys %{$self->attribute_map}) {
        if (defined $self->{$_key}) {
-            $_data->{$self->attribute_map->{$_key}} = $self->{$_key};
+            my $_json_attribute = $self->attribute_map->{$_key};
+            my $_type = $self->openapi_types->{$_key};
+            my $_value = $self->{$_key};
+            if ($_type =~ /^array\[(.+)\]$/i) { # array
+                my $_subclass = $1;
+                $_data->{$_json_attribute} =  [ map { $self->_to_json_primitives($_subclass, $_) } @$_value ];
+            } elsif ($_type =~ /^hash\[string,(.+)\]$/i) { # hash
+                my $_subclass = $1;
+                my %_hash = ();
+                while (my($_key, $_element) = each %{$_value}) {
+                    $_hash{$_key} = $self->_to_json_primitives($_subclass, $_element);
+                }
+                $_data->{$_json_attribute} = \%_hash;
+            } elsif ( grep( /^$_type$/, ('int', 'double', 'string', 'boolean', 'DATE', 'DATE_TIME'))) {
+                $_data->{$_json_attribute} = $self->_to_json_primitives($_type, $_value);
+            } else {
+                $_data->{$_json_attribute} = $_value;
+            }
        }
    }

    return $_data;
 }

+# to_json non-array data
+sub _to_json_primitives {
+    my ($self, $type, $data) = @_;
+    if ( grep( /^$type$/, ('int', 'double'))) {
+        # https://metacpan.org/pod/JSON#simple-scalars
+        # numify it, ensuring it will be dumped as a number
+        return $data + 0;
+    } elsif ($type eq 'string') {
+        # https://metacpan.org/pod/JSON#simple-scalars
+        # stringified
+        return $data . q();
+    } elsif ($type eq 'boolean') {
+        # https://metacpan.org/pod/JSON#JSON::true,-JSON::false,-JSON::null
+        return $data ? \1 : \0;
+    } elsif ($type eq 'DATE') {
+        if (ref($data) eq 'DateTime') {
+            # https://metacpan.org/pod/DateTime#$dt-%3Eymd($optional_separator),-$dt-%3Emdy(...),-$dt-%3Edmy(...)
+            return $data->ymd;
+        }
+        return $data .q();
+    } elsif ($type eq 'DATE_TIME') {
+        # the date-time notation as defined by RFC 3339, section 5.6, for example, 2017-07-21T17:32:28Z
+        if (ref($data) eq 'DateTime') {
+            # https://metacpan.org/pod/DateTime#$dt-%3Erfc3339
+            return $data->rfc3339;
+        }
+        return $data .q();
+    }
+}
+
 # from Perl hashref
 sub from_hash {
    my ($self, $hash) = @_;
@@ -144,10 +191,14 @@ sub _deserialize {
    my ($self, $type, $data) = @_;
    $log->debugf("deserializing %s with %s",Dumper($data), $type);

-    if ($type eq 'DateTime') {
+    if (grep( /^$type$/ , ('DATE_TIME', 'DATE'))) {
        return DateTime->from_epoch(epoch => str2time($data));
-    } elsif ( grep( /^$type$/, ('int', 'double', 'string', 'boolean'))) {
-        return $data;
+    } elsif ( grep( /^$type$/, ('int', 'double'))) {
+        return $data + 0;
+    } elsif ($type eq 'string') {
+        return $data . q();
+    } elsif ($type eq 'boolean') {
+        return !!$data;
    } else { # hash(model)
        my $_instance = eval "WWW::OpenAPIClient::Object::$type->new()";
        return $_instance->from_hash($data);
--- a/samples/client/petstore/perl/lib/WWW/OpenAPIClient/Object/Animal.pm
+++ b/samples/client/petstore/perl/lib/WWW/OpenAPIClient/Object/Animal.pm
@@ -100,13 +100,60 @@ sub TO_JSON {
    my $_data = {};
    foreach my $_key (keys %{$self->attribute_map}) {
        if (defined $self->{$_key}) {
-            $_data->{$self->attribute_map->{$_key}} = $self->{$_key};
+            my $_json_attribute = $self->attribute_map->{$_key};
+            my $_type = $self->openapi_types->{$_key};
+            my $_value = $self->{$_key};
+            if ($_type =~ /^array\[(.+)\]$/i) { # array
+                my $_subclass = $1;
+                $_data->{$_json_attribute} =  [ map { $self->_to_json_primitives($_subclass, $_) } @$_value ];
+            } elsif ($_type =~ /^hash\[string,(.+)\]$/i) { # hash
+                my $_subclass = $1;
+                my %_hash = ();
+                while (my($_key, $_element) = each %{$_value}) {
+                    $_hash{$_key} = $self->_to_json_primitives($_subclass, $_element);
+                }
+                $_data->{$_json_attribute} = \%_hash;
+            } elsif ( grep( /^$_type$/, ('int', 'double', 'string', 'boolean', 'DATE', 'DATE_TIME'))) {
+                $_data->{$_json_attribute} = $self->_to_json_primitives($_type, $_value);
+            } else {
+                $_data->{$_json_attribute} = $_value;
+            }
        }
    }

    return $_data;
 }

+# to_json non-array data
+sub _to_json_primitives {
+    my ($self, $type, $data) = @_;
+    if ( grep( /^$type$/, ('int', 'double'))) {
+        # https://metacpan.org/pod/JSON#simple-scalars
+        # numify it, ensuring it will be dumped as a number
+        return $data + 0;
+    } elsif ($type eq 'string') {
+        # https://metacpan.org/pod/JSON#simple-scalars
+        # stringified
+        return $data . q();
+    } elsif ($type eq 'boolean') {
+        # https://metacpan.org/pod/JSON#JSON::true,-JSON::false,-JSON::null
+        return $data ? \1 : \0;
+    } elsif ($type eq 'DATE') {
+        if (ref($data) eq 'DateTime') {
+            # https://metacpan.org/pod/DateTime#$dt-%3Eymd($optional_separator),-$dt-%3Emdy(...),-$dt-%3Edmy(...)
+            return $data->ymd;
+        }
+        return $data .q();
+    } elsif ($type eq 'DATE_TIME') {
+        # the date-time notation as defined by RFC 3339, section 5.6, for example, 2017-07-21T17:32:28Z
+        if (ref($data) eq 'DateTime') {
+            # https://metacpan.org/pod/DateTime#$dt-%3Erfc3339
+            return $data->rfc3339;
+        }
+        return $data .q();
+    }
+}
+
 # from Perl hashref
 sub from_hash {
    my ($self, $hash) = @_;
@@ -143,10 +190,14 @@ sub _deserialize {
    my ($self, $type, $data) = @_;
    $log->debugf("deserializing %s with %s",Dumper($data), $type);

-    if ($type eq 'DateTime') {
+    if (grep( /^$type$/ , ('DATE_TIME', 'DATE'))) {
        return DateTime->from_epoch(epoch => str2time($data));
-    } elsif ( grep( /^$type$/, ('int', 'double', 'string', 'boolean'))) {
-        return $data;
+    } elsif ( grep( /^$type$/, ('int', 'double'))) {
+        return $data + 0;
+    } elsif ($type eq 'string') {
+        return $data . q();
+    } elsif ($type eq 'boolean') {
+        return !!$data;
    } else { # hash(model)
        my $_instance = eval "WWW::OpenAPIClient::Object::$type->new()";
        return $_instance->from_hash($data);
--- a/samples/client/petstore/perl/lib/WWW/OpenAPIClient/Object/ApiResponse.pm
+++ b/samples/client/petstore/perl/lib/WWW/OpenAPIClient/Object/ApiResponse.pm
@@ -100,13 +100,60 @@ sub TO_JSON {
    my $_data = {};
    foreach my $_key (keys %{$self->attribute_map}) {
        if (defined $self->{$_key}) {
-            $_data->{$self->attribute_map->{$_key}} = $self->{$_key};
+            my $_json_attribute = $self->attribute_map->{$_key};
+            my $_type = $self->openapi_types->{$_key};
+            my $_value = $self->{$_key};
+            if ($_type =~ /^array\[(.+)\]$/i) { # array
+                my $_subclass = $1;
+                $_data->{$_json_attribute} =  [ map { $self->_to_json_primitives($_subclass, $_) } @$_value ];
+            } elsif ($_type =~ /^hash\[string,(.+)\]$/i) { # hash
+                my $_subclass = $1;
+                my %_hash = ();
+                while (my($_key, $_element) = each %{$_value}) {
+                    $_hash{$_key} = $self->_to_json_primitives($_subclass, $_element);
+                }
+                $_data->{$_json_attribute} = \%_hash;
+            } elsif ( grep( /^$_type$/, ('int', 'double', 'string', 'boolean', 'DATE', 'DATE_TIME'))) {
+                $_data->{$_json_attribute} = $self->_to_json_primitives($_type, $_value);
+            } else {
+                $_data->{$_json_attribute} = $_value;
+            }
        }
    }

    return $_data;
 }

+# to_json non-array data
+sub _to_json_primitives {
+    my ($self, $type, $data) = @_;
+    if ( grep( /^$type$/, ('int', 'double'))) {
+        # https://metacpan.org/pod/JSON#simple-scalars
+        # numify it, ensuring it will be dumped as a number
+        return $data + 0;
+    } elsif ($type eq 'string') {
+        # https://metacpan.org/pod/JSON#simple-scalars
+        # stringified
+        return $data . q();
+    } elsif ($type eq 'boolean') {
+        # https://metacpan.org/pod/JSON#JSON::true,-JSON::false,-JSON::null
+        return $data ? \1 : \0;
+    } elsif ($type eq 'DATE') {
+        if (ref($data) eq 'DateTime') {
+            # https://metacpan.org/pod/DateTime#$dt-%3Eymd($optional_separator),-$dt-%3Emdy(...),-$dt-%3Edmy(...)
+            return $data->ymd;
+        }
+        return $data .q();
+    } elsif ($type eq 'DATE_TIME') {
+        # the date-time notation as defined by RFC 3339, section 5.6, for example, 2017-07-21T17:32:28Z
+        if (ref($data) eq 'DateTime') {
+            # https://metacpan.org/pod/DateTime#$dt-%3Erfc3339
+            return $data->rfc3339;
+        }
+        return $data .q();
+    }
+}
+
 # from Perl hashref
 sub from_hash {
    my ($self, $hash) = @_;
@@ -143,10 +190,14 @@ sub _deserialize {
    my ($self, $type, $data) = @_;
    $log->debugf("deserializing %s with %s",Dumper($data), $type);

-    if ($type eq 'DateTime') {
+    if (grep( /^$type$/ , ('DATE_TIME', 'DATE'))) {
        return DateTime->from_epoch(epoch => str2time($data));
-    } elsif ( grep( /^$type$/, ('int', 'double', 'string', 'boolean'))) {
-        return $data;
+    } elsif ( grep( /^$type$/, ('int', 'double'))) {
+        return $data + 0;
+    } elsif ($type eq 'string') {
+        return $data . q();
+    } elsif ($type eq 'boolean') {
+        return !!$data;
    } else { # hash(model)
        my $_instance = eval "WWW::OpenAPIClient::Object::$type->new()";
        return $_instance->from_hash($data);
--- a/samples/client/petstore/perl/lib/WWW/OpenAPIClient/Object/ArrayOfArrayOfNumberOnly.pm
+++ b/samples/client/petstore/perl/lib/WWW/OpenAPIClient/Object/ArrayOfArrayOfNumberOnly.pm
@@ -100,13 +100,60 @@ sub TO_JSON {
    my $_data = {};
    foreach my $_key (keys %{$self->attribute_map}) {
        if (defined $self->{$_key}) {
-            $_data->{$self->attribute_map->{$_key}} = $self->{$_key};
+            my $_json_attribute = $self->attribute_map->{$_key};
+            my $_type = $self->openapi_types->{$_key};
+            my $_value = $self->{$_key};
+            if ($_type =~ /^array\[(.+)\]$/i) { # array
+                my $_subclass = $1;
+                $_data->{$_json_attribute} =  [ map { $self->_to_json_primitives($_subclass, $_) } @$_value ];
+            } elsif ($_type =~ /^hash\[string,(.+)\]$/i) { # hash
+                my $_subclass = $1;
+                my %_hash = ();
+                while (my($_key, $_element) = each %{$_value}) {
+                    $_hash{$_key} = $self->_to_json_primitives($_subclass, $_element);
+                }
+                $_data->{$_json_attribute} = \%_hash;
+            } elsif ( grep( /^$_type$/, ('int', 'double', 'string', 'boolean', 'DATE', 'DATE_TIME'))) {
+                $_data->{$_json_attribute} = $self->_to_json_primitives($_type, $_value);
+            } else {
+                $_data->{$_json_attribute} = $_value;
+            }
        }
    }

    return $_data;
 }

+# to_json non-array data
+sub _to_json_primitives {
+    my ($self, $type, $data) = @_;
+    if ( grep( /^$type$/, ('int', 'double'))) {
+        # https://metacpan.org/pod/JSON#simple-scalars
+        # numify it, ensuring it will be dumped as a number
+        return $data + 0;
+    } elsif ($type eq 'string') {
+        # https://metacpan.org/pod/JSON#simple-scalars
+        # stringified
+        return $data . q();
+    } elsif ($type eq 'boolean') {
+        # https://metacpan.org/pod/JSON#JSON::true,-JSON::false,-JSON::null
+        return $data ? \1 : \0;
+    } elsif ($type eq 'DATE') {
+        if (ref($data) eq 'DateTime') {
+            # https://metacpan.org/pod/DateTime#$dt-%3Eymd($optional_separator),-$dt-%3Emdy(...),-$dt-%3Edmy(...)
+            return $data->ymd;
+        }
+        return $data .q();
+    } elsif ($type eq 'DATE_TIME') {
+        # the date-time notation as defined by RFC 3339, section 5.6, for example, 2017-07-21T17:32:28Z
+        if (ref($data) eq 'DateTime') {
+            # https://metacpan.org/pod/DateTime#$dt-%3Erfc3339
+            return $data->rfc3339;
+        }
+        return $data .q();
+    }
+}
+
 # from Perl hashref
 sub from_hash {
    my ($self, $hash) = @_;
@@ -143,10 +190,14 @@ sub _deserialize {
    my ($self, $type, $data) = @_;
    $log->debugf("deserializing %s with %s",Dumper($data), $type);

-    if ($type eq 'DateTime') {
+    if (grep( /^$type$/ , ('DATE_TIME', 'DATE'))) {
        return DateTime->from_epoch(epoch => str2time($data));
-    } elsif ( grep( /^$type$/, ('int', 'double', 'string', 'boolean'))) {
-        return $data;
+    } elsif ( grep( /^$type$/, ('int', 'double'))) {
+        return $data + 0;
+    } elsif ($type eq 'string') {
+        return $data . q();
+    } elsif ($type eq 'boolean') {
+        return !!$data;
    } else { # hash(model)
        my $_instance = eval "WWW::OpenAPIClient::Object::$type->new()";
        return $_instance->from_hash($data);
--- a/samples/client/petstore/perl/lib/WWW/OpenAPIClient/Object/ArrayOfNumberOnly.pm
+++ b/samples/client/petstore/perl/lib/WWW/OpenAPIClient/Object/ArrayOfNumberOnly.pm
@@ -100,13 +100,60 @@ sub TO_JSON {
    my $_data = {};
    foreach my $_key (keys %{$self->attribute_map}) {
        if (defined $self->{$_key}) {
-            $_data->{$self->attribute_map->{$_key}} = $self->{$_key};
+            my $_json_attribute = $self->attribute_map->{$_key};
+            my $_type = $self->openapi_types->{$_key};
+            my $_value = $self->{$_key};
+            if ($_type =~ /^array\[(.+)\]$/i) { # array
+                my $_subclass = $1;
+                $_data->{$_json_attribute} =  [ map { $self->_to_json_primitives($_subclass, $_) } @$_value ];
+            } elsif ($_type =~ /^hash\[string,(.+)\]$/i) { # hash
+                my $_subclass = $1;
+                my %_hash = ();
+                while (my($_key, $_element) = each %{$_value}) {
+                    $_hash{$_key} = $self->_to_json_primitives($_subclass, $_element);
+                }
+                $_data->{$_json_attribute} = \%_hash;
+            } elsif ( grep( /^$_type$/, ('int', 'double', 'string', 'boolean', 'DATE', 'DATE_TIME'))) {
+                $_data->{$_json_attribute} = $self->_to_json_primitives($_type, $_value);
+            } else {
+                $_data->{$_json_attribute} = $_value;
+            }
        }
    }

    return $_data;
 }

+# to_json non-array data
+sub _to_json_primitives {
+    my ($self, $type, $data) = @_;
+    if ( grep( /^$type$/, ('int', 'double'))) {
+        # https://metacpan.org/pod/JSON#simple-scalars
+        # numify it, ensuring it will be dumped as a number
+        return $data + 0;
+    } elsif ($type eq 'string') {
+        # https://metacpan.org/pod/JSON#simple-scalars
+        # stringified
+        return $data . q();
+    } elsif ($type eq 'boolean') {
+        # https://metacpan.org/pod/JSON#JSON::true,-JSON::false,-JSON::null
+        return $data ? \1 : \0;
+    } elsif ($type eq 'DATE') {
+        if (ref($data) eq 'DateTime') {
+            # https://metacpan.org/pod/DateTime#$dt-%3Eymd($optional_separator),-$dt-%3Emdy(...),-$dt-%3Edmy(...)
+            return $data->ymd;
+        }
+        return $data .q();
+    } elsif ($type eq 'DATE_TIME') {
+        # the date-time notation as defined by RFC 3339, section 5.6, for example, 2017-07-21T17:32:28Z
+        if (ref($data) eq 'DateTime') {
+            # https://metacpan.org/pod/DateTime#$dt-%3Erfc3339
+            return $data->rfc3339;
+        }
+        return $data .q();
+    }
+}
+
 # from Perl hashref
 sub from_hash {
    my ($self, $hash) = @_;
@@ -143,10 +190,14 @@ sub _deserialize {
    my ($self, $type, $data) = @_;
    $log->debugf("deserializing %s with %s",Dumper($data), $type);

-    if ($type eq 'DateTime') {
+    if (grep( /^$type$/ , ('DATE_TIME', 'DATE'))) {
        return DateTime->from_epoch(epoch => str2time($data));
-    } elsif ( grep( /^$type$/, ('int', 'double', 'string', 'boolean'))) {
-        return $data;
+    } elsif ( grep( /^$type$/, ('int', 'double'))) {
+        return $data + 0;
+    } elsif ($type eq 'string') {
+        return $data . q();
+    } elsif ($type eq 'boolean') {
+        return !!$data;
    } else { # hash(model)
        my $_instance = eval "WWW::OpenAPIClient::Object::$type->new()";
        return $_instance->from_hash($data);
--- a/samples/client/petstore/perl/lib/WWW/OpenAPIClient/Object/ArrayTest.pm
+++ b/samples/client/petstore/perl/lib/WWW/OpenAPIClient/Object/ArrayTest.pm
@@ -101,13 +101,60 @@ sub TO_JSON {
    my $_data = {};
    foreach my $_key (keys %{$self->attribute_map}) {
        if (defined $self->{$_key}) {
-            $_data->{$self->attribute_map->{$_key}} = $self->{$_key};
+            my $_json_attribute = $self->attribute_map->{$_key};
+            my $_type = $self->openapi_types->{$_key};
+            my $_value = $self->{$_key};
+            if ($_type =~ /^array\[(.+)\]$/i) { # array
+                my $_subclass = $1;
+                $_data->{$_json_attribute} =  [ map { $self->_to_json_primitives($_subclass, $_) } @$_value ];
+            } elsif ($_type =~ /^hash\[string,(.+)\]$/i) { # hash
+                my $_subclass = $1;
+                my %_hash = ();
+                while (my($_key, $_element) = each %{$_value}) {
+                    $_hash{$_key} = $self->_to_json_primitives($_subclass, $_element);
+                }
+                $_data->{$_json_attribute} = \%_hash;
+            } elsif ( grep( /^$_type$/, ('int', 'double', 'string', 'boolean', 'DATE', 'DATE_TIME'))) {
+                $_data->{$_json_attribute} = $self->_to_json_primitives($_type, $_value);
+            } else {
+                $_data->{$_json_attribute} = $_value;
+            }
        }
    }

    return $_data;
 }

+# to_json non-array data
+sub _to_json_primitives {
+    my ($self, $type, $data) = @_;
+    if ( grep( /^$type$/, ('int', 'double'))) {
+        # https://metacpan.org/pod/JSON#simple-scalars
+        # numify it, ensuring it will be dumped as a number
+        return $data + 0;
+    } elsif ($type eq 'string') {
+        # https://metacpan.org/pod/JSON#simple-scalars
+        # stringified
+        return $data . q();
+    } elsif ($type eq 'boolean') {
+        # https://metacpan.org/pod/JSON#JSON::true,-JSON::false,-JSON::null
+        return $data ? \1 : \0;
+    } elsif ($type eq 'DATE') {
+        if (ref($data) eq 'DateTime') {
+            # https://metacpan.org/pod/DateTime#$dt-%3Eymd($optional_separator),-$dt-%3Emdy(...),-$dt-%3Edmy(...)
+            return $data->ymd;
+        }
+        return $data .q();
+    } elsif ($type eq 'DATE_TIME') {
+        # the date-time notation as defined by RFC 3339, section 5.6, for example, 2017-07-21T17:32:28Z
+        if (ref($data) eq 'DateTime') {
+            # https://metacpan.org/pod/DateTime#$dt-%3Erfc3339
+            return $data->rfc3339;
+        }
+        return $data .q();
+    }
+}
+
 # from Perl hashref
 sub from_hash {
    my ($self, $hash) = @_;
@@ -144,10 +191,14 @@ sub _deserialize {
    my ($self, $type, $data) = @_;
    $log->debugf("deserializing %s with %s",Dumper($data), $type);

-    if ($type eq 'DateTime') {
+    if (grep( /^$type$/ , ('DATE_TIME', 'DATE'))) {
        return DateTime->from_epoch(epoch => str2time($data));
-    } elsif ( grep( /^$type$/, ('int', 'double', 'string', 'boolean'))) {
-        return $data;
+    } elsif ( grep( /^$type$/, ('int', 'double'))) {
+        return $data + 0;
+    } elsif ($type eq 'string') {
+        return $data . q();
+    } elsif ($type eq 'boolean') {
+        return !!$data;
    } else { # hash(model)
        my $_instance = eval "WWW::OpenAPIClient::Object::$type->new()";
        return $_instance->from_hash($data);
--- a/samples/client/petstore/perl/lib/WWW/OpenAPIClient/Object/Capitalization.pm
+++ b/samples/client/petstore/perl/lib/WWW/OpenAPIClient/Object/Capitalization.pm
@@ -100,13 +100,60 @@ sub TO_JSON {
    my $_data = {};
    foreach my $_key (keys %{$self->attribute_map}) {
        if (defined $self->{$_key}) {
-            $_data->{$self->attribute_map->{$_key}} = $self->{$_key};
+            my $_json_attribute = $self->attribute_map->{$_key};
+            my $_type = $self->openapi_types->{$_key};
+            my $_value = $self->{$_key};
+            if ($_type =~ /^array\[(.+)\]$/i) { # array
+                my $_subclass = $1;
+                $_data->{$_json_attribute} =  [ map { $self->_to_json_primitives($_subclass, $_) } @$_value ];
+            } elsif ($_type =~ /^hash\[string,(.+)\]$/i) { # hash
+                my $_subclass = $1;
+                my %_hash = ();
+                while (my($_key, $_element) = each %{$_value}) {
+                    $_hash{$_key} = $self->_to_json_primitives($_subclass, $_element);
+                }
+                $_data->{$_json_attribute} = \%_hash;
+            } elsif ( grep( /^$_type$/, ('int', 'double', 'string', 'boolean', 'DATE', 'DATE_TIME'))) {
+                $_data->{$_json_attribute} = $self->_to_json_primitives($_type, $_value);
+            } else {
+                $_data->{$_json_attribute} = $_value;
+            }
        }
    }

    return $_data;
 }

+# to_json non-array data
+sub _to_json_primitives {
+    my ($self, $type, $data) = @_;
+    if ( grep( /^$type$/, ('int', 'double'))) {
+        # https://metacpan.org/pod/JSON#simple-scalars
+        # numify it, ensuring it will be dumped as a number
+        return $data + 0;
+    } elsif ($type eq 'string') {
+        # https://metacpan.org/pod/JSON#simple-scalars
+        # stringified
+        return $data . q();
+    } elsif ($type eq 'boolean') {
+        # https://metacpan.org/pod/JSON#JSON::true,-JSON::false,-JSON::null
+        return $data ? \1 : \0;
+    } elsif ($type eq 'DATE') {
+        if (ref($data) eq 'DateTime') {
+            # https://metacpan.org/pod/DateTime#$dt-%3Eymd($optional_separator),-$dt-%3Emdy(...),-$dt-%3Edmy(...)
+            return $data->ymd;
+        }
+        return $data .q();
+    } elsif ($type eq 'DATE_TIME') {
+        # the date-time notation as defined by RFC 3339, section 5.6, for example, 2017-07-21T17:32:28Z
+        if (ref($data) eq 'DateTime') {
+            # https://metacpan.org/pod/DateTime#$dt-%3Erfc3339
+            return $data->rfc3339;
+        }
+        return $data .q();
+    }
+}
+
 # from Perl hashref
 sub from_hash {
    my ($self, $hash) = @_;
@@ -143,10 +190,14 @@ sub _deserialize {
    my ($self, $type, $data) = @_;
    $log->debugf("deserializing %s with %s",Dumper($data), $type);

-    if ($type eq 'DateTime') {
+    if (grep( /^$type$/ , ('DATE_TIME', 'DATE'))) {
        return DateTime->from_epoch(epoch => str2time($data));
-    } elsif ( grep( /^$type$/, ('int', 'double', 'string', 'boolean'))) {
-        return $data;
+    } elsif ( grep( /^$type$/, ('int', 'double'))) {
+        return $data + 0;
+    } elsif ($type eq 'string') {
+        return $data . q();
+    } elsif ($type eq 'boolean') {
+        return !!$data;
    } else { # hash(model)
        my $_instance = eval "WWW::OpenAPIClient::Object::$type->new()";
        return $_instance->from_hash($data);
--- a/samples/client/petstore/perl/lib/WWW/OpenAPIClient/Object/Cat.pm
+++ b/samples/client/petstore/perl/lib/WWW/OpenAPIClient/Object/Cat.pm
@@ -107,7 +107,24 @@ sub TO_JSON {
    my $_data = {};
    foreach my $_key (keys %{$self->attribute_map}) {
        if (defined $self->{$_key}) {
-            $_data->{$self->attribute_map->{$_key}} = $self->{$_key};
+            my $_json_attribute = $self->attribute_map->{$_key};
+            my $_type = $self->openapi_types->{$_key};
+            my $_value = $self->{$_key};
+            if ($_type =~ /^array\[(.+)\]$/i) { # array
+                my $_subclass = $1;
+                $_data->{$_json_attribute} =  [ map { $self->_to_json_primitives($_subclass, $_) } @$_value ];
+            } elsif ($_type =~ /^hash\[string,(.+)\]$/i) { # hash
+                my $_subclass = $1;
+                my %_hash = ();
+                while (my($_key, $_element) = each %{$_value}) {
+                    $_hash{$_key} = $self->_to_json_primitives($_subclass, $_element);
+                }
+                $_data->{$_json_attribute} = \%_hash;
+            } elsif ( grep( /^$_type$/, ('int', 'double', 'string', 'boolean', 'DATE', 'DATE_TIME'))) {
+                $_data->{$_json_attribute} = $self->_to_json_primitives($_type, $_value);
+            } else {
+                $_data->{$_json_attribute} = $_value;
+            }
        }
    }

@@ -117,6 +134,36 @@ sub TO_JSON {
    return $_data;
 }

+# to_json non-array data
+sub _to_json_primitives {
+    my ($self, $type, $data) = @_;
+    if ( grep( /^$type$/, ('int', 'double'))) {
+        # https://metacpan.org/pod/JSON#simple-scalars
+        # numify it, ensuring it will be dumped as a number
+        return $data + 0;
+    } elsif ($type eq 'string') {
+        # https://metacpan.org/pod/JSON#simple-scalars
+        # stringified
+        return $data . q();
+    } elsif ($type eq 'boolean') {
+        # https://metacpan.org/pod/JSON#JSON::true,-JSON::false,-JSON::null
+        return $data ? \1 : \0;
+    } elsif ($type eq 'DATE') {
+        if (ref($data) eq 'DateTime') {
+            # https://metacpan.org/pod/DateTime#$dt-%3Eymd($optional_separator),-$dt-%3Emdy(...),-$dt-%3Edmy(...)
+            return $data->ymd;
+        }
+        return $data .q();
+    } elsif ($type eq 'DATE_TIME') {
+        # the date-time notation as defined by RFC 3339, section 5.6, for example, 2017-07-21T17:32:28Z
+        if (ref($data) eq 'DateTime') {
+            # https://metacpan.org/pod/DateTime#$dt-%3Erfc3339
+            return $data->rfc3339;
+        }
+        return $data .q();
+    }
+}
+
 # from Perl hashref
 sub from_hash {
    my ($self, $hash) = @_;
@@ -156,10 +203,14 @@ sub _deserialize {
    my ($self, $type, $data) = @_;
    $log->debugf("deserializing %s with %s",Dumper($data), $type);

-    if ($type eq 'DateTime') {
+    if (grep( /^$type$/ , ('DATE_TIME', 'DATE'))) {
        return DateTime->from_epoch(epoch => str2time($data));
-    } elsif ( grep( /^$type$/, ('int', 'double', 'string', 'boolean'))) {
-        return $data;
+    } elsif ( grep( /^$type$/, ('int', 'double'))) {
+        return $data + 0;
+    } elsif ($type eq 'string') {
+        return $data . q();
+    } elsif ($type eq 'boolean') {
+        return !!$data;
    } else { # hash(model)
        my $_instance = eval "WWW::OpenAPIClient::Object::$type->new()";
        return $_instance->from_hash($data);
--- a/samples/client/petstore/perl/lib/WWW/OpenAPIClient/Object/CatAllOf.pm
+++ b/samples/client/petstore/perl/lib/WWW/OpenAPIClient/Object/CatAllOf.pm
@@ -100,13 +100,60 @@ sub TO_JSON {
    my $_data = {};
    foreach my $_key (keys %{$self->attribute_map}) {
        if (defined $self->{$_key}) {
-            $_data->{$self->attribute_map->{$_key}} = $self->{$_key};
+            my $_json_attribute = $self->attribute_map->{$_key};
+            my $_type = $self->openapi_types->{$_key};
+            my $_value = $self->{$_key};
+            if ($_type =~ /^array\[(.+)\]$/i) { # array
+                my $_subclass = $1;
+                $_data->{$_json_attribute} =  [ map { $self->_to_json_primitives($_subclass, $_) } @$_value ];
+            } elsif ($_type =~ /^hash\[string,(.+)\]$/i) { # hash
+                my $_subclass = $1;
+                my %_hash = ();
+                while (my($_key, $_element) = each %{$_value}) {
+                    $_hash{$_key} = $self->_to_json_primitives($_subclass, $_element);
+                }
+                $_data->{$_json_attribute} = \%_hash;
+            } elsif ( grep( /^$_type$/, ('int', 'double', 'string', 'boolean', 'DATE', 'DATE_TIME'))) {
+                $_data->{$_json_attribute} = $self->_to_json_primitives($_type, $_value);
+            } else {
+                $_data->{$_json_attribute} = $_value;
+            }
        }
    }

    return $_data;
 }

+# to_json non-array data
+sub _to_json_primitives {
+    my ($self, $type, $data) = @_;
+    if ( grep( /^$type$/, ('int', 'double'))) {
+        # https://metacpan.org/pod/JSON#simple-scalars
+        # numify it, ensuring it will be dumped as a number
+        return $data + 0;
+    } elsif ($type eq 'string') {
+        # https://metacpan.org/pod/JSON#simple-scalars
+        # stringified
+        return $data . q();
+    } elsif ($type eq 'boolean') {
+        # https://metacpan.org/pod/JSON#JSON::true,-JSON::false,-JSON::null
+        return $data ? \1 : \0;
+    } elsif ($type eq 'DATE') {
+        if (ref($data) eq 'DateTime') {
+            # https://metacpan.org/pod/DateTime#$dt-%3Eymd($optional_separator),-$dt-%3Emdy(...),-$dt-%3Edmy(...)
+            return $data->ymd;
+        }
+        return $data .q();
+    } elsif ($type eq 'DATE_TIME') {
+        # the date-time notation as defined by RFC 3339, section 5.6, for example, 2017-07-21T17:32:28Z
+        if (ref($data) eq 'DateTime') {
+            # https://metacpan.org/pod/DateTime#$dt-%3Erfc3339
+            return $data->rfc3339;
+        }
+        return $data .q();
+    }
+}
+
 # from Perl hashref
 sub from_hash {
    my ($self, $hash) = @_;
@@ -143,10 +190,14 @@ sub _deserialize {
    my ($self, $type, $data) = @_;
    $log->debugf("deserializing %s with %s",Dumper($data), $type);

-    if ($type eq 'DateTime') {
+    if (grep( /^$type$/ , ('DATE_TIME', 'DATE'))) {
        return DateTime->from_epoch(epoch => str2time($data));
-    } elsif ( grep( /^$type$/, ('int', 'double', 'string', 'boolean'))) {
-        return $data;
+    } elsif ( grep( /^$type$/, ('int', 'double'))) {
+        return $data + 0;
+    } elsif ($type eq 'string') {
+        return $data . q();
+    } elsif ($type eq 'boolean') {
+        return !!$data;
    } else { # hash(model)
        my $_instance = eval "WWW::OpenAPIClient::Object::$type->new()";
        return $_instance->from_hash($data);
--- a/samples/client/petstore/perl/lib/WWW/OpenAPIClient/Object/Category.pm
+++ b/samples/client/petstore/perl/lib/WWW/OpenAPIClient/Object/Category.pm
@@ -100,13 +100,60 @@ sub TO_JSON {
    my $_data = {};
    foreach my $_key (keys %{$self->attribute_map}) {
        if (defined $self->{$_key}) {
-            $_data->{$self->attribute_map->{$_key}} = $self->{$_key};
+            my $_json_attribute = $self->attribute_map->{$_key};
+            my $_type = $self->openapi_types->{$_key};
+            my $_value = $self->{$_key};
+            if ($_type =~ /^array\[(.+)\]$/i) { # array
+                my $_subclass = $1;
+                $_data->{$_json_attribute} =  [ map { $self->_to_json_primitives($_subclass, $_) } @$_value ];
+            } elsif ($_type =~ /^hash\[string,(.+)\]$/i) { # hash
+                my $_subclass = $1;
+                my %_hash = ();
+                while (my($_key, $_element) = each %{$_value}) {
+                    $_hash{$_key} = $self->_to_json_primitives($_subclass, $_element);
+                }
+                $_data->{$_json_attribute} = \%_hash;
+            } elsif ( grep( /^$_type$/, ('int', 'double', 'string', 'boolean', 'DATE', 'DATE_TIME'))) {
+                $_data->{$_json_attribute} = $self->_to_json_primitives($_type, $_value);
+            } else {
+                $_data->{$_json_attribute} = $_value;
+            }
        }
    }

    return $_data;
 }

+# to_json non-array data
+sub _to_json_primitives {
+    my ($self, $type, $data) = @_;
+    if ( grep( /^$type$/, ('int', 'double'))) {
+        # https://metacpan.org/pod/JSON#simple-scalars
+        # numify it, ensuring it will be dumped as a number
+        return $data + 0;
+    } elsif ($type eq 'string') {
+        # https://metacpan.org/pod/JSON#simple-scalars
+        # stringified
+        return $data . q();
+    } elsif ($type eq 'boolean') {
+        # https://metacpan.org/pod/JSON#JSON::true,-JSON::false,-JSON::null
+        return $data ? \1 : \0;
+    } elsif ($type eq 'DATE') {
+        if (ref($data) eq 'DateTime') {
+            # https://metacpan.org/pod/DateTime#$dt-%3Eymd($optional_separator),-$dt-%3Emdy(...),-$dt-%3Edmy(...)
+            return $data->ymd;
+        }
+        return $data .q();
+    } elsif ($type eq 'DATE_TIME') {
+        # the date-time notation as defined by RFC 3339, section 5.6, for example, 2017-07-21T17:32:28Z
+        if (ref($data) eq 'DateTime') {
+            # https://metacpan.org/pod/DateTime#$dt-%3Erfc3339
+            return $data->rfc3339;
+        }
+        return $data .q();
+    }
+}
+
 # from Perl hashref
 sub from_hash {
    my ($self, $hash) = @_;
@@ -143,10 +190,14 @@ sub _deserialize {
    my ($self, $type, $data) = @_;
    $log->debugf("deserializing %s with %s",Dumper($data), $type);

-    if ($type eq 'DateTime') {
+    if (grep( /^$type$/ , ('DATE_TIME', 'DATE'))) {
        return DateTime->from_epoch(epoch => str2time($data));
-    } elsif ( grep( /^$type$/, ('int', 'double', 'string', 'boolean'))) {
-        return $data;
+    } elsif ( grep( /^$type$/, ('int', 'double'))) {
+        return $data + 0;
+    } elsif ($type eq 'string') {
+        return $data . q();
+    } elsif ($type eq 'boolean') {
+        return !!$data;
    } else { # hash(model)
        my $_instance = eval "WWW::OpenAPIClient::Object::$type->new()";
        return $_instance->from_hash($data);
--- a/samples/client/petstore/perl/lib/WWW/OpenAPIClient/Object/ClassModel.pm
+++ b/samples/client/petstore/perl/lib/WWW/OpenAPIClient/Object/ClassModel.pm
@@ -100,13 +100,60 @@ sub TO_JSON {
    my $_data = {};
    foreach my $_key (keys %{$self->attribute_map}) {
        if (defined $self->{$_key}) {
-            $_data->{$self->attribute_map->{$_key}} = $self->{$_key};
+            my $_json_attribute = $self->attribute_map->{$_key};
+            my $_type = $self->openapi_types->{$_key};
+            my $_value = $self->{$_key};
+            if ($_type =~ /^array\[(.+)\]$/i) { # array
+                my $_subclass = $1;
+                $_data->{$_json_attribute} =  [ map { $self->_to_json_primitives($_subclass, $_) } @$_value ];
+            } elsif ($_type =~ /^hash\[string,(.+)\]$/i) { # hash
+                my $_subclass = $1;
+                my %_hash = ();
+                while (my($_key, $_element) = each %{$_value}) {
+                    $_hash{$_key} = $self->_to_json_primitives($_subclass, $_element);
+                }
+                $_data->{$_json_attribute} = \%_hash;
+            } elsif ( grep( /^$_type$/, ('int', 'double', 'string', 'boolean', 'DATE', 'DATE_TIME'))) {
+                $_data->{$_json_attribute} = $self->_to_json_primitives($_type, $_value);
+            } else {
+                $_data->{$_json_attribute} = $_value;
+            }
        }
    }

    return $_data;
 }

+# to_json non-array data
+sub _to_json_primitives {
+    my ($self, $type, $data) = @_;
+    if ( grep( /^$type$/, ('int', 'double'))) {
+        # https://metacpan.org/pod/JSON#simple-scalars
+        # numify it, ensuring it will be dumped as a number
+        return $data + 0;
+    } elsif ($type eq 'string') {
+        # https://metacpan.org/pod/JSON#simple-scalars
+        # stringified
+        return $data . q();
+    } elsif ($type eq 'boolean') {
+        # https://metacpan.org/pod/JSON#JSON::true,-JSON::false,-JSON::null
+        return $data ? \1 : \0;
+    } elsif ($type eq 'DATE') {
+        if (ref($data) eq 'DateTime') {
+            # https://metacpan.org/pod/DateTime#$dt-%3Eymd($optional_separator),-$dt-%3Emdy(...),-$dt-%3Edmy(...)
+            return $data->ymd;
+        }
+        return $data .q();
+    } elsif ($type eq 'DATE_TIME') {
+        # the date-time notation as defined by RFC 3339, section 5.6, for example, 2017-07-21T17:32:28Z
+        if (ref($data) eq 'DateTime') {
+            # https://metacpan.org/pod/DateTime#$dt-%3Erfc3339
+            return $data->rfc3339;
+        }
+        return $data .q();
+    }
+}
+
 # from Perl hashref
 sub from_hash {
    my ($self, $hash) = @_;
@@ -143,10 +190,14 @@ sub _deserialize {
    my ($self, $type, $data) = @_;
    $log->debugf("deserializing %s with %s",Dumper($data), $type);

-    if ($type eq 'DateTime') {
+    if (grep( /^$type$/ , ('DATE_TIME', 'DATE'))) {
        return DateTime->from_epoch(epoch => str2time($data));
-    } elsif ( grep( /^$type$/, ('int', 'double', 'string', 'boolean'))) {
-        return $data;
+    } elsif ( grep( /^$type$/, ('int', 'double'))) {
+        return $data + 0;
+    } elsif ($type eq 'string') {
+        return $data . q();
+    } elsif ($type eq 'boolean') {
+        return !!$data;
    } else { # hash(model)
        my $_instance = eval "WWW::OpenAPIClient::Object::$type->new()";
        return $_instance->from_hash($data);
--- a/samples/client/petstore/perl/lib/WWW/OpenAPIClient/Object/Client.pm
+++ b/samples/client/petstore/perl/lib/WWW/OpenAPIClient/Object/Client.pm
@@ -100,13 +100,60 @@ sub TO_JSON {
    my $_data = {};
    foreach my $_key (keys %{$self->attribute_map}) {
        if (defined $self->{$_key}) {
-            $_data->{$self->attribute_map->{$_key}} = $self->{$_key};
+            my $_json_attribute = $self->attribute_map->{$_key};
+            my $_type = $self->openapi_types->{$_key};
+            my $_value = $self->{$_key};
+            if ($_type =~ /^array\[(.+)\]$/i) { # array
+                my $_subclass = $1;
+                $_data->{$_json_attribute} =  [ map { $self->_to_json_primitives($_subclass, $_) } @$_value ];
+            } elsif ($_type =~ /^hash\[string,(.+)\]$/i) { # hash
+                my $_subclass = $1;
+                my %_hash = ();
+                while (my($_key, $_element) = each %{$_value}) {
+                    $_hash{$_key} = $self->_to_json_primitives($_subclass, $_element);
+                }
+                $_data->{$_json_attribute} = \%_hash;
+            } elsif ( grep( /^$_type$/, ('int', 'double', 'string', 'boolean', 'DATE', 'DATE_TIME'))) {
+                $_data->{$_json_attribute} = $self->_to_json_primitives($_type, $_value);
+            } else {
+                $_data->{$_json_attribute} = $_value;
+            }
        }
    }

    return $_data;
 }

+# to_json non-array data
+sub _to_json_primitives {
+    my ($self, $type, $data) = @_;
+    if ( grep( /^$type$/, ('int', 'double'))) {
+        # https://metacpan.org/pod/JSON#simple-scalars
+        # numify it, ensuring it will be dumped as a number
+        return $data + 0;
+    } elsif ($type eq 'string') {
+        # https://metacpan.org/pod/JSON#simple-scalars
+        # stringified
+        return $data . q();
+    } elsif ($type eq 'boolean') {
+        # https://metacpan.org/pod/JSON#JSON::true,-JSON::false,-JSON::null
+        return $data ? \1 : \0;
+    } elsif ($type eq 'DATE') {
+        if (ref($data) eq 'DateTime') {
+            # https://metacpan.org/pod/DateTime#$dt-%3Eymd($optional_separator),-$dt-%3Emdy(...),-$dt-%3Edmy(...)
+            return $data->ymd;
+        }
+        return $data .q();
+    } elsif ($type eq 'DATE_TIME') {
+        # the date-time notation as defined by RFC 3339, section 5.6, for example, 2017-07-21T17:32:28Z
+        if (ref($data) eq 'DateTime') {
+            # https://metacpan.org/pod/DateTime#$dt-%3Erfc3339
+            return $data->rfc3339;
+        }
+        return $data .q();
+    }
+}
+
 # from Perl hashref
 sub from_hash {
    my ($self, $hash) = @_;
@@ -143,10 +190,14 @@ sub _deserialize {
    my ($self, $type, $data) = @_;
    $log->debugf("deserializing %s with %s",Dumper($data), $type);

-    if ($type eq 'DateTime') {
+    if (grep( /^$type$/ , ('DATE_TIME', 'DATE'))) {
        return DateTime->from_epoch(epoch => str2time($data));
-    } elsif ( grep( /^$type$/, ('int', 'double', 'string', 'boolean'))) {
-        return $data;
+    } elsif ( grep( /^$type$/, ('int', 'double'))) {
+        return $data + 0;
+    } elsif ($type eq 'string') {
+        return $data . q();
+    } elsif ($type eq 'boolean') {
+        return !!$data;
    } else { # hash(model)
        my $_instance = eval "WWW::OpenAPIClient::Object::$type->new()";
        return $_instance->from_hash($data);
--- a/samples/client/petstore/perl/lib/WWW/OpenAPIClient/Object/DeprecatedObject.pm
+++ b/samples/client/petstore/perl/lib/WWW/OpenAPIClient/Object/DeprecatedObject.pm
@@ -100,13 +100,60 @@ sub TO_JSON {
    my $_data = {};
    foreach my $_key (keys %{$self->attribute_map}) {
        if (defined $self->{$_key}) {
-            $_data->{$self->attribute_map->{$_key}} = $self->{$_key};
+            my $_json_attribute = $self->attribute_map->{$_key};
+            my $_type = $self->openapi_types->{$_key};
+            my $_value = $self->{$_key};
+            if ($_type =~ /^array\[(.+)\]$/i) { # array
+                my $_subclass = $1;
+                $_data->{$_json_attribute} =  [ map { $self->_to_json_primitives($_subclass, $_) } @$_value ];
+            } elsif ($_type =~ /^hash\[string,(.+)\]$/i) { # hash
+                my $_subclass = $1;
+                my %_hash = ();
+                while (my($_key, $_element) = each %{$_value}) {
+                    $_hash{$_key} = $self->_to_json_primitives($_subclass, $_element);
+                }
+                $_data->{$_json_attribute} = \%_hash;
+            } elsif ( grep( /^$_type$/, ('int', 'double', 'string', 'boolean', 'DATE', 'DATE_TIME'))) {
+                $_data->{$_json_attribute} = $self->_to_json_primitives($_type, $_value);
+            } else {
+                $_data->{$_json_attribute} = $_value;
+            }
        }
    }

    return $_data;
 }

+# to_json non-array data
+sub _to_json_primitives {
+    my ($self, $type, $data) = @_;
+    if ( grep( /^$type$/, ('int', 'double'))) {
+        # https://metacpan.org/pod/JSON#simple-scalars
+        # numify it, ensuring it will be dumped as a number
+        return $data + 0;
+    } elsif ($type eq 'string') {
+        # https://metacpan.org/pod/JSON#simple-scalars
+        # stringified
+        return $data . q();
+    } elsif ($type eq 'boolean') {
+        # https://metacpan.org/pod/JSON#JSON::true,-JSON::false,-JSON::null
+        return $data ? \1 : \0;
+    } elsif ($type eq 'DATE') {
+        if (ref($data) eq 'DateTime') {
+            # https://metacpan.org/pod/DateTime#$dt-%3Eymd($optional_separator),-$dt-%3Emdy(...),-$dt-%3Edmy(...)
+            return $data->ymd;
+        }
+        return $data .q();
+    } elsif ($type eq 'DATE_TIME') {
+        # the date-time notation as defined by RFC 3339, section 5.6, for example, 2017-07-21T17:32:28Z
+        if (ref($data) eq 'DateTime') {
+            # https://metacpan.org/pod/DateTime#$dt-%3Erfc3339
+            return $data->rfc3339;
+        }
+        return $data .q();
+    }
+}
+
 # from Perl hashref
 sub from_hash {
    my ($self, $hash) = @_;
@@ -143,10 +190,14 @@ sub _deserialize {
    my ($self, $type, $data) = @_;
    $log->debugf("deserializing %s with %s",Dumper($data), $type);

-    if ($type eq 'DateTime') {
+    if (grep( /^$type$/ , ('DATE_TIME', 'DATE'))) {
        return DateTime->from_epoch(epoch => str2time($data));
-    } elsif ( grep( /^$type$/, ('int', 'double', 'string', 'boolean'))) {
-        return $data;
+    } elsif ( grep( /^$type$/, ('int', 'double'))) {
+        return $data + 0;
+    } elsif ($type eq 'string') {
+        return $data . q();
+    } elsif ($type eq 'boolean') {
+        return !!$data;
    } else { # hash(model)
        my $_instance = eval "WWW::OpenAPIClient::Object::$type->new()";
        return $_instance->from_hash($data);
--- a/samples/client/petstore/perl/lib/WWW/OpenAPIClient/Object/Dog.pm
+++ b/samples/client/petstore/perl/lib/WWW/OpenAPIClient/Object/Dog.pm
@@ -107,7 +107,24 @@ sub TO_JSON {
    my $_data = {};
    foreach my $_key (keys %{$self->attribute_map}) {
        if (defined $self->{$_key}) {
-            $_data->{$self->attribute_map->{$_key}} = $self->{$_key};
+            my $_json_attribute = $self->attribute_map->{$_key};
+            my $_type = $self->openapi_types->{$_key};
+            my $_value = $self->{$_key};
+            if ($_type =~ /^array\[(.+)\]$/i) { # array
+                my $_subclass = $1;
+                $_data->{$_json_attribute} =  [ map { $self->_to_json_primitives($_subclass, $_) } @$_value ];
+            } elsif ($_type =~ /^hash\[string,(.+)\]$/i) { # hash
+                my $_subclass = $1;
+                my %_hash = ();
+                while (my($_key, $_element) = each %{$_value}) {
+                    $_hash{$_key} = $self->_to_json_primitives($_subclass, $_element);
+                }
+                $_data->{$_json_attribute} = \%_hash;
+            } elsif ( grep( /^$_type$/, ('int', 'double', 'string', 'boolean', 'DATE', 'DATE_TIME'))) {
+                $_data->{$_json_attribute} = $self->_to_json_primitives($_type, $_value);
+            } else {
+                $_data->{$_json_attribute} = $_value;
+            }
        }
    }

@@ -117,6 +134,36 @@ sub TO_JSON {
    return $_data;
 }

+# to_json non-array data
+sub _to_json_primitives {
+    my ($self, $type, $data) = @_;
+    if ( grep( /^$type$/, ('int', 'double'))) {
+        # https://metacpan.org/pod/JSON#simple-scalars
+        # numify it, ensuring it will be dumped as a number
+        return $data + 0;
+    } elsif ($type eq 'string') {
+        # https://metacpan.org/pod/JSON#simple-scalars
+        # stringified
+        return $data . q();
+    } elsif ($type eq 'boolean') {
+        # https://metacpan.org/pod/JSON#JSON::true,-JSON::false,-JSON::null
+        return $data ? \1 : \0;
+    } elsif ($type eq 'DATE') {
+        if (ref($data) eq 'DateTime') {
+            # https://metacpan.org/pod/DateTime#$dt-%3Eymd($optional_separator),-$dt-%3Emdy(...),-$dt-%3Edmy(...)
+            return $data->ymd;
+        }
+        return $data .q();
+    } elsif ($type eq 'DATE_TIME') {
+        # the date-time notation as defined by RFC 3339, section 5.6, for example, 2017-07-21T17:32:28Z
+        if (ref($data) eq 'DateTime') {
+            # https://metacpan.org/pod/DateTime#$dt-%3Erfc3339
+            return $data->rfc3339;
+        }
+        return $data .q();
+    }
+}
+
 # from Perl hashref
 sub from_hash {
    my ($self, $hash) = @_;
@@ -156,10 +203,14 @@ sub _deserialize {
    my ($self, $type, $data) = @_;
    $log->debugf("deserializing %s with %s",Dumper($data), $type);

-    if ($type eq 'DateTime') {
+    if (grep( /^$type$/ , ('DATE_TIME', 'DATE'))) {
        return DateTime->from_epoch(epoch => str2time($data));
-    } elsif ( grep( /^$type$/, ('int', 'double', 'string', 'boolean'))) {
-        return $data;
+    } elsif ( grep( /^$type$/, ('int', 'double'))) {
+        return $data + 0;
+    } elsif ($type eq 'string') {
+        return $data . q();
+    } elsif ($type eq 'boolean') {
+        return !!$data;
    } else { # hash(model)
        my $_instance = eval "WWW::OpenAPIClient::Object::$type->new()";
        return $_instance->from_hash($data);
--- a/samples/client/petstore/perl/lib/WWW/OpenAPIClient/Object/DogAllOf.pm
+++ b/samples/client/petstore/perl/lib/WWW/OpenAPIClient/Object/DogAllOf.pm
@@ -100,13 +100,60 @@ sub TO_JSON {
    my $_data = {};
    foreach my $_key (keys %{$self->attribute_map}) {
        if (defined $self->{$_key}) {
-            $_data->{$self->attribute_map->{$_key}} = $self->{$_key};
+            my $_json_attribute = $self->attribute_map->{$_key};
+            my $_type = $self->openapi_types->{$_key};
+            my $_value = $self->{$_key};
+            if ($_type =~ /^array\[(.+)\]$/i) { # array
+                my $_subclass = $1;
+                $_data->{$_json_attribute} =  [ map { $self->_to_json_primitives($_subclass, $_) } @$_value ];
+            } elsif ($_type =~ /^hash\[string,(.+)\]$/i) { # hash
+                my $_subclass = $1;
+                my %_hash = ();
+                while (my($_key, $_element) = each %{$_value}) {
+                    $_hash{$_key} = $self->_to_json_primitives($_subclass, $_element);
+                }
+                $_data->{$_json_attribute} = \%_hash;
+            } elsif ( grep( /^$_type$/, ('int', 'double', 'string', 'boolean', 'DATE', 'DATE_TIME'))) {
+                $_data->{$_json_attribute} = $self->_to_json_primitives($_type, $_value);
+            } else {
+                $_data->{$_json_attribute} = $_value;
+            }
        }
    }

    return $_data;
 }

+# to_json non-array data
+sub _to_json_primitives {
+    my ($self, $type, $data) = @_;
+    if ( grep( /^$type$/, ('int', 'double'))) {
+        # https://metacpan.org/pod/JSON#simple-scalars
+        # numify it, ensuring it will be dumped as a number
+        return $data + 0;
+    } elsif ($type eq 'string') {
+        # https://metacpan.org/pod/JSON#simple-scalars
+        # stringified
+        return $data . q();
+    } elsif ($type eq 'boolean') {
+        # https://metacpan.org/pod/JSON#JSON::true,-JSON::false,-JSON::null
+        return $data ? \1 : \0;
+    } elsif ($type eq 'DATE') {
+        if (ref($data) eq 'DateTime') {
+            # https://metacpan.org/pod/DateTime#$dt-%3Eymd($optional_separator),-$dt-%3Emdy(...),-$dt-%3Edmy(...)
+            return $data->ymd;
+        }
+        return $data .q();
+    } elsif ($type eq 'DATE_TIME') {
+        # the date-time notation as defined by RFC 3339, section 5.6, for example, 2017-07-21T17:32:28Z
+        if (ref($data) eq 'DateTime') {
+            # https://metacpan.org/pod/DateTime#$dt-%3Erfc3339
+            return $data->rfc3339;
+        }
+        return $data .q();
+    }
+}
+
 # from Perl hashref
 sub from_hash {
    my ($self, $hash) = @_;
@@ -143,10 +190,14 @@ sub _deserialize {
    my ($self, $type, $data) = @_;
    $log->debugf("deserializing %s with %s",Dumper($data), $type);

-    if ($type eq 'DateTime') {
+    if (grep( /^$type$/ , ('DATE_TIME', 'DATE'))) {
        return DateTime->from_epoch(epoch => str2time($data));
-    } elsif ( grep( /^$type$/, ('int', 'double', 'string', 'boolean'))) {
-        return $data;
+    } elsif ( grep( /^$type$/, ('int', 'double'))) {
+        return $data + 0;
+    } elsif ($type eq 'string') {
+        return $data . q();
+    } elsif ($type eq 'boolean') {
+        return !!$data;
    } else { # hash(model)
        my $_instance = eval "WWW::OpenAPIClient::Object::$type->new()";
        return $_instance->from_hash($data);
--- a/samples/client/petstore/perl/lib/WWW/OpenAPIClient/Object/EnumArrays.pm
+++ b/samples/client/petstore/perl/lib/WWW/OpenAPIClient/Object/EnumArrays.pm
@@ -100,13 +100,60 @@ sub TO_JSON {
    my $_data = {};
    foreach my $_key (keys %{$self->attribute_map}) {
        if (defined $self->{$_key}) {
-            $_data->{$self->attribute_map->{$_key}} = $self->{$_key};
+            my $_json_attribute = $self->attribute_map->{$_key};
+            my $_type = $self->openapi_types->{$_key};
+            my $_value = $self->{$_key};
+            if ($_type =~ /^array\[(.+)\]$/i) { # array
+                my $_subclass = $1;
+                $_data->{$_json_attribute} =  [ map { $self->_to_json_primitives($_subclass, $_) } @$_value ];
+            } elsif ($_type =~ /^hash\[string,(.+)\]$/i) { # hash
+                my $_subclass = $1;
+                my %_hash = ();
+                while (my($_key, $_element) = each %{$_value}) {
+                    $_hash{$_key} = $self->_to_json_primitives($_subclass, $_element);
+                }
+                $_data->{$_json_attribute} = \%_hash;
+            } elsif ( grep( /^$_type$/, ('int', 'double', 'string', 'boolean', 'DATE', 'DATE_TIME'))) {
+                $_data->{$_json_attribute} = $self->_to_json_primitives($_type, $_value);
+            } else {
+                $_data->{$_json_attribute} = $_value;
+            }
        }
    }

    return $_data;
 }

+# to_json non-array data
+sub _to_json_primitives {
+    my ($self, $type, $data) = @_;
+    if ( grep( /^$type$/, ('int', 'double'))) {
+        # https://metacpan.org/pod/JSON#simple-scalars
+        # numify it, ensuring it will be dumped as a number
+        return $data + 0;
+    } elsif ($type eq 'string') {
+        # https://metacpan.org/pod/JSON#simple-scalars
+        # stringified
+        return $data . q();
+    } elsif ($type eq 'boolean') {
+        # https://metacpan.org/pod/JSON#JSON::true,-JSON::false,-JSON::null
+        return $data ? \1 : \0;
+    } elsif ($type eq 'DATE') {
+        if (ref($data) eq 'DateTime') {
+            # https://metacpan.org/pod/DateTime#$dt-%3Eymd($optional_separator),-$dt-%3Emdy(...),-$dt-%3Edmy(...)
+            return $data->ymd;
+        }
+        return $data .q();
+    } elsif ($type eq 'DATE_TIME') {
+        # the date-time notation as defined by RFC 3339, section 5.6, for example, 2017-07-21T17:32:28Z
+        if (ref($data) eq 'DateTime') {
+            # https://metacpan.org/pod/DateTime#$dt-%3Erfc3339
+            return $data->rfc3339;
+        }
+        return $data .q();
+    }
+}
+
 # from Perl hashref
 sub from_hash {
    my ($self, $hash) = @_;
@@ -143,10 +190,14 @@ sub _deserialize {
    my ($self, $type, $data) = @_;
    $log->debugf("deserializing %s with %s",Dumper($data), $type);

-    if ($type eq 'DateTime') {
+    if (grep( /^$type$/ , ('DATE_TIME', 'DATE'))) {
        return DateTime->from_epoch(epoch => str2time($data));
-    } elsif ( grep( /^$type$/, ('int', 'double', 'string', 'boolean'))) {
-        return $data;
+    } elsif ( grep( /^$type$/, ('int', 'double'))) {
+        return $data + 0;
+    } elsif ($type eq 'string') {
+        return $data . q();
+    } elsif ($type eq 'boolean') {
+        return !!$data;
    } else { # hash(model)
        my $_instance = eval "WWW::OpenAPIClient::Object::$type->new()";
        return $_instance->from_hash($data);
--- a/samples/client/petstore/perl/lib/WWW/OpenAPIClient/Object/EnumClass.pm
+++ b/samples/client/petstore/perl/lib/WWW/OpenAPIClient/Object/EnumClass.pm
@@ -100,13 +100,60 @@ sub TO_JSON {
    my $_data = {};
    foreach my $_key (keys %{$self->attribute_map}) {
        if (defined $self->{$_key}) {
-            $_data->{$self->attribute_map->{$_key}} = $self->{$_key};
+            my $_json_attribute = $self->attribute_map->{$_key};
+            my $_type = $self->openapi_types->{$_key};
+            my $_value = $self->{$_key};
+            if ($_type =~ /^array\[(.+)\]$/i) { # array
+                my $_subclass = $1;
+                $_data->{$_json_attribute} =  [ map { $self->_to_json_primitives($_subclass, $_) } @$_value ];
+            } elsif ($_type =~ /^hash\[string,(.+)\]$/i) { # hash
+                my $_subclass = $1;
+                my %_hash = ();
+                while (my($_key, $_element) = each %{$_value}) {
+                    $_hash{$_key} = $self->_to_json_primitives($_subclass, $_element);
+                }
+                $_data->{$_json_attribute} = \%_hash;
+            } elsif ( grep( /^$_type$/, ('int', 'double', 'string', 'boolean', 'DATE', 'DATE_TIME'))) {
+                $_data->{$_json_attribute} = $self->_to_json_primitives($_type, $_value);
+            } else {
+                $_data->{$_json_attribute} = $_value;
+            }
        }
    }

    return $_data;
 }

+# to_json non-array data
+sub _to_json_primitives {
+    my ($self, $type, $data) = @_;
+    if ( grep( /^$type$/, ('int', 'double'))) {
+        # https://metacpan.org/pod/JSON#simple-scalars
+        # numify it, ensuring it will be dumped as a number
+        return $data + 0;
+    } elsif ($type eq 'string') {
+        # https://metacpan.org/pod/JSON#simple-scalars
+        # stringified
+        return $data . q();
+    } elsif ($type eq 'boolean') {
+        # https://metacpan.org/pod/JSON#JSON::true,-JSON::false,-JSON::null
+        return $data ? \1 : \0;
+    } elsif ($type eq 'DATE') {
+        if (ref($data) eq 'DateTime') {
+            # https://metacpan.org/pod/DateTime#$dt-%3Eymd($optional_separator),-$dt-%3Emdy(...),-$dt-%3Edmy(...)
+            return $data->ymd;
+        }
+        return $data .q();
+    } elsif ($type eq 'DATE_TIME') {
+        # the date-time notation as defined by RFC 3339, section 5.6, for example, 2017-07-21T17:32:28Z
+        if (ref($data) eq 'DateTime') {
+            # https://metacpan.org/pod/DateTime#$dt-%3Erfc3339
+            return $data->rfc3339;
+        }
+        return $data .q();
+    }
+}
+
 # from Perl hashref
 sub from_hash {
    my ($self, $hash) = @_;
@@ -143,10 +190,14 @@ sub _deserialize {
    my ($self, $type, $data) = @_;
    $log->debugf("deserializing %s with %s",Dumper($data), $type);

-    if ($type eq 'DateTime') {
+    if (grep( /^$type$/ , ('DATE_TIME', 'DATE'))) {
        return DateTime->from_epoch(epoch => str2time($data));
-    } elsif ( grep( /^$type$/, ('int', 'double', 'string', 'boolean'))) {
-        return $data;
+    } elsif ( grep( /^$type$/, ('int', 'double'))) {
+        return $data + 0;
+    } elsif ($type eq 'string') {
+        return $data . q();
+    } elsif ($type eq 'boolean') {
+        return !!$data;
    } else { # hash(model)
        my $_instance = eval "WWW::OpenAPIClient::Object::$type->new()";
        return $_instance->from_hash($data);
--- a/samples/client/petstore/perl/lib/WWW/OpenAPIClient/Object/EnumTest.pm
+++ b/samples/client/petstore/perl/lib/WWW/OpenAPIClient/Object/EnumTest.pm
@@ -104,13 +104,60 @@ sub TO_JSON {
    my $_data = {};
    foreach my $_key (keys %{$self->attribute_map}) {
        if (defined $self->{$_key}) {
-            $_data->{$self->attribute_map->{$_key}} = $self->{$_key};
+            my $_json_attribute = $self->attribute_map->{$_key};
+            my $_type = $self->openapi_types->{$_key};
+            my $_value = $self->{$_key};
+            if ($_type =~ /^array\[(.+)\]$/i) { # array
+                my $_subclass = $1;
+                $_data->{$_json_attribute} =  [ map { $self->_to_json_primitives($_subclass, $_) } @$_value ];
+            } elsif ($_type =~ /^hash\[string,(.+)\]$/i) { # hash
+                my $_subclass = $1;
+                my %_hash = ();
+                while (my($_key, $_element) = each %{$_value}) {
+                    $_hash{$_key} = $self->_to_json_primitives($_subclass, $_element);
+                }
+                $_data->{$_json_attribute} = \%_hash;
+            } elsif ( grep( /^$_type$/, ('int', 'double', 'string', 'boolean', 'DATE', 'DATE_TIME'))) {
+                $_data->{$_json_attribute} = $self->_to_json_primitives($_type, $_value);
+            } else {
+                $_data->{$_json_attribute} = $_value;
+            }
        }
    }

    return $_data;
 }

+# to_json non-array data
+sub _to_json_primitives {
+    my ($self, $type, $data) = @_;
+    if ( grep( /^$type$/, ('int', 'double'))) {
+        # https://metacpan.org/pod/JSON#simple-scalars
+        # numify it, ensuring it will be dumped as a number
+        return $data + 0;
+    } elsif ($type eq 'string') {
+        # https://metacpan.org/pod/JSON#simple-scalars
+        # stringified
+        return $data . q();
+    } elsif ($type eq 'boolean') {
+        # https://metacpan.org/pod/JSON#JSON::true,-JSON::false,-JSON::null
+        return $data ? \1 : \0;
+    } elsif ($type eq 'DATE') {
+        if (ref($data) eq 'DateTime') {
+            # https://metacpan.org/pod/DateTime#$dt-%3Eymd($optional_separator),-$dt-%3Emdy(...),-$dt-%3Edmy(...)
+            return $data->ymd;
+        }
+        return $data .q();
+    } elsif ($type eq 'DATE_TIME') {
+        # the date-time notation as defined by RFC 3339, section 5.6, for example, 2017-07-21T17:32:28Z
+        if (ref($data) eq 'DateTime') {
+            # https://metacpan.org/pod/DateTime#$dt-%3Erfc3339
+            return $data->rfc3339;
+        }
+        return $data .q();
+    }
+}
+
 # from Perl hashref
 sub from_hash {
    my ($self, $hash) = @_;
@@ -147,10 +194,14 @@ sub _deserialize {
    my ($self, $type, $data) = @_;
    $log->debugf("deserializing %s with %s",Dumper($data), $type);

-    if ($type eq 'DateTime') {
+    if (grep( /^$type$/ , ('DATE_TIME', 'DATE'))) {
        return DateTime->from_epoch(epoch => str2time($data));
-    } elsif ( grep( /^$type$/, ('int', 'double', 'string', 'boolean'))) {
-        return $data;
+    } elsif ( grep( /^$type$/, ('int', 'double'))) {
+        return $data + 0;
+    } elsif ($type eq 'string') {
+        return $data . q();
+    } elsif ($type eq 'boolean') {
+        return !!$data;
    } else { # hash(model)
        my $_instance = eval "WWW::OpenAPIClient::Object::$type->new()";
        return $_instance->from_hash($data);
--- a/samples/client/petstore/perl/lib/WWW/OpenAPIClient/Object/File.pm
+++ b/samples/client/petstore/perl/lib/WWW/OpenAPIClient/Object/File.pm
@@ -100,13 +100,60 @@ sub TO_JSON {
    my $_data = {};
    foreach my $_key (keys %{$self->attribute_map}) {
        if (defined $self->{$_key}) {
-            $_data->{$self->attribute_map->{$_key}} = $self->{$_key};
+            my $_json_attribute = $self->attribute_map->{$_key};
+            my $_type = $self->openapi_types->{$_key};
+            my $_value = $self->{$_key};
+            if ($_type =~ /^array\[(.+)\]$/i) { # array
+                my $_subclass = $1;
+                $_data->{$_json_attribute} =  [ map { $self->_to_json_primitives($_subclass, $_) } @$_value ];
+            } elsif ($_type =~ /^hash\[string,(.+)\]$/i) { # hash
+                my $_subclass = $1;
+                my %_hash = ();
+                while (my($_key, $_element) = each %{$_value}) {
+                    $_hash{$_key} = $self->_to_json_primitives($_subclass, $_element);
+                }
+                $_data->{$_json_attribute} = \%_hash;
+            } elsif ( grep( /^$_type$/, ('int', 'double', 'string', 'boolean', 'DATE', 'DATE_TIME'))) {
+                $_data->{$_json_attribute} = $self->_to_json_primitives($_type, $_value);
+            } else {
+                $_data->{$_json_attribute} = $_value;
+            }
        }
    }

    return $_data;
 }

+# to_json non-array data
+sub _to_json_primitives {
+    my ($self, $type, $data) = @_;
+    if ( grep( /^$type$/, ('int', 'double'))) {
+        # https://metacpan.org/pod/JSON#simple-scalars
+        # numify it, ensuring it will be dumped as a number
+        return $data + 0;
+    } elsif ($type eq 'string') {
+        # https://metacpan.org/pod/JSON#simple-scalars
+        # stringified
+        return $data . q();
+    } elsif ($type eq 'boolean') {
+        # https://metacpan.org/pod/JSON#JSON::true,-JSON::false,-JSON::null
+        return $data ? \1 : \0;
+    } elsif ($type eq 'DATE') {
+        if (ref($data) eq 'DateTime') {
+            # https://metacpan.org/pod/DateTime#$dt-%3Eymd($optional_separator),-$dt-%3Emdy(...),-$dt-%3Edmy(...)
+            return $data->ymd;
+        }
+        return $data .q();
+    } elsif ($type eq 'DATE_TIME') {
+        # the date-time notation as defined by RFC 3339, section 5.6, for example, 2017-07-21T17:32:28Z
+        if (ref($data) eq 'DateTime') {
+            # https://metacpan.org/pod/DateTime#$dt-%3Erfc3339
+            return $data->rfc3339;
+        }
+        return $data .q();
+    }
+}
+
 # from Perl hashref
 sub from_hash {
    my ($self, $hash) = @_;
@@ -143,10 +190,14 @@ sub _deserialize {
    my ($self, $type, $data) = @_;
    $log->debugf("deserializing %s with %s",Dumper($data), $type);

-    if ($type eq 'DateTime') {
+    if (grep( /^$type$/ , ('DATE_TIME', 'DATE'))) {
        return DateTime->from_epoch(epoch => str2time($data));
-    } elsif ( grep( /^$type$/, ('int', 'double', 'string', 'boolean'))) {
-        return $data;
+    } elsif ( grep( /^$type$/, ('int', 'double'))) {
+        return $data + 0;
+    } elsif ($type eq 'string') {
+        return $data . q();
+    } elsif ($type eq 'boolean') {
+        return !!$data;
    } else { # hash(model)
        my $_instance = eval "WWW::OpenAPIClient::Object::$type->new()";
        return $_instance->from_hash($data);
--- a/samples/client/petstore/perl/lib/WWW/OpenAPIClient/Object/FileSchemaTestClass.pm
+++ b/samples/client/petstore/perl/lib/WWW/OpenAPIClient/Object/FileSchemaTestClass.pm
@@ -101,13 +101,60 @@ sub TO_JSON {
    my $_data = {};
    foreach my $_key (keys %{$self->attribute_map}) {
        if (defined $self->{$_key}) {
-            $_data->{$self->attribute_map->{$_key}} = $self->{$_key};
+            my $_json_attribute = $self->attribute_map->{$_key};
+            my $_type = $self->openapi_types->{$_key};
+            my $_value = $self->{$_key};
+            if ($_type =~ /^array\[(.+)\]$/i) { # array
+                my $_subclass = $1;
+                $_data->{$_json_attribute} =  [ map { $self->_to_json_primitives($_subclass, $_) } @$_value ];
+            } elsif ($_type =~ /^hash\[string,(.+)\]$/i) { # hash
+                my $_subclass = $1;
+                my %_hash = ();
+                while (my($_key, $_element) = each %{$_value}) {
+                    $_hash{$_key} = $self->_to_json_primitives($_subclass, $_element);
+                }
+                $_data->{$_json_attribute} = \%_hash;
+            } elsif ( grep( /^$_type$/, ('int', 'double', 'string', 'boolean', 'DATE', 'DATE_TIME'))) {
+                $_data->{$_json_attribute} = $self->_to_json_primitives($_type, $_value);
+            } else {
+                $_data->{$_json_attribute} = $_value;
+            }
        }
    }

    return $_data;
 }

+# to_json non-array data
+sub _to_json_primitives {
+    my ($self, $type, $data) = @_;
+    if ( grep( /^$type$/, ('int', 'double'))) {
+        # https://metacpan.org/pod/JSON#simple-scalars
+        # numify it, ensuring it will be dumped as a number
+        return $data + 0;
+    } elsif ($type eq 'string') {
+        # https://metacpan.org/pod/JSON#simple-scalars
+        # stringified
+        return $data . q();
+    } elsif ($type eq 'boolean') {
+        # https://metacpan.org/pod/JSON#JSON::true,-JSON::false,-JSON::null
+        return $data ? \1 : \0;
+    } elsif ($type eq 'DATE') {
+        if (ref($data) eq 'DateTime') {
+            # https://metacpan.org/pod/DateTime#$dt-%3Eymd($optional_separator),-$dt-%3Emdy(...),-$dt-%3Edmy(...)
+            return $data->ymd;
+        }
+        return $data .q();
+    } elsif ($type eq 'DATE_TIME') {
+        # the date-time notation as defined by RFC 3339, section 5.6, for example, 2017-07-21T17:32:28Z
+        if (ref($data) eq 'DateTime') {
+            # https://metacpan.org/pod/DateTime#$dt-%3Erfc3339
+            return $data->rfc3339;
+        }
+        return $data .q();
+    }
+}
+
 # from Perl hashref
 sub from_hash {
    my ($self, $hash) = @_;
@@ -144,10 +191,14 @@ sub _deserialize {
    my ($self, $type, $data) = @_;
    $log->debugf("deserializing %s with %s",Dumper($data), $type);

-    if ($type eq 'DateTime') {
+    if (grep( /^$type$/ , ('DATE_TIME', 'DATE'))) {
        return DateTime->from_epoch(epoch => str2time($data));
-    } elsif ( grep( /^$type$/, ('int', 'double', 'string', 'boolean'))) {
-        return $data;
+    } elsif ( grep( /^$type$/, ('int', 'double'))) {
+        return $data + 0;
+    } elsif ($type eq 'string') {
+        return $data . q();
+    } elsif ($type eq 'boolean') {
+        return !!$data;
    } else { # hash(model)
        my $_instance = eval "WWW::OpenAPIClient::Object::$type->new()";
        return $_instance->from_hash($data);
--- a/samples/client/petstore/perl/lib/WWW/OpenAPIClient/Object/Foo.pm
+++ b/samples/client/petstore/perl/lib/WWW/OpenAPIClient/Object/Foo.pm
@@ -100,13 +100,60 @@ sub TO_JSON {
    my $_data = {};
    foreach my $_key (keys %{$self->attribute_map}) {
        if (defined $self->{$_key}) {
-            $_data->{$self->attribute_map->{$_key}} = $self->{$_key};
+            my $_json_attribute = $self->attribute_map->{$_key};
+            my $_type = $self->openapi_types->{$_key};
+            my $_value = $self->{$_key};
+            if ($_type =~ /^array\[(.+)\]$/i) { # array
+                my $_subclass = $1;
+                $_data->{$_json_attribute} =  [ map { $self->_to_json_primitives($_subclass, $_) } @$_value ];
+            } elsif ($_type =~ /^hash\[string,(.+)\]$/i) { # hash
+                my $_subclass = $1;
+                my %_hash = ();
+                while (my($_key, $_element) = each %{$_value}) {
+                    $_hash{$_key} = $self->_to_json_primitives($_subclass, $_element);
+                }
+                $_data->{$_json_attribute} = \%_hash;
+            } elsif ( grep( /^$_type$/, ('int', 'double', 'string', 'boolean', 'DATE', 'DATE_TIME'))) {
+                $_data->{$_json_attribute} = $self->_to_json_primitives($_type, $_value);
+            } else {
+                $_data->{$_json_attribute} = $_value;
+            }
        }
    }

    return $_data;
 }

+# to_json non-array data
+sub _to_json_primitives {
+    my ($self, $type, $data) = @_;
+    if ( grep( /^$type$/, ('int', 'double'))) {
+        # https://metacpan.org/pod/JSON#simple-scalars
+        # numify it, ensuring it will be dumped as a number
+        return $data + 0;
+    } elsif ($type eq 'string') {
+        # https://metacpan.org/pod/JSON#simple-scalars
+        # stringified
+        return $data . q();
+    } elsif ($type eq 'boolean') {
+        # https://metacpan.org/pod/JSON#JSON::true,-JSON::false,-JSON::null
+        return $data ? \1 : \0;
+    } elsif ($type eq 'DATE') {
+        if (ref($data) eq 'DateTime') {
+            # https://metacpan.org/pod/DateTime#$dt-%3Eymd($optional_separator),-$dt-%3Emdy(...),-$dt-%3Edmy(...)
+            return $data->ymd;
+        }
+        return $data .q();
+    } elsif ($type eq 'DATE_TIME') {
+        # the date-time notation as defined by RFC 3339, section 5.6, for example, 2017-07-21T17:32:28Z
+        if (ref($data) eq 'DateTime') {
+            # https://metacpan.org/pod/DateTime#$dt-%3Erfc3339
+            return $data->rfc3339;
+        }
+        return $data .q();
+    }
+}
+
 # from Perl hashref
 sub from_hash {
    my ($self, $hash) = @_;
@@ -143,10 +190,14 @@ sub _deserialize {
    my ($self, $type, $data) = @_;
    $log->debugf("deserializing %s with %s",Dumper($data), $type);

-    if ($type eq 'DateTime') {
+    if (grep( /^$type$/ , ('DATE_TIME', 'DATE'))) {
        return DateTime->from_epoch(epoch => str2time($data));
-    } elsif ( grep( /^$type$/, ('int', 'double', 'string', 'boolean'))) {
-        return $data;
+    } elsif ( grep( /^$type$/, ('int', 'double'))) {
+        return $data + 0;
+    } elsif ($type eq 'string') {
+        return $data . q();
+    } elsif ($type eq 'boolean') {
+        return !!$data;
    } else { # hash(model)
        my $_instance = eval "WWW::OpenAPIClient::Object::$type->new()";
        return $_instance->from_hash($data);
--- a/samples/client/petstore/perl/lib/WWW/OpenAPIClient/Object/FooGetDefaultResponse.pm
+++ b/samples/client/petstore/perl/lib/WWW/OpenAPIClient/Object/FooGetDefaultResponse.pm
@@ -101,13 +101,60 @@ sub TO_JSON {
    my $_data = {};
    foreach my $_key (keys %{$self->attribute_map}) {
        if (defined $self->{$_key}) {
-            $_data->{$self->attribute_map->{$_key}} = $self->{$_key};
+            my $_json_attribute = $self->attribute_map->{$_key};
+            my $_type = $self->openapi_types->{$_key};
+            my $_value = $self->{$_key};
+            if ($_type =~ /^array\[(.+)\]$/i) { # array
+                my $_subclass = $1;
+                $_data->{$_json_attribute} =  [ map { $self->_to_json_primitives($_subclass, $_) } @$_value ];
+            } elsif ($_type =~ /^hash\[string,(.+)\]$/i) { # hash
+                my $_subclass = $1;
+                my %_hash = ();
+                while (my($_key, $_element) = each %{$_value}) {
+                    $_hash{$_key} = $self->_to_json_primitives($_subclass, $_element);
+                }
+                $_data->{$_json_attribute} = \%_hash;
+            } elsif ( grep( /^$_type$/, ('int', 'double', 'string', 'boolean', 'DATE', 'DATE_TIME'))) {
+                $_data->{$_json_attribute} = $self->_to_json_primitives($_type, $_value);
+            } else {
+                $_data->{$_json_attribute} = $_value;
+            }
        }
    }

    return $_data;
 }

+# to_json non-array data
+sub _to_json_primitives {
+    my ($self, $type, $data) = @_;
+    if ( grep( /^$type$/, ('int', 'double'))) {
+        # https://metacpan.org/pod/JSON#simple-scalars
+        # numify it, ensuring it will be dumped as a number
+        return $data + 0;
+    } elsif ($type eq 'string') {
+        # https://metacpan.org/pod/JSON#simple-scalars
+        # stringified
+        return $data . q();
+    } elsif ($type eq 'boolean') {
+        # https://metacpan.org/pod/JSON#JSON::true,-JSON::false,-JSON::null
+        return $data ? \1 : \0;
+    } elsif ($type eq 'DATE') {
+        if (ref($data) eq 'DateTime') {
+            # https://metacpan.org/pod/DateTime#$dt-%3Eymd($optional_separator),-$dt-%3Emdy(...),-$dt-%3Edmy(...)
+            return $data->ymd;
+        }
+        return $data .q();
+    } elsif ($type eq 'DATE_TIME') {
+        # the date-time notation as defined by RFC 3339, section 5.6, for example, 2017-07-21T17:32:28Z
+        if (ref($data) eq 'DateTime') {
+            # https://metacpan.org/pod/DateTime#$dt-%3Erfc3339
+            return $data->rfc3339;
+        }
+        return $data .q();
+    }
+}
+
 # from Perl hashref
 sub from_hash {
    my ($self, $hash) = @_;
@@ -144,10 +191,14 @@ sub _deserialize {
    my ($self, $type, $data) = @_;
    $log->debugf("deserializing %s with %s",Dumper($data), $type);

-    if ($type eq 'DateTime') {
+    if (grep( /^$type$/ , ('DATE_TIME', 'DATE'))) {
        return DateTime->from_epoch(epoch => str2time($data));
-    } elsif ( grep( /^$type$/, ('int', 'double', 'string', 'boolean'))) {
-        return $data;
+    } elsif ( grep( /^$type$/, ('int', 'double'))) {
+        return $data + 0;
+    } elsif ($type eq 'string') {
+        return $data . q();
+    } elsif ($type eq 'boolean') {
+        return !!$data;
    } else { # hash(model)
        my $_instance = eval "WWW::OpenAPIClient::Object::$type->new()";
        return $_instance->from_hash($data);
--- a/samples/client/petstore/perl/lib/WWW/OpenAPIClient/Object/FormatTest.pm
+++ b/samples/client/petstore/perl/lib/WWW/OpenAPIClient/Object/FormatTest.pm
@@ -101,13 +101,60 @@ sub TO_JSON {
    my $_data = {};
    foreach my $_key (keys %{$self->attribute_map}) {
        if (defined $self->{$_key}) {
-            $_data->{$self->attribute_map->{$_key}} = $self->{$_key};
+            my $_json_attribute = $self->attribute_map->{$_key};
+            my $_type = $self->openapi_types->{$_key};
+            my $_value = $self->{$_key};
+            if ($_type =~ /^array\[(.+)\]$/i) { # array
+                my $_subclass = $1;
+                $_data->{$_json_attribute} =  [ map { $self->_to_json_primitives($_subclass, $_) } @$_value ];
+            } elsif ($_type =~ /^hash\[string,(.+)\]$/i) { # hash
+                my $_subclass = $1;
+                my %_hash = ();
+                while (my($_key, $_element) = each %{$_value}) {
+                    $_hash{$_key} = $self->_to_json_primitives($_subclass, $_element);
+                }
+                $_data->{$_json_attribute} = \%_hash;
+            } elsif ( grep( /^$_type$/, ('int', 'double', 'string', 'boolean', 'DATE', 'DATE_TIME'))) {
+                $_data->{$_json_attribute} = $self->_to_json_primitives($_type, $_value);
+            } else {
+                $_data->{$_json_attribute} = $_value;
+            }
        }
    }

    return $_data;
 }

+# to_json non-array data
+sub _to_json_primitives {
+    my ($self, $type, $data) = @_;
+    if ( grep( /^$type$/, ('int', 'double'))) {
+        # https://metacpan.org/pod/JSON#simple-scalars
+        # numify it, ensuring it will be dumped as a number
+        return $data + 0;
+    } elsif ($type eq 'string') {
+        # https://metacpan.org/pod/JSON#simple-scalars
+        # stringified
+        return $data . q();
+    } elsif ($type eq 'boolean') {
+        # https://metacpan.org/pod/JSON#JSON::true,-JSON::false,-JSON::null
+        return $data ? \1 : \0;
+    } elsif ($type eq 'DATE') {
+        if (ref($data) eq 'DateTime') {
+            # https://metacpan.org/pod/DateTime#$dt-%3Eymd($optional_separator),-$dt-%3Emdy(...),-$dt-%3Edmy(...)
+            return $data->ymd;
+        }
+        return $data .q();
+    } elsif ($type eq 'DATE_TIME') {
+        # the date-time notation as defined by RFC 3339, section 5.6, for example, 2017-07-21T17:32:28Z
+        if (ref($data) eq 'DateTime') {
+            # https://metacpan.org/pod/DateTime#$dt-%3Erfc3339
+            return $data->rfc3339;
+        }
+        return $data .q();
+    }
+}
+
 # from Perl hashref
 sub from_hash {
    my ($self, $hash) = @_;
@@ -144,10 +191,14 @@ sub _deserialize {
    my ($self, $type, $data) = @_;
    $log->debugf("deserializing %s with %s",Dumper($data), $type);

-    if ($type eq 'DateTime') {
+    if (grep( /^$type$/ , ('DATE_TIME', 'DATE'))) {
        return DateTime->from_epoch(epoch => str2time($data));
-    } elsif ( grep( /^$type$/, ('int', 'double', 'string', 'boolean'))) {
-        return $data;
+    } elsif ( grep( /^$type$/, ('int', 'double'))) {
+        return $data + 0;
+    } elsif ($type eq 'string') {
+        return $data . q();
+    } elsif ($type eq 'boolean') {
+        return !!$data;
    } else { # hash(model)
        my $_instance = eval "WWW::OpenAPIClient::Object::$type->new()";
        return $_instance->from_hash($data);
@@ -232,14 +283,14 @@ __PACKAGE__->method_documentation({
        read_only => '',
            },
    'date' => {
-        datatype => 'DateTime',
+        datatype => 'DATE',
        base_name => 'date',
        description => '',
        format => '',
        read_only => '',
            },
    'date_time' => {
-        datatype => 'DateTime',
+        datatype => 'DATE_TIME',
        base_name => 'dateTime',
        description => '',
        format => '',
@@ -286,8 +337,8 @@ __PACKAGE__->openapi_types( {
    'string' => 'string',
    'byte' => 'string',
    'binary' => 'string',
-    'date' => 'DateTime',
-    'date_time' => 'DateTime',
+    'date' => 'DATE',
+    'date_time' => 'DATE_TIME',
    'uuid' => 'string',
    'password' => 'string',
    'pattern_with_digits' => 'string',
--- a/samples/client/petstore/perl/lib/WWW/OpenAPIClient/Object/HasOnlyReadOnly.pm
+++ b/samples/client/petstore/perl/lib/WWW/OpenAPIClient/Object/HasOnlyReadOnly.pm
@@ -100,13 +100,60 @@ sub TO_JSON {
    my $_data = {};
    foreach my $_key (keys %{$self->attribute_map}) {
        if (defined $self->{$_key}) {
-            $_data->{$self->attribute_map->{$_key}} = $self->{$_key};
+            my $_json_attribute = $self->attribute_map->{$_key};
+            my $_type = $self->openapi_types->{$_key};
+            my $_value = $self->{$_key};
+            if ($_type =~ /^array\[(.+)\]$/i) { # array
+                my $_subclass = $1;
+                $_data->{$_json_attribute} =  [ map { $self->_to_json_primitives($_subclass, $_) } @$_value ];
+            } elsif ($_type =~ /^hash\[string,(.+)\]$/i) { # hash
+                my $_subclass = $1;
+                my %_hash = ();
+                while (my($_key, $_element) = each %{$_value}) {
+                    $_hash{$_key} = $self->_to_json_primitives($_subclass, $_element);
+                }
+                $_data->{$_json_attribute} = \%_hash;
+            } elsif ( grep( /^$_type$/, ('int', 'double', 'string', 'boolean', 'DATE', 'DATE_TIME'))) {
+                $_data->{$_json_attribute} = $self->_to_json_primitives($_type, $_value);
+            } else {
+                $_data->{$_json_attribute} = $_value;
+            }
        }
    }

    return $_data;
 }

+# to_json non-array data
+sub _to_json_primitives {
+    my ($self, $type, $data) = @_;
+    if ( grep( /^$type$/, ('int', 'double'))) {
+        # https://metacpan.org/pod/JSON#simple-scalars
+        # numify it, ensuring it will be dumped as a number
+        return $data + 0;
+    } elsif ($type eq 'string') {
+        # https://metacpan.org/pod/JSON#simple-scalars
+        # stringified
+        return $data . q();
+    } elsif ($type eq 'boolean') {
+        # https://metacpan.org/pod/JSON#JSON::true,-JSON::false,-JSON::null
+        return $data ? \1 : \0;
+    } elsif ($type eq 'DATE') {
+        if (ref($data) eq 'DateTime') {
+            # https://metacpan.org/pod/DateTime#$dt-%3Eymd($optional_separator),-$dt-%3Emdy(...),-$dt-%3Edmy(...)
+            return $data->ymd;
+        }
+        return $data .q();
+    } elsif ($type eq 'DATE_TIME') {
+        # the date-time notation as defined by RFC 3339, section 5.6, for example, 2017-07-21T17:32:28Z
+        if (ref($data) eq 'DateTime') {
+            # https://metacpan.org/pod/DateTime#$dt-%3Erfc3339
+            return $data->rfc3339;
+        }
+        return $data .q();
+    }
+}
+
 # from Perl hashref
 sub from_hash {
    my ($self, $hash) = @_;
@@ -143,10 +190,14 @@ sub _deserialize {
    my ($self, $type, $data) = @_;
    $log->debugf("deserializing %s with %s",Dumper($data), $type);

-    if ($type eq 'DateTime') {
+    if (grep( /^$type$/ , ('DATE_TIME', 'DATE'))) {
        return DateTime->from_epoch(epoch => str2time($data));
-    } elsif ( grep( /^$type$/, ('int', 'double', 'string', 'boolean'))) {
-        return $data;
+    } elsif ( grep( /^$type$/, ('int', 'double'))) {
+        return $data + 0;
+    } elsif ($type eq 'string') {
+        return $data . q();
+    } elsif ($type eq 'boolean') {
+        return !!$data;
    } else { # hash(model)
        my $_instance = eval "WWW::OpenAPIClient::Object::$type->new()";
        return $_instance->from_hash($data);
--- a/samples/client/petstore/perl/lib/WWW/OpenAPIClient/Object/HealthCheckResult.pm
+++ b/samples/client/petstore/perl/lib/WWW/OpenAPIClient/Object/HealthCheckResult.pm
@@ -100,13 +100,60 @@ sub TO_JSON {
    my $_data = {};
    foreach my $_key (keys %{$self->attribute_map}) {
        if (defined $self->{$_key}) {
-            $_data->{$self->attribute_map->{$_key}} = $self->{$_key};
+            my $_json_attribute = $self->attribute_map->{$_key};
+            my $_type = $self->openapi_types->{$_key};
+            my $_value = $self->{$_key};
+            if ($_type =~ /^array\[(.+)\]$/i) { # array
+                my $_subclass = $1;
+                $_data->{$_json_attribute} =  [ map { $self->_to_json_primitives($_subclass, $_) } @$_value ];
+            } elsif ($_type =~ /^hash\[string,(.+)\]$/i) { # hash
+                my $_subclass = $1;
+                my %_hash = ();
+                while (my($_key, $_element) = each %{$_value}) {
+                    $_hash{$_key} = $self->_to_json_primitives($_subclass, $_element);
+                }
+                $_data->{$_json_attribute} = \%_hash;
+            } elsif ( grep( /^$_type$/, ('int', 'double', 'string', 'boolean', 'DATE', 'DATE_TIME'))) {
+                $_data->{$_json_attribute} = $self->_to_json_primitives($_type, $_value);
+            } else {
+                $_data->{$_json_attribute} = $_value;
+            }
        }
    }

    return $_data;
 }

+# to_json non-array data
+sub _to_json_primitives {
+    my ($self, $type, $data) = @_;
+    if ( grep( /^$type$/, ('int', 'double'))) {
+        # https://metacpan.org/pod/JSON#simple-scalars
+        # numify it, ensuring it will be dumped as a number
+        return $data + 0;
+    } elsif ($type eq 'string') {
+        # https://metacpan.org/pod/JSON#simple-scalars
+        # stringified
+        return $data . q();
+    } elsif ($type eq 'boolean') {
+        # https://metacpan.org/pod/JSON#JSON::true,-JSON::false,-JSON::null
+        return $data ? \1 : \0;
+    } elsif ($type eq 'DATE') {
+        if (ref($data) eq 'DateTime') {
+            # https://metacpan.org/pod/DateTime#$dt-%3Eymd($optional_separator),-$dt-%3Emdy(...),-$dt-%3Edmy(...)
+            return $data->ymd;
+        }
+        return $data .q();
+    } elsif ($type eq 'DATE_TIME') {
+        # the date-time notation as defined by RFC 3339, section 5.6, for example, 2017-07-21T17:32:28Z
+        if (ref($data) eq 'DateTime') {
+            # https://metacpan.org/pod/DateTime#$dt-%3Erfc3339
+            return $data->rfc3339;
+        }
+        return $data .q();
+    }
+}
+
 # from Perl hashref
 sub from_hash {
    my ($self, $hash) = @_;
@@ -143,10 +190,14 @@ sub _deserialize {
    my ($self, $type, $data) = @_;
    $log->debugf("deserializing %s with %s",Dumper($data), $type);

-    if ($type eq 'DateTime') {
+    if (grep( /^$type$/ , ('DATE_TIME', 'DATE'))) {
        return DateTime->from_epoch(epoch => str2time($data));
-    } elsif ( grep( /^$type$/, ('int', 'double', 'string', 'boolean'))) {
-        return $data;
+    } elsif ( grep( /^$type$/, ('int', 'double'))) {
+        return $data + 0;
+    } elsif ($type eq 'string') {
+        return $data . q();
+    } elsif ($type eq 'boolean') {
+        return !!$data;
    } else { # hash(model)
        my $_instance = eval "WWW::OpenAPIClient::Object::$type->new()";
        return $_instance->from_hash($data);
--- a/samples/client/petstore/perl/lib/WWW/OpenAPIClient/Object/List.pm
+++ b/samples/client/petstore/perl/lib/WWW/OpenAPIClient/Object/List.pm
@@ -100,13 +100,60 @@ sub TO_JSON {
    my $_data = {};
    foreach my $_key (keys %{$self->attribute_map}) {
        if (defined $self->{$_key}) {
-            $_data->{$self->attribute_map->{$_key}} = $self->{$_key};
+            my $_json_attribute = $self->attribute_map->{$_key};
+            my $_type = $self->openapi_types->{$_key};
+            my $_value = $self->{$_key};
+            if ($_type =~ /^array\[(.+)\]$/i) { # array
+                my $_subclass = $1;
+                $_data->{$_json_attribute} =  [ map { $self->_to_json_primitives($_subclass, $_) } @$_value ];
+            } elsif ($_type =~ /^hash\[string,(.+)\]$/i) { # hash
+                my $_subclass = $1;
+                my %_hash = ();
+                while (my($_key, $_element) = each %{$_value}) {
+                    $_hash{$_key} = $self->_to_json_primitives($_subclass, $_element);
+                }
+                $_data->{$_json_attribute} = \%_hash;
+            } elsif ( grep( /^$_type$/, ('int', 'double', 'string', 'boolean', 'DATE', 'DATE_TIME'))) {
+                $_data->{$_json_attribute} = $self->_to_json_primitives($_type, $_value);
+            } else {
+                $_data->{$_json_attribute} = $_value;
+            }
        }
    }

    return $_data;
 }

+# to_json non-array data
+sub _to_json_primitives {
+    my ($self, $type, $data) = @_;
+    if ( grep( /^$type$/, ('int', 'double'))) {
+        # https://metacpan.org/pod/JSON#simple-scalars
+        # numify it, ensuring it will be dumped as a number
+        return $data + 0;
+    } elsif ($type eq 'string') {
+        # https://metacpan.org/pod/JSON#simple-scalars
+        # stringified
+        return $data . q();
+    } elsif ($type eq 'boolean') {
+        # https://metacpan.org/pod/JSON#JSON::true,-JSON::false,-JSON::null
+        return $data ? \1 : \0;
+    } elsif ($type eq 'DATE') {
+        if (ref($data) eq 'DateTime') {
+            # https://metacpan.org/pod/DateTime#$dt-%3Eymd($optional_separator),-$dt-%3Emdy(...),-$dt-%3Edmy(...)
+            return $data->ymd;
+        }
+        return $data .q();
+    } elsif ($type eq 'DATE_TIME') {
+        # the date-time notation as defined by RFC 3339, section 5.6, for example, 2017-07-21T17:32:28Z
+        if (ref($data) eq 'DateTime') {
+            # https://metacpan.org/pod/DateTime#$dt-%3Erfc3339
+            return $data->rfc3339;
+        }
+        return $data .q();
+    }
+}
+
 # from Perl hashref
 sub from_hash {
    my ($self, $hash) = @_;
@@ -143,10 +190,14 @@ sub _deserialize {
    my ($self, $type, $data) = @_;
    $log->debugf("deserializing %s with %s",Dumper($data), $type);

-    if ($type eq 'DateTime') {
+    if (grep( /^$type$/ , ('DATE_TIME', 'DATE'))) {
        return DateTime->from_epoch(epoch => str2time($data));
-    } elsif ( grep( /^$type$/, ('int', 'double', 'string', 'boolean'))) {
-        return $data;
+    } elsif ( grep( /^$type$/, ('int', 'double'))) {
+        return $data + 0;
+    } elsif ($type eq 'string') {
+        return $data . q();
+    } elsif ($type eq 'boolean') {
+        return !!$data;
    } else { # hash(model)
        my $_instance = eval "WWW::OpenAPIClient::Object::$type->new()";
        return $_instance->from_hash($data);
--- a/samples/client/petstore/perl/lib/WWW/OpenAPIClient/Object/MapTest.pm
+++ b/samples/client/petstore/perl/lib/WWW/OpenAPIClient/Object/MapTest.pm
@@ -100,13 +100,60 @@ sub TO_JSON {
    my $_data = {};
    foreach my $_key (keys %{$self->attribute_map}) {
        if (defined $self->{$_key}) {
-            $_data->{$self->attribute_map->{$_key}} = $self->{$_key};
+            my $_json_attribute = $self->attribute_map->{$_key};
+            my $_type = $self->openapi_types->{$_key};
+            my $_value = $self->{$_key};
+            if ($_type =~ /^array\[(.+)\]$/i) { # array
+                my $_subclass = $1;
+                $_data->{$_json_attribute} =  [ map { $self->_to_json_primitives($_subclass, $_) } @$_value ];
+            } elsif ($_type =~ /^hash\[string,(.+)\]$/i) { # hash
+                my $_subclass = $1;
+                my %_hash = ();
+                while (my($_key, $_element) = each %{$_value}) {
+                    $_hash{$_key} = $self->_to_json_primitives($_subclass, $_element);
+                }
+                $_data->{$_json_attribute} = \%_hash;
+            } elsif ( grep( /^$_type$/, ('int', 'double', 'string', 'boolean', 'DATE', 'DATE_TIME'))) {
+                $_data->{$_json_attribute} = $self->_to_json_primitives($_type, $_value);
+            } else {
+                $_data->{$_json_attribute} = $_value;
+            }
        }
    }

    return $_data;
 }

+# to_json non-array data
+sub _to_json_primitives {
+    my ($self, $type, $data) = @_;
+    if ( grep( /^$type$/, ('int', 'double'))) {
+        # https://metacpan.org/pod/JSON#simple-scalars
+        # numify it, ensuring it will be dumped as a number
+        return $data + 0;
+    } elsif ($type eq 'string') {
+        # https://metacpan.org/pod/JSON#simple-scalars
+        # stringified
+        return $data . q();
+    } elsif ($type eq 'boolean') {
+        # https://metacpan.org/pod/JSON#JSON::true,-JSON::false,-JSON::null
+        return $data ? \1 : \0;
+    } elsif ($type eq 'DATE') {
+        if (ref($data) eq 'DateTime') {
+            # https://metacpan.org/pod/DateTime#$dt-%3Eymd($optional_separator),-$dt-%3Emdy(...),-$dt-%3Edmy(...)
+            return $data->ymd;
+        }
+        return $data .q();
+    } elsif ($type eq 'DATE_TIME') {
+        # the date-time notation as defined by RFC 3339, section 5.6, for example, 2017-07-21T17:32:28Z
+        if (ref($data) eq 'DateTime') {
+            # https://metacpan.org/pod/DateTime#$dt-%3Erfc3339
+            return $data->rfc3339;
+        }
+        return $data .q();
+    }
+}
+
 # from Perl hashref
 sub from_hash {
    my ($self, $hash) = @_;
@@ -143,10 +190,14 @@ sub _deserialize {
    my ($self, $type, $data) = @_;
    $log->debugf("deserializing %s with %s",Dumper($data), $type);

-    if ($type eq 'DateTime') {
+    if (grep( /^$type$/ , ('DATE_TIME', 'DATE'))) {
        return DateTime->from_epoch(epoch => str2time($data));
-    } elsif ( grep( /^$type$/, ('int', 'double', 'string', 'boolean'))) {
-        return $data;
+    } elsif ( grep( /^$type$/, ('int', 'double'))) {
+        return $data + 0;
+    } elsif ($type eq 'string') {
+        return $data . q();
+    } elsif ($type eq 'boolean') {
+        return !!$data;
    } else { # hash(model)
        my $_instance = eval "WWW::OpenAPIClient::Object::$type->new()";
        return $_instance->from_hash($data);
--- a/samples/client/petstore/perl/lib/WWW/OpenAPIClient/Object/MixedPropertiesAndAdditionalPropertiesClass.pm
+++ b/samples/client/petstore/perl/lib/WWW/OpenAPIClient/Object/MixedPropertiesAndAdditionalPropertiesClass.pm
@@ -101,13 +101,60 @@ sub TO_JSON {
    my $_data = {};
    foreach my $_key (keys %{$self->attribute_map}) {
        if (defined $self->{$_key}) {
-            $_data->{$self->attribute_map->{$_key}} = $self->{$_key};
+            my $_json_attribute = $self->attribute_map->{$_key};
+            my $_type = $self->openapi_types->{$_key};
+            my $_value = $self->{$_key};
+            if ($_type =~ /^array\[(.+)\]$/i) { # array
+                my $_subclass = $1;
+                $_data->{$_json_attribute} =  [ map { $self->_to_json_primitives($_subclass, $_) } @$_value ];
+            } elsif ($_type =~ /^hash\[string,(.+)\]$/i) { # hash
+                my $_subclass = $1;
+                my %_hash = ();
+                while (my($_key, $_element) = each %{$_value}) {
+                    $_hash{$_key} = $self->_to_json_primitives($_subclass, $_element);
+                }
+                $_data->{$_json_attribute} = \%_hash;
+            } elsif ( grep( /^$_type$/, ('int', 'double', 'string', 'boolean', 'DATE', 'DATE_TIME'))) {
+                $_data->{$_json_attribute} = $self->_to_json_primitives($_type, $_value);
+            } else {
+                $_data->{$_json_attribute} = $_value;
+            }
        }
    }

    return $_data;
 }

+# to_json non-array data
+sub _to_json_primitives {
+    my ($self, $type, $data) = @_;
+    if ( grep( /^$type$/, ('int', 'double'))) {
+        # https://metacpan.org/pod/JSON#simple-scalars
+        # numify it, ensuring it will be dumped as a number
+        return $data + 0;
+    } elsif ($type eq 'string') {
+        # https://metacpan.org/pod/JSON#simple-scalars
+        # stringified
+        return $data . q();
+    } elsif ($type eq 'boolean') {
+        # https://metacpan.org/pod/JSON#JSON::true,-JSON::false,-JSON::null
+        return $data ? \1 : \0;
+    } elsif ($type eq 'DATE') {
+        if (ref($data) eq 'DateTime') {
+            # https://metacpan.org/pod/DateTime#$dt-%3Eymd($optional_separator),-$dt-%3Emdy(...),-$dt-%3Edmy(...)
+            return $data->ymd;
+        }
+        return $data .q();
+    } elsif ($type eq 'DATE_TIME') {
+        # the date-time notation as defined by RFC 3339, section 5.6, for example, 2017-07-21T17:32:28Z
+        if (ref($data) eq 'DateTime') {
+            # https://metacpan.org/pod/DateTime#$dt-%3Erfc3339
+            return $data->rfc3339;
+        }
+        return $data .q();
+    }
+}
+
 # from Perl hashref
 sub from_hash {
    my ($self, $hash) = @_;
@@ -144,10 +191,14 @@ sub _deserialize {
    my ($self, $type, $data) = @_;
    $log->debugf("deserializing %s with %s",Dumper($data), $type);

-    if ($type eq 'DateTime') {
+    if (grep( /^$type$/ , ('DATE_TIME', 'DATE'))) {
        return DateTime->from_epoch(epoch => str2time($data));
-    } elsif ( grep( /^$type$/, ('int', 'double', 'string', 'boolean'))) {
-        return $data;
+    } elsif ( grep( /^$type$/, ('int', 'double'))) {
+        return $data + 0;
+    } elsif ($type eq 'string') {
+        return $data . q();
+    } elsif ($type eq 'boolean') {
+        return !!$data;
    } else { # hash(model)
        my $_instance = eval "WWW::OpenAPIClient::Object::$type->new()";
        return $_instance->from_hash($data);
@@ -169,7 +220,7 @@ __PACKAGE__->method_documentation({
        read_only => '',
            },
    'date_time' => {
-        datatype => 'DateTime',
+        datatype => 'DATE_TIME',
        base_name => 'dateTime',
        description => '',
        format => '',
@@ -186,7 +237,7 @@ __PACKAGE__->method_documentation({

 __PACKAGE__->openapi_types( {
    'uuid' => 'string',
-    'date_time' => 'DateTime',
+    'date_time' => 'DATE_TIME',
    'map' => 'HASH[string,Animal]'
 } );

--- a/samples/client/petstore/perl/lib/WWW/OpenAPIClient/Object/Model200Response.pm
+++ b/samples/client/petstore/perl/lib/WWW/OpenAPIClient/Object/Model200Response.pm
@@ -100,13 +100,60 @@ sub TO_JSON {
    my $_data = {};
    foreach my $_key (keys %{$self->attribute_map}) {
        if (defined $self->{$_key}) {
-            $_data->{$self->attribute_map->{$_key}} = $self->{$_key};
+            my $_json_attribute = $self->attribute_map->{$_key};
+            my $_type = $self->openapi_types->{$_key};
+            my $_value = $self->{$_key};
+            if ($_type =~ /^array\[(.+)\]$/i) { # array
+                my $_subclass = $1;
+                $_data->{$_json_attribute} =  [ map { $self->_to_json_primitives($_subclass, $_) } @$_value ];
+            } elsif ($_type =~ /^hash\[string,(.+)\]$/i) { # hash
+                my $_subclass = $1;
+                my %_hash = ();
+                while (my($_key, $_element) = each %{$_value}) {
+                    $_hash{$_key} = $self->_to_json_primitives($_subclass, $_element);
+                }
+                $_data->{$_json_attribute} = \%_hash;
+            } elsif ( grep( /^$_type$/, ('int', 'double', 'string', 'boolean', 'DATE', 'DATE_TIME'))) {
+                $_data->{$_json_attribute} = $self->_to_json_primitives($_type, $_value);
+            } else {
+                $_data->{$_json_attribute} = $_value;
+            }
        }
    }

    return $_data;
 }

+# to_json non-array data
+sub _to_json_primitives {
+    my ($self, $type, $data) = @_;
+    if ( grep( /^$type$/, ('int', 'double'))) {
+        # https://metacpan.org/pod/JSON#simple-scalars
+        # numify it, ensuring it will be dumped as a number
+        return $data + 0;
+    } elsif ($type eq 'string') {
+        # https://metacpan.org/pod/JSON#simple-scalars
+        # stringified
+        return $data . q();
+    } elsif ($type eq 'boolean') {
+        # https://metacpan.org/pod/JSON#JSON::true,-JSON::false,-JSON::null
+        return $data ? \1 : \0;
+    } elsif ($type eq 'DATE') {
+        if (ref($data) eq 'DateTime') {
+            # https://metacpan.org/pod/DateTime#$dt-%3Eymd($optional_separator),-$dt-%3Emdy(...),-$dt-%3Edmy(...)
+            return $data->ymd;
+        }
+        return $data .q();
+    } elsif ($type eq 'DATE_TIME') {
+        # the date-time notation as defined by RFC 3339, section 5.6, for example, 2017-07-21T17:32:28Z
+        if (ref($data) eq 'DateTime') {
+            # https://metacpan.org/pod/DateTime#$dt-%3Erfc3339
+            return $data->rfc3339;
+        }
+        return $data .q();
+    }
+}
+
 # from Perl hashref
 sub from_hash {
    my ($self, $hash) = @_;
@@ -143,10 +190,14 @@ sub _deserialize {
    my ($self, $type, $data) = @_;
    $log->debugf("deserializing %s with %s",Dumper($data), $type);

-    if ($type eq 'DateTime') {
+    if (grep( /^$type$/ , ('DATE_TIME', 'DATE'))) {
        return DateTime->from_epoch(epoch => str2time($data));
-    } elsif ( grep( /^$type$/, ('int', 'double', 'string', 'boolean'))) {
-        return $data;
+    } elsif ( grep( /^$type$/, ('int', 'double'))) {
+        return $data + 0;
+    } elsif ($type eq 'string') {
+        return $data . q();
+    } elsif ($type eq 'boolean') {
+        return !!$data;
    } else { # hash(model)
        my $_instance = eval "WWW::OpenAPIClient::Object::$type->new()";
        return $_instance->from_hash($data);
--- a/samples/client/petstore/perl/lib/WWW/OpenAPIClient/Object/ModelReturn.pm
+++ b/samples/client/petstore/perl/lib/WWW/OpenAPIClient/Object/ModelReturn.pm
@@ -100,13 +100,60 @@ sub TO_JSON {
    my $_data = {};
    foreach my $_key (keys %{$self->attribute_map}) {
        if (defined $self->{$_key}) {
-            $_data->{$self->attribute_map->{$_key}} = $self->{$_key};
+            my $_json_attribute = $self->attribute_map->{$_key};
+            my $_type = $self->openapi_types->{$_key};
+            my $_value = $self->{$_key};
+            if ($_type =~ /^array\[(.+)\]$/i) { # array
+                my $_subclass = $1;
+                $_data->{$_json_attribute} =  [ map { $self->_to_json_primitives($_subclass, $_) } @$_value ];
+            } elsif ($_type =~ /^hash\[string,(.+)\]$/i) { # hash
+                my $_subclass = $1;
+                my %_hash = ();
+                while (my($_key, $_element) = each %{$_value}) {
+                    $_hash{$_key} = $self->_to_json_primitives($_subclass, $_element);
+                }
+                $_data->{$_json_attribute} = \%_hash;
+            } elsif ( grep( /^$_type$/, ('int', 'double', 'string', 'boolean', 'DATE', 'DATE_TIME'))) {
+                $_data->{$_json_attribute} = $self->_to_json_primitives($_type, $_value);
+            } else {
+                $_data->{$_json_attribute} = $_value;
+            }
        }
    }

    return $_data;
 }

+# to_json non-array data
+sub _to_json_primitives {
+    my ($self, $type, $data) = @_;
+    if ( grep( /^$type$/, ('int', 'double'))) {
+        # https://metacpan.org/pod/JSON#simple-scalars
+        # numify it, ensuring it will be dumped as a number
+        return $data + 0;
+    } elsif ($type eq 'string') {
+        # https://metacpan.org/pod/JSON#simple-scalars
+        # stringified
+        return $data . q();
+    } elsif ($type eq 'boolean') {
+        # https://metacpan.org/pod/JSON#JSON::true,-JSON::false,-JSON::null
+        return $data ? \1 : \0;
+    } elsif ($type eq 'DATE') {
+        if (ref($data) eq 'DateTime') {
+            # https://metacpan.org/pod/DateTime#$dt-%3Eymd($optional_separator),-$dt-%3Emdy(...),-$dt-%3Edmy(...)
+            return $data->ymd;
+        }
+        return $data .q();
+    } elsif ($type eq 'DATE_TIME') {
+        # the date-time notation as defined by RFC 3339, section 5.6, for example, 2017-07-21T17:32:28Z
+        if (ref($data) eq 'DateTime') {
+            # https://metacpan.org/pod/DateTime#$dt-%3Erfc3339
+            return $data->rfc3339;
+        }
+        return $data .q();
+    }
+}
+
 # from Perl hashref
 sub from_hash {
    my ($self, $hash) = @_;
@@ -143,10 +190,14 @@ sub _deserialize {
    my ($self, $type, $data) = @_;
    $log->debugf("deserializing %s with %s",Dumper($data), $type);

-    if ($type eq 'DateTime') {
+    if (grep( /^$type$/ , ('DATE_TIME', 'DATE'))) {
        return DateTime->from_epoch(epoch => str2time($data));
-    } elsif ( grep( /^$type$/, ('int', 'double', 'string', 'boolean'))) {
-        return $data;
+    } elsif ( grep( /^$type$/, ('int', 'double'))) {
+        return $data + 0;
+    } elsif ($type eq 'string') {
+        return $data . q();
+    } elsif ($type eq 'boolean') {
+        return !!$data;
    } else { # hash(model)
        my $_instance = eval "WWW::OpenAPIClient::Object::$type->new()";
        return $_instance->from_hash($data);
--- a/samples/client/petstore/perl/lib/WWW/OpenAPIClient/Object/Name.pm
+++ b/samples/client/petstore/perl/lib/WWW/OpenAPIClient/Object/Name.pm
@@ -100,13 +100,60 @@ sub TO_JSON {
    my $_data = {};
    foreach my $_key (keys %{$self->attribute_map}) {
        if (defined $self->{$_key}) {
-            $_data->{$self->attribute_map->{$_key}} = $self->{$_key};
+            my $_json_attribute = $self->attribute_map->{$_key};
+            my $_type = $self->openapi_types->{$_key};
+            my $_value = $self->{$_key};
+            if ($_type =~ /^array\[(.+)\]$/i) { # array
+                my $_subclass = $1;
+                $_data->{$_json_attribute} =  [ map { $self->_to_json_primitives($_subclass, $_) } @$_value ];
+            } elsif ($_type =~ /^hash\[string,(.+)\]$/i) { # hash
+                my $_subclass = $1;
+                my %_hash = ();
+                while (my($_key, $_element) = each %{$_value}) {
+                    $_hash{$_key} = $self->_to_json_primitives($_subclass, $_element);
+                }
+                $_data->{$_json_attribute} = \%_hash;
+            } elsif ( grep( /^$_type$/, ('int', 'double', 'string', 'boolean', 'DATE', 'DATE_TIME'))) {
+                $_data->{$_json_attribute} = $self->_to_json_primitives($_type, $_value);
+            } else {
+                $_data->{$_json_attribute} = $_value;
+            }
        }
    }

    return $_data;
 }

+# to_json non-array data
+sub _to_json_primitives {
+    my ($self, $type, $data) = @_;
+    if ( grep( /^$type$/, ('int', 'double'))) {
+        # https://metacpan.org/pod/JSON#simple-scalars
+        # numify it, ensuring it will be dumped as a number
+        return $data + 0;
+    } elsif ($type eq 'string') {
+        # https://metacpan.org/pod/JSON#simple-scalars
+        # stringified
+        return $data . q();
+    } elsif ($type eq 'boolean') {
+        # https://metacpan.org/pod/JSON#JSON::true,-JSON::false,-JSON::null
+        return $data ? \1 : \0;
+    } elsif ($type eq 'DATE') {
+        if (ref($data) eq 'DateTime') {
+            # https://metacpan.org/pod/DateTime#$dt-%3Eymd($optional_separator),-$dt-%3Emdy(...),-$dt-%3Edmy(...)
+            return $data->ymd;
+        }
+        return $data .q();
+    } elsif ($type eq 'DATE_TIME') {
+        # the date-time notation as defined by RFC 3339, section 5.6, for example, 2017-07-21T17:32:28Z
+        if (ref($data) eq 'DateTime') {
+            # https://metacpan.org/pod/DateTime#$dt-%3Erfc3339
+            return $data->rfc3339;
+        }
+        return $data .q();
+    }
+}
+
 # from Perl hashref
 sub from_hash {
    my ($self, $hash) = @_;
@@ -143,10 +190,14 @@ sub _deserialize {
    my ($self, $type, $data) = @_;
    $log->debugf("deserializing %s with %s",Dumper($data), $type);

-    if ($type eq 'DateTime') {
+    if (grep( /^$type$/ , ('DATE_TIME', 'DATE'))) {
        return DateTime->from_epoch(epoch => str2time($data));
-    } elsif ( grep( /^$type$/, ('int', 'double', 'string', 'boolean'))) {
-        return $data;
+    } elsif ( grep( /^$type$/, ('int', 'double'))) {
+        return $data + 0;
+    } elsif ($type eq 'string') {
+        return $data . q();
+    } elsif ($type eq 'boolean') {
+        return !!$data;
    } else { # hash(model)
        my $_instance = eval "WWW::OpenAPIClient::Object::$type->new()";
        return $_instance->from_hash($data);
--- a/samples/client/petstore/perl/lib/WWW/OpenAPIClient/Object/NullableClass.pm
+++ b/samples/client/petstore/perl/lib/WWW/OpenAPIClient/Object/NullableClass.pm
@@ -100,13 +100,60 @@ sub TO_JSON {
    my $_data = {};
    foreach my $_key (keys %{$self->attribute_map}) {
        if (defined $self->{$_key}) {
-            $_data->{$self->attribute_map->{$_key}} = $self->{$_key};
+            my $_json_attribute = $self->attribute_map->{$_key};
+            my $_type = $self->openapi_types->{$_key};
+            my $_value = $self->{$_key};
+            if ($_type =~ /^array\[(.+)\]$/i) { # array
+                my $_subclass = $1;
+                $_data->{$_json_attribute} =  [ map { $self->_to_json_primitives($_subclass, $_) } @$_value ];
+            } elsif ($_type =~ /^hash\[string,(.+)\]$/i) { # hash
+                my $_subclass = $1;
+                my %_hash = ();
+                while (my($_key, $_element) = each %{$_value}) {
+                    $_hash{$_key} = $self->_to_json_primitives($_subclass, $_element);
+                }
+                $_data->{$_json_attribute} = \%_hash;
+            } elsif ( grep( /^$_type$/, ('int', 'double', 'string', 'boolean', 'DATE', 'DATE_TIME'))) {
+                $_data->{$_json_attribute} = $self->_to_json_primitives($_type, $_value);
+            } else {
+                $_data->{$_json_attribute} = $_value;
+            }
        }
    }

    return $_data;
 }

+# to_json non-array data
+sub _to_json_primitives {
+    my ($self, $type, $data) = @_;
+    if ( grep( /^$type$/, ('int', 'double'))) {
+        # https://metacpan.org/pod/JSON#simple-scalars
+        # numify it, ensuring it will be dumped as a number
+        return $data + 0;
+    } elsif ($type eq 'string') {
+        # https://metacpan.org/pod/JSON#simple-scalars
+        # stringified
+        return $data . q();
+    } elsif ($type eq 'boolean') {
+        # https://metacpan.org/pod/JSON#JSON::true,-JSON::false,-JSON::null
+        return $data ? \1 : \0;
+    } elsif ($type eq 'DATE') {
+        if (ref($data) eq 'DateTime') {
+            # https://metacpan.org/pod/DateTime#$dt-%3Eymd($optional_separator),-$dt-%3Emdy(...),-$dt-%3Edmy(...)
+            return $data->ymd;
+        }
+        return $data .q();
+    } elsif ($type eq 'DATE_TIME') {
+        # the date-time notation as defined by RFC 3339, section 5.6, for example, 2017-07-21T17:32:28Z
+        if (ref($data) eq 'DateTime') {
+            # https://metacpan.org/pod/DateTime#$dt-%3Erfc3339
+            return $data->rfc3339;
+        }
+        return $data .q();
+    }
+}
+
 # from Perl hashref
 sub from_hash {
    my ($self, $hash) = @_;
@@ -143,10 +190,14 @@ sub _deserialize {
    my ($self, $type, $data) = @_;
    $log->debugf("deserializing %s with %s",Dumper($data), $type);

-    if ($type eq 'DateTime') {
+    if (grep( /^$type$/ , ('DATE_TIME', 'DATE'))) {
        return DateTime->from_epoch(epoch => str2time($data));
-    } elsif ( grep( /^$type$/, ('int', 'double', 'string', 'boolean'))) {
-        return $data;
+    } elsif ( grep( /^$type$/, ('int', 'double'))) {
+        return $data + 0;
+    } elsif ($type eq 'string') {
+        return $data . q();
+    } elsif ($type eq 'boolean') {
+        return !!$data;
    } else { # hash(model)
        my $_instance = eval "WWW::OpenAPIClient::Object::$type->new()";
        return $_instance->from_hash($data);
@@ -189,14 +240,14 @@ __PACKAGE__->method_documentation({
        read_only => '',
            },
    'date_prop' => {
-        datatype => 'DateTime',
+        datatype => 'DATE',
        base_name => 'date_prop',
        description => '',
        format => '',
        read_only => '',
            },
    'datetime_prop' => {
-        datatype => 'DateTime',
+        datatype => 'DATE_TIME',
        base_name => 'datetime_prop',
        description => '',
        format => '',
@@ -251,8 +302,8 @@ __PACKAGE__->openapi_types( {
    'number_prop' => 'double',
    'boolean_prop' => 'boolean',
    'string_prop' => 'string',
-    'date_prop' => 'DateTime',
-    'datetime_prop' => 'DateTime',
+    'date_prop' => 'DATE',
+    'datetime_prop' => 'DATE_TIME',
    'array_nullable_prop' => 'ARRAY[object]',
    'array_and_items_nullable_prop' => 'ARRAY[object]',
    'array_items_nullable' => 'ARRAY[object]',
--- a/samples/client/petstore/perl/lib/WWW/OpenAPIClient/Object/NumberOnly.pm
+++ b/samples/client/petstore/perl/lib/WWW/OpenAPIClient/Object/NumberOnly.pm
@@ -100,13 +100,60 @@ sub TO_JSON {
    my $_data = {};
    foreach my $_key (keys %{$self->attribute_map}) {
        if (defined $self->{$_key}) {
-            $_data->{$self->attribute_map->{$_key}} = $self->{$_key};
+            my $_json_attribute = $self->attribute_map->{$_key};
+            my $_type = $self->openapi_types->{$_key};
+            my $_value = $self->{$_key};
+            if ($_type =~ /^array\[(.+)\]$/i) { # array
+                my $_subclass = $1;
+                $_data->{$_json_attribute} =  [ map { $self->_to_json_primitives($_subclass, $_) } @$_value ];
+            } elsif ($_type =~ /^hash\[string,(.+)\]$/i) { # hash
+                my $_subclass = $1;
+                my %_hash = ();
+                while (my($_key, $_element) = each %{$_value}) {
+                    $_hash{$_key} = $self->_to_json_primitives($_subclass, $_element);
+                }
+                $_data->{$_json_attribute} = \%_hash;
+            } elsif ( grep( /^$_type$/, ('int', 'double', 'string', 'boolean', 'DATE', 'DATE_TIME'))) {
+                $_data->{$_json_attribute} = $self->_to_json_primitives($_type, $_value);
+            } else {
+                $_data->{$_json_attribute} = $_value;
+            }
        }
    }

    return $_data;
 }

+# to_json non-array data
+sub _to_json_primitives {
+    my ($self, $type, $data) = @_;
+    if ( grep( /^$type$/, ('int', 'double'))) {
+        # https://metacpan.org/pod/JSON#simple-scalars
+        # numify it, ensuring it will be dumped as a number
+        return $data + 0;
+    } elsif ($type eq 'string') {
+        # https://metacpan.org/pod/JSON#simple-scalars
+        # stringified
+        return $data . q();
+    } elsif ($type eq 'boolean') {
+        # https://metacpan.org/pod/JSON#JSON::true,-JSON::false,-JSON::null
+        return $data ? \1 : \0;
+    } elsif ($type eq 'DATE') {
+        if (ref($data) eq 'DateTime') {
+            # https://metacpan.org/pod/DateTime#$dt-%3Eymd($optional_separator),-$dt-%3Emdy(...),-$dt-%3Edmy(...)
+            return $data->ymd;
+        }
+        return $data .q();
+    } elsif ($type eq 'DATE_TIME') {
+        # the date-time notation as defined by RFC 3339, section 5.6, for example, 2017-07-21T17:32:28Z
+        if (ref($data) eq 'DateTime') {
+            # https://metacpan.org/pod/DateTime#$dt-%3Erfc3339
+            return $data->rfc3339;
+        }
+        return $data .q();
+    }
+}
+
 # from Perl hashref
 sub from_hash {
    my ($self, $hash) = @_;
@@ -143,10 +190,14 @@ sub _deserialize {
    my ($self, $type, $data) = @_;
    $log->debugf("deserializing %s with %s",Dumper($data), $type);

-    if ($type eq 'DateTime') {
+    if (grep( /^$type$/ , ('DATE_TIME', 'DATE'))) {
        return DateTime->from_epoch(epoch => str2time($data));
-    } elsif ( grep( /^$type$/, ('int', 'double', 'string', 'boolean'))) {
-        return $data;
+    } elsif ( grep( /^$type$/, ('int', 'double'))) {
+        return $data + 0;
+    } elsif ($type eq 'string') {
+        return $data . q();
+    } elsif ($type eq 'boolean') {
+        return !!$data;
    } else { # hash(model)
        my $_instance = eval "WWW::OpenAPIClient::Object::$type->new()";
        return $_instance->from_hash($data);
--- a/samples/client/petstore/perl/lib/WWW/OpenAPIClient/Object/ObjectWithDeprecatedFields.pm
+++ b/samples/client/petstore/perl/lib/WWW/OpenAPIClient/Object/ObjectWithDeprecatedFields.pm
@@ -101,13 +101,60 @@ sub TO_JSON {
    my $_data = {};
    foreach my $_key (keys %{$self->attribute_map}) {
        if (defined $self->{$_key}) {
-            $_data->{$self->attribute_map->{$_key}} = $self->{$_key};
+            my $_json_attribute = $self->attribute_map->{$_key};
+            my $_type = $self->openapi_types->{$_key};
+            my $_value = $self->{$_key};
+            if ($_type =~ /^array\[(.+)\]$/i) { # array
+                my $_subclass = $1;
+                $_data->{$_json_attribute} =  [ map { $self->_to_json_primitives($_subclass, $_) } @$_value ];
+            } elsif ($_type =~ /^hash\[string,(.+)\]$/i) { # hash
+                my $_subclass = $1;
+                my %_hash = ();
+                while (my($_key, $_element) = each %{$_value}) {
+                    $_hash{$_key} = $self->_to_json_primitives($_subclass, $_element);
+                }
+                $_data->{$_json_attribute} = \%_hash;
+            } elsif ( grep( /^$_type$/, ('int', 'double', 'string', 'boolean', 'DATE', 'DATE_TIME'))) {
+                $_data->{$_json_attribute} = $self->_to_json_primitives($_type, $_value);
+            } else {
+                $_data->{$_json_attribute} = $_value;
+            }
        }
    }

    return $_data;
 }

+# to_json non-array data
+sub _to_json_primitives {
+    my ($self, $type, $data) = @_;
+    if ( grep( /^$type$/, ('int', 'double'))) {
+        # https://metacpan.org/pod/JSON#simple-scalars
+        # numify it, ensuring it will be dumped as a number
+        return $data + 0;
+    } elsif ($type eq 'string') {
+        # https://metacpan.org/pod/JSON#simple-scalars
+        # stringified
+        return $data . q();
+    } elsif ($type eq 'boolean') {
+        # https://metacpan.org/pod/JSON#JSON::true,-JSON::false,-JSON::null
+        return $data ? \1 : \0;
+    } elsif ($type eq 'DATE') {
+        if (ref($data) eq 'DateTime') {
+            # https://metacpan.org/pod/DateTime#$dt-%3Eymd($optional_separator),-$dt-%3Emdy(...),-$dt-%3Edmy(...)
+            return $data->ymd;
+        }
+        return $data .q();
+    } elsif ($type eq 'DATE_TIME') {
+        # the date-time notation as defined by RFC 3339, section 5.6, for example, 2017-07-21T17:32:28Z
+        if (ref($data) eq 'DateTime') {
+            # https://metacpan.org/pod/DateTime#$dt-%3Erfc3339
+            return $data->rfc3339;
+        }
+        return $data .q();
+    }
+}
+
 # from Perl hashref
 sub from_hash {
    my ($self, $hash) = @_;
@@ -144,10 +191,14 @@ sub _deserialize {
    my ($self, $type, $data) = @_;
    $log->debugf("deserializing %s with %s",Dumper($data), $type);

-    if ($type eq 'DateTime') {
+    if (grep( /^$type$/ , ('DATE_TIME', 'DATE'))) {
        return DateTime->from_epoch(epoch => str2time($data));
-    } elsif ( grep( /^$type$/, ('int', 'double', 'string', 'boolean'))) {
-        return $data;
+    } elsif ( grep( /^$type$/, ('int', 'double'))) {
+        return $data + 0;
+    } elsif ($type eq 'string') {
+        return $data . q();
+    } elsif ($type eq 'boolean') {
+        return !!$data;
    } else { # hash(model)
        my $_instance = eval "WWW::OpenAPIClient::Object::$type->new()";
        return $_instance->from_hash($data);
--- a/samples/client/petstore/perl/lib/WWW/OpenAPIClient/Object/Order.pm
+++ b/samples/client/petstore/perl/lib/WWW/OpenAPIClient/Object/Order.pm
@@ -100,13 +100,60 @@ sub TO_JSON {
    my $_data = {};
    foreach my $_key (keys %{$self->attribute_map}) {
        if (defined $self->{$_key}) {
-            $_data->{$self->attribute_map->{$_key}} = $self->{$_key};
+            my $_json_attribute = $self->attribute_map->{$_key};
+            my $_type = $self->openapi_types->{$_key};
+            my $_value = $self->{$_key};
+            if ($_type =~ /^array\[(.+)\]$/i) { # array
+                my $_subclass = $1;
+                $_data->{$_json_attribute} =  [ map { $self->_to_json_primitives($_subclass, $_) } @$_value ];
+            } elsif ($_type =~ /^hash\[string,(.+)\]$/i) { # hash
+                my $_subclass = $1;
+                my %_hash = ();
+                while (my($_key, $_element) = each %{$_value}) {
+                    $_hash{$_key} = $self->_to_json_primitives($_subclass, $_element);
+                }
+                $_data->{$_json_attribute} = \%_hash;
+            } elsif ( grep( /^$_type$/, ('int', 'double', 'string', 'boolean', 'DATE', 'DATE_TIME'))) {
+                $_data->{$_json_attribute} = $self->_to_json_primitives($_type, $_value);
+            } else {
+                $_data->{$_json_attribute} = $_value;
+            }
        }
    }

    return $_data;
 }

+# to_json non-array data
+sub _to_json_primitives {
+    my ($self, $type, $data) = @_;
+    if ( grep( /^$type$/, ('int', 'double'))) {
+        # https://metacpan.org/pod/JSON#simple-scalars
+        # numify it, ensuring it will be dumped as a number
+        return $data + 0;
+    } elsif ($type eq 'string') {
+        # https://metacpan.org/pod/JSON#simple-scalars
+        # stringified
+        return $data . q();
+    } elsif ($type eq 'boolean') {
+        # https://metacpan.org/pod/JSON#JSON::true,-JSON::false,-JSON::null
+        return $data ? \1 : \0;
+    } elsif ($type eq 'DATE') {
+        if (ref($data) eq 'DateTime') {
+            # https://metacpan.org/pod/DateTime#$dt-%3Eymd($optional_separator),-$dt-%3Emdy(...),-$dt-%3Edmy(...)
+            return $data->ymd;
+        }
+        return $data .q();
+    } elsif ($type eq 'DATE_TIME') {
+        # the date-time notation as defined by RFC 3339, section 5.6, for example, 2017-07-21T17:32:28Z
+        if (ref($data) eq 'DateTime') {
+            # https://metacpan.org/pod/DateTime#$dt-%3Erfc3339
+            return $data->rfc3339;
+        }
+        return $data .q();
+    }
+}
+
 # from Perl hashref
 sub from_hash {
    my ($self, $hash) = @_;
@@ -143,10 +190,14 @@ sub _deserialize {
    my ($self, $type, $data) = @_;
    $log->debugf("deserializing %s with %s",Dumper($data), $type);

-    if ($type eq 'DateTime') {
+    if (grep( /^$type$/ , ('DATE_TIME', 'DATE'))) {
        return DateTime->from_epoch(epoch => str2time($data));
-    } elsif ( grep( /^$type$/, ('int', 'double', 'string', 'boolean'))) {
-        return $data;
+    } elsif ( grep( /^$type$/, ('int', 'double'))) {
+        return $data + 0;
+    } elsif ($type eq 'string') {
+        return $data . q();
+    } elsif ($type eq 'boolean') {
+        return !!$data;
    } else { # hash(model)
        my $_instance = eval "WWW::OpenAPIClient::Object::$type->new()";
        return $_instance->from_hash($data);
@@ -182,7 +233,7 @@ __PACKAGE__->method_documentation({
        read_only => '',
            },
    'ship_date' => {
-        datatype => 'DateTime',
+        datatype => 'DATE_TIME',
        base_name => 'shipDate',
        description => '',
        format => '',
@@ -208,7 +259,7 @@ __PACKAGE__->openapi_types( {
    'id' => 'int',
    'pet_id' => 'int',
    'quantity' => 'int',
-    'ship_date' => 'DateTime',
+    'ship_date' => 'DATE_TIME',
    'status' => 'string',
    'complete' => 'boolean'
 } );
--- a/samples/client/petstore/perl/lib/WWW/OpenAPIClient/Object/OuterComposite.pm
+++ b/samples/client/petstore/perl/lib/WWW/OpenAPIClient/Object/OuterComposite.pm
@@ -100,13 +100,60 @@ sub TO_JSON {
    my $_data = {};
    foreach my $_key (keys %{$self->attribute_map}) {
        if (defined $self->{$_key}) {
-            $_data->{$self->attribute_map->{$_key}} = $self->{$_key};
+            my $_json_attribute = $self->attribute_map->{$_key};
+            my $_type = $self->openapi_types->{$_key};
+            my $_value = $self->{$_key};
+            if ($_type =~ /^array\[(.+)\]$/i) { # array
+                my $_subclass = $1;
+                $_data->{$_json_attribute} =  [ map { $self->_to_json_primitives($_subclass, $_) } @$_value ];
+            } elsif ($_type =~ /^hash\[string,(.+)\]$/i) { # hash
+                my $_subclass = $1;
+                my %_hash = ();
+                while (my($_key, $_element) = each %{$_value}) {
+                    $_hash{$_key} = $self->_to_json_primitives($_subclass, $_element);
+                }
+                $_data->{$_json_attribute} = \%_hash;
+            } elsif ( grep( /^$_type$/, ('int', 'double', 'string', 'boolean', 'DATE', 'DATE_TIME'))) {
+                $_data->{$_json_attribute} = $self->_to_json_primitives($_type, $_value);
+            } else {
+                $_data->{$_json_attribute} = $_value;
+            }
        }
    }

    return $_data;
 }

+# to_json non-array data
+sub _to_json_primitives {
+    my ($self, $type, $data) = @_;
+    if ( grep( /^$type$/, ('int', 'double'))) {
+        # https://metacpan.org/pod/JSON#simple-scalars
+        # numify it, ensuring it will be dumped as a number
+        return $data + 0;
+    } elsif ($type eq 'string') {
+        # https://metacpan.org/pod/JSON#simple-scalars
+        # stringified
+        return $data . q();
+    } elsif ($type eq 'boolean') {
+        # https://metacpan.org/pod/JSON#JSON::true,-JSON::false,-JSON::null
+        return $data ? \1 : \0;
+    } elsif ($type eq 'DATE') {
+        if (ref($data) eq 'DateTime') {
+            # https://metacpan.org/pod/DateTime#$dt-%3Eymd($optional_separator),-$dt-%3Emdy(...),-$dt-%3Edmy(...)
+            return $data->ymd;
+        }
+        return $data .q();
+    } elsif ($type eq 'DATE_TIME') {
+        # the date-time notation as defined by RFC 3339, section 5.6, for example, 2017-07-21T17:32:28Z
+        if (ref($data) eq 'DateTime') {
+            # https://metacpan.org/pod/DateTime#$dt-%3Erfc3339
+            return $data->rfc3339;
+        }
+        return $data .q();
+    }
+}
+
 # from Perl hashref
 sub from_hash {
    my ($self, $hash) = @_;
@@ -143,10 +190,14 @@ sub _deserialize {
    my ($self, $type, $data) = @_;
    $log->debugf("deserializing %s with %s",Dumper($data), $type);

-    if ($type eq 'DateTime') {
+    if (grep( /^$type$/ , ('DATE_TIME', 'DATE'))) {
        return DateTime->from_epoch(epoch => str2time($data));
-    } elsif ( grep( /^$type$/, ('int', 'double', 'string', 'boolean'))) {
-        return $data;
+    } elsif ( grep( /^$type$/, ('int', 'double'))) {
+        return $data + 0;
+    } elsif ($type eq 'string') {
+        return $data . q();
+    } elsif ($type eq 'boolean') {
+        return !!$data;
    } else { # hash(model)
        my $_instance = eval "WWW::OpenAPIClient::Object::$type->new()";
        return $_instance->from_hash($data);
--- a/samples/client/petstore/perl/lib/WWW/OpenAPIClient/Object/OuterEnum.pm
+++ b/samples/client/petstore/perl/lib/WWW/OpenAPIClient/Object/OuterEnum.pm
@@ -100,13 +100,60 @@ sub TO_JSON {
    my $_data = {};
    foreach my $_key (keys %{$self->attribute_map}) {
        if (defined $self->{$_key}) {
-            $_data->{$self->attribute_map->{$_key}} = $self->{$_key};
+            my $_json_attribute = $self->attribute_map->{$_key};
+            my $_type = $self->openapi_types->{$_key};
+            my $_value = $self->{$_key};
+            if ($_type =~ /^array\[(.+)\]$/i) { # array
+                my $_subclass = $1;
+                $_data->{$_json_attribute} =  [ map { $self->_to_json_primitives($_subclass, $_) } @$_value ];
+            } elsif ($_type =~ /^hash\[string,(.+)\]$/i) { # hash
+                my $_subclass = $1;
+                my %_hash = ();
+                while (my($_key, $_element) = each %{$_value}) {
+                    $_hash{$_key} = $self->_to_json_primitives($_subclass, $_element);
+                }
+                $_data->{$_json_attribute} = \%_hash;
+            } elsif ( grep( /^$_type$/, ('int', 'double', 'string', 'boolean', 'DATE', 'DATE_TIME'))) {
+                $_data->{$_json_attribute} = $self->_to_json_primitives($_type, $_value);
+            } else {
+                $_data->{$_json_attribute} = $_value;
+            }
        }
    }

    return $_data;
 }

+# to_json non-array data
+sub _to_json_primitives {
+    my ($self, $type, $data) = @_;
+    if ( grep( /^$type$/, ('int', 'double'))) {
+        # https://metacpan.org/pod/JSON#simple-scalars
+        # numify it, ensuring it will be dumped as a number
+        return $data + 0;
+    } elsif ($type eq 'string') {
+        # https://metacpan.org/pod/JSON#simple-scalars
+        # stringified
+        return $data . q();
+    } elsif ($type eq 'boolean') {
+        # https://metacpan.org/pod/JSON#JSON::true,-JSON::false,-JSON::null
+        return $data ? \1 : \0;
+    } elsif ($type eq 'DATE') {
+        if (ref($data) eq 'DateTime') {
+            # https://metacpan.org/pod/DateTime#$dt-%3Eymd($optional_separator),-$dt-%3Emdy(...),-$dt-%3Edmy(...)
+            return $data->ymd;
+        }
+        return $data .q();
+    } elsif ($type eq 'DATE_TIME') {
+        # the date-time notation as defined by RFC 3339, section 5.6, for example, 2017-07-21T17:32:28Z
+        if (ref($data) eq 'DateTime') {
+            # https://metacpan.org/pod/DateTime#$dt-%3Erfc3339
+            return $data->rfc3339;
+        }
+        return $data .q();
+    }
+}
+
 # from Perl hashref
 sub from_hash {
    my ($self, $hash) = @_;
@@ -143,10 +190,14 @@ sub _deserialize {
    my ($self, $type, $data) = @_;
    $log->debugf("deserializing %s with %s",Dumper($data), $type);

-    if ($type eq 'DateTime') {
+    if (grep( /^$type$/ , ('DATE_TIME', 'DATE'))) {
        return DateTime->from_epoch(epoch => str2time($data));
-    } elsif ( grep( /^$type$/, ('int', 'double', 'string', 'boolean'))) {
-        return $data;
+    } elsif ( grep( /^$type$/, ('int', 'double'))) {
+        return $data + 0;
+    } elsif ($type eq 'string') {
+        return $data . q();
+    } elsif ($type eq 'boolean') {
+        return !!$data;
    } else { # hash(model)
        my $_instance = eval "WWW::OpenAPIClient::Object::$type->new()";
        return $_instance->from_hash($data);
--- a/samples/client/petstore/perl/lib/WWW/OpenAPIClient/Object/OuterEnumDefaultValue.pm
+++ b/samples/client/petstore/perl/lib/WWW/OpenAPIClient/Object/OuterEnumDefaultValue.pm
@@ -100,13 +100,60 @@ sub TO_JSON {
    my $_data = {};
    foreach my $_key (keys %{$self->attribute_map}) {
        if (defined $self->{$_key}) {
-            $_data->{$self->attribute_map->{$_key}} = $self->{$_key};
+            my $_json_attribute = $self->attribute_map->{$_key};
+            my $_type = $self->openapi_types->{$_key};
+            my $_value = $self->{$_key};
+            if ($_type =~ /^array\[(.+)\]$/i) { # array
+                my $_subclass = $1;
+                $_data->{$_json_attribute} =  [ map { $self->_to_json_primitives($_subclass, $_) } @$_value ];
+            } elsif ($_type =~ /^hash\[string,(.+)\]$/i) { # hash
+                my $_subclass = $1;
+                my %_hash = ();
+                while (my($_key, $_element) = each %{$_value}) {
+                    $_hash{$_key} = $self->_to_json_primitives($_subclass, $_element);
+                }
+                $_data->{$_json_attribute} = \%_hash;
+            } elsif ( grep( /^$_type$/, ('int', 'double', 'string', 'boolean', 'DATE', 'DATE_TIME'))) {
+                $_data->{$_json_attribute} = $self->_to_json_primitives($_type, $_value);
+            } else {
+                $_data->{$_json_attribute} = $_value;
+            }
        }
    }

    return $_data;
 }

+# to_json non-array data
+sub _to_json_primitives {
+    my ($self, $type, $data) = @_;
+    if ( grep( /^$type$/, ('int', 'double'))) {
+        # https://metacpan.org/pod/JSON#simple-scalars
+        # numify it, ensuring it will be dumped as a number
+        return $data + 0;
+    } elsif ($type eq 'string') {
+        # https://metacpan.org/pod/JSON#simple-scalars
+        # stringified
+        return $data . q();
+    } elsif ($type eq 'boolean') {
+        # https://metacpan.org/pod/JSON#JSON::true,-JSON::false,-JSON::null
+        return $data ? \1 : \0;
+    } elsif ($type eq 'DATE') {
+        if (ref($data) eq 'DateTime') {
+            # https://metacpan.org/pod/DateTime#$dt-%3Eymd($optional_separator),-$dt-%3Emdy(...),-$dt-%3Edmy(...)
+            return $data->ymd;
+        }
+        return $data .q();
+    } elsif ($type eq 'DATE_TIME') {
+        # the date-time notation as defined by RFC 3339, section 5.6, for example, 2017-07-21T17:32:28Z
+        if (ref($data) eq 'DateTime') {
+            # https://metacpan.org/pod/DateTime#$dt-%3Erfc3339
+            return $data->rfc3339;
+        }
+        return $data .q();
+    }
+}
+
 # from Perl hashref
 sub from_hash {
    my ($self, $hash) = @_;
@@ -143,10 +190,14 @@ sub _deserialize {
    my ($self, $type, $data) = @_;
    $log->debugf("deserializing %s with %s",Dumper($data), $type);

-    if ($type eq 'DateTime') {
+    if (grep( /^$type$/ , ('DATE_TIME', 'DATE'))) {
        return DateTime->from_epoch(epoch => str2time($data));
-    } elsif ( grep( /^$type$/, ('int', 'double', 'string', 'boolean'))) {
-        return $data;
+    } elsif ( grep( /^$type$/, ('int', 'double'))) {
+        return $data + 0;
+    } elsif ($type eq 'string') {
+        return $data . q();
+    } elsif ($type eq 'boolean') {
+        return !!$data;
    } else { # hash(model)
        my $_instance = eval "WWW::OpenAPIClient::Object::$type->new()";
        return $_instance->from_hash($data);
--- a/samples/client/petstore/perl/lib/WWW/OpenAPIClient/Object/OuterEnumInteger.pm
+++ b/samples/client/petstore/perl/lib/WWW/OpenAPIClient/Object/OuterEnumInteger.pm
@@ -100,13 +100,60 @@ sub TO_JSON {
    my $_data = {};
    foreach my $_key (keys %{$self->attribute_map}) {
        if (defined $self->{$_key}) {
-            $_data->{$self->attribute_map->{$_key}} = $self->{$_key};
+            my $_json_attribute = $self->attribute_map->{$_key};
+            my $_type = $self->openapi_types->{$_key};
+            my $_value = $self->{$_key};
+            if ($_type =~ /^array\[(.+)\]$/i) { # array
+                my $_subclass = $1;
+                $_data->{$_json_attribute} =  [ map { $self->_to_json_primitives($_subclass, $_) } @$_value ];
+            } elsif ($_type =~ /^hash\[string,(.+)\]$/i) { # hash
+                my $_subclass = $1;
+                my %_hash = ();
+                while (my($_key, $_element) = each %{$_value}) {
+                    $_hash{$_key} = $self->_to_json_primitives($_subclass, $_element);
+                }
+                $_data->{$_json_attribute} = \%_hash;
+            } elsif ( grep( /^$_type$/, ('int', 'double', 'string', 'boolean', 'DATE', 'DATE_TIME'))) {
+                $_data->{$_json_attribute} = $self->_to_json_primitives($_type, $_value);
+            } else {
+                $_data->{$_json_attribute} = $_value;
+            }
        }
    }

    return $_data;
 }

+# to_json non-array data
+sub _to_json_primitives {
+    my ($self, $type, $data) = @_;
+    if ( grep( /^$type$/, ('int', 'double'))) {
+        # https://metacpan.org/pod/JSON#simple-scalars
+        # numify it, ensuring it will be dumped as a number
+        return $data + 0;
+    } elsif ($type eq 'string') {
+        # https://metacpan.org/pod/JSON#simple-scalars
+        # stringified
+        return $data . q();
+    } elsif ($type eq 'boolean') {
+        # https://metacpan.org/pod/JSON#JSON::true,-JSON::false,-JSON::null
+        return $data ? \1 : \0;
+    } elsif ($type eq 'DATE') {
+        if (ref($data) eq 'DateTime') {
+            # https://metacpan.org/pod/DateTime#$dt-%3Eymd($optional_separator),-$dt-%3Emdy(...),-$dt-%3Edmy(...)
+            return $data->ymd;
+        }
+        return $data .q();
+    } elsif ($type eq 'DATE_TIME') {
+        # the date-time notation as defined by RFC 3339, section 5.6, for example, 2017-07-21T17:32:28Z
+        if (ref($data) eq 'DateTime') {
+            # https://metacpan.org/pod/DateTime#$dt-%3Erfc3339
+            return $data->rfc3339;
+        }
+        return $data .q();
+    }
+}
+
 # from Perl hashref
 sub from_hash {
    my ($self, $hash) = @_;
@@ -143,10 +190,14 @@ sub _deserialize {
    my ($self, $type, $data) = @_;
    $log->debugf("deserializing %s with %s",Dumper($data), $type);

-    if ($type eq 'DateTime') {
+    if (grep( /^$type$/ , ('DATE_TIME', 'DATE'))) {
        return DateTime->from_epoch(epoch => str2time($data));
-    } elsif ( grep( /^$type$/, ('int', 'double', 'string', 'boolean'))) {
-        return $data;
+    } elsif ( grep( /^$type$/, ('int', 'double'))) {
+        return $data + 0;
+    } elsif ($type eq 'string') {
+        return $data . q();
+    } elsif ($type eq 'boolean') {
+        return !!$data;
    } else { # hash(model)
        my $_instance = eval "WWW::OpenAPIClient::Object::$type->new()";
        return $_instance->from_hash($data);
--- a/samples/client/petstore/perl/lib/WWW/OpenAPIClient/Object/OuterEnumIntegerDefaultValue.pm
+++ b/samples/client/petstore/perl/lib/WWW/OpenAPIClient/Object/OuterEnumIntegerDefaultValue.pm
@@ -100,13 +100,60 @@ sub TO_JSON {
    my $_data = {};
    foreach my $_key (keys %{$self->attribute_map}) {
        if (defined $self->{$_key}) {
-            $_data->{$self->attribute_map->{$_key}} = $self->{$_key};
+            my $_json_attribute = $self->attribute_map->{$_key};
+            my $_type = $self->openapi_types->{$_key};
+            my $_value = $self->{$_key};
+            if ($_type =~ /^array\[(.+)\]$/i) { # array
+                my $_subclass = $1;
+                $_data->{$_json_attribute} =  [ map { $self->_to_json_primitives($_subclass, $_) } @$_value ];
+            } elsif ($_type =~ /^hash\[string,(.+)\]$/i) { # hash
+                my $_subclass = $1;
+                my %_hash = ();
+                while (my($_key, $_element) = each %{$_value}) {
+                    $_hash{$_key} = $self->_to_json_primitives($_subclass, $_element);
+                }
+                $_data->{$_json_attribute} = \%_hash;
+            } elsif ( grep( /^$_type$/, ('int', 'double', 'string', 'boolean', 'DATE', 'DATE_TIME'))) {
+                $_data->{$_json_attribute} = $self->_to_json_primitives($_type, $_value);
+            } else {
+                $_data->{$_json_attribute} = $_value;
+            }
        }
    }

    return $_data;
 }

+# to_json non-array data
+sub _to_json_primitives {
+    my ($self, $type, $data) = @_;
+    if ( grep( /^$type$/, ('int', 'double'))) {
+        # https://metacpan.org/pod/JSON#simple-scalars
+        # numify it, ensuring it will be dumped as a number
+        return $data + 0;
+    } elsif ($type eq 'string') {
+        # https://metacpan.org/pod/JSON#simple-scalars
+        # stringified
+        return $data . q();
+    } elsif ($type eq 'boolean') {
+        # https://metacpan.org/pod/JSON#JSON::true,-JSON::false,-JSON::null
+        return $data ? \1 : \0;
+    } elsif ($type eq 'DATE') {
+        if (ref($data) eq 'DateTime') {
+            # https://metacpan.org/pod/DateTime#$dt-%3Eymd($optional_separator),-$dt-%3Emdy(...),-$dt-%3Edmy(...)
+            return $data->ymd;
+        }
+        return $data .q();
+    } elsif ($type eq 'DATE_TIME') {
+        # the date-time notation as defined by RFC 3339, section 5.6, for example, 2017-07-21T17:32:28Z
+        if (ref($data) eq 'DateTime') {
+            # https://metacpan.org/pod/DateTime#$dt-%3Erfc3339
+            return $data->rfc3339;
+        }
+        return $data .q();
+    }
+}
+
 # from Perl hashref
 sub from_hash {
    my ($self, $hash) = @_;
@@ -143,10 +190,14 @@ sub _deserialize {
    my ($self, $type, $data) = @_;
    $log->debugf("deserializing %s with %s",Dumper($data), $type);

-    if ($type eq 'DateTime') {
+    if (grep( /^$type$/ , ('DATE_TIME', 'DATE'))) {
        return DateTime->from_epoch(epoch => str2time($data));
-    } elsif ( grep( /^$type$/, ('int', 'double', 'string', 'boolean'))) {
-        return $data;
+    } elsif ( grep( /^$type$/, ('int', 'double'))) {
+        return $data + 0;
+    } elsif ($type eq 'string') {
+        return $data . q();
+    } elsif ($type eq 'boolean') {
+        return !!$data;
    } else { # hash(model)
        my $_instance = eval "WWW::OpenAPIClient::Object::$type->new()";
        return $_instance->from_hash($data);
--- a/samples/client/petstore/perl/lib/WWW/OpenAPIClient/Object/OuterObjectWithEnumProperty.pm
+++ b/samples/client/petstore/perl/lib/WWW/OpenAPIClient/Object/OuterObjectWithEnumProperty.pm
@@ -101,13 +101,60 @@ sub TO_JSON {
    my $_data = {};
    foreach my $_key (keys %{$self->attribute_map}) {
        if (defined $self->{$_key}) {
-            $_data->{$self->attribute_map->{$_key}} = $self->{$_key};
+            my $_json_attribute = $self->attribute_map->{$_key};
+            my $_type = $self->openapi_types->{$_key};
+            my $_value = $self->{$_key};
+            if ($_type =~ /^array\[(.+)\]$/i) { # array
+                my $_subclass = $1;
+                $_data->{$_json_attribute} =  [ map { $self->_to_json_primitives($_subclass, $_) } @$_value ];
+            } elsif ($_type =~ /^hash\[string,(.+)\]$/i) { # hash
+                my $_subclass = $1;
+                my %_hash = ();
+                while (my($_key, $_element) = each %{$_value}) {
+                    $_hash{$_key} = $self->_to_json_primitives($_subclass, $_element);
+                }
+                $_data->{$_json_attribute} = \%_hash;
+            } elsif ( grep( /^$_type$/, ('int', 'double', 'string', 'boolean', 'DATE', 'DATE_TIME'))) {
+                $_data->{$_json_attribute} = $self->_to_json_primitives($_type, $_value);
+            } else {
+                $_data->{$_json_attribute} = $_value;
+            }
        }
    }

    return $_data;
 }

+# to_json non-array data
+sub _to_json_primitives {
+    my ($self, $type, $data) = @_;
+    if ( grep( /^$type$/, ('int', 'double'))) {
+        # https://metacpan.org/pod/JSON#simple-scalars
+        # numify it, ensuring it will be dumped as a number
+        return $data + 0;
+    } elsif ($type eq 'string') {
+        # https://metacpan.org/pod/JSON#simple-scalars
+        # stringified
+        return $data . q();
+    } elsif ($type eq 'boolean') {
+        # https://metacpan.org/pod/JSON#JSON::true,-JSON::false,-JSON::null
+        return $data ? \1 : \0;
+    } elsif ($type eq 'DATE') {
+        if (ref($data) eq 'DateTime') {
+            # https://metacpan.org/pod/DateTime#$dt-%3Eymd($optional_separator),-$dt-%3Emdy(...),-$dt-%3Edmy(...)
+            return $data->ymd;
+        }
+        return $data .q();
+    } elsif ($type eq 'DATE_TIME') {
+        # the date-time notation as defined by RFC 3339, section 5.6, for example, 2017-07-21T17:32:28Z
+        if (ref($data) eq 'DateTime') {
+            # https://metacpan.org/pod/DateTime#$dt-%3Erfc3339
+            return $data->rfc3339;
+        }
+        return $data .q();
+    }
+}
+
 # from Perl hashref
 sub from_hash {
    my ($self, $hash) = @_;
@@ -144,10 +191,14 @@ sub _deserialize {
    my ($self, $type, $data) = @_;
    $log->debugf("deserializing %s with %s",Dumper($data), $type);

-    if ($type eq 'DateTime') {
+    if (grep( /^$type$/ , ('DATE_TIME', 'DATE'))) {
        return DateTime->from_epoch(epoch => str2time($data));
-    } elsif ( grep( /^$type$/, ('int', 'double', 'string', 'boolean'))) {
-        return $data;
+    } elsif ( grep( /^$type$/, ('int', 'double'))) {
+        return $data + 0;
+    } elsif ($type eq 'string') {
+        return $data . q();
+    } elsif ($type eq 'boolean') {
+        return !!$data;
    } else { # hash(model)
        my $_instance = eval "WWW::OpenAPIClient::Object::$type->new()";
        return $_instance->from_hash($data);
--- a/samples/client/petstore/perl/lib/WWW/OpenAPIClient/Object/Pet.pm
+++ b/samples/client/petstore/perl/lib/WWW/OpenAPIClient/Object/Pet.pm
@@ -102,13 +102,60 @@ sub TO_JSON {
    my $_data = {};
    foreach my $_key (keys %{$self->attribute_map}) {
        if (defined $self->{$_key}) {
-            $_data->{$self->attribute_map->{$_key}} = $self->{$_key};
+            my $_json_attribute = $self->attribute_map->{$_key};
+            my $_type = $self->openapi_types->{$_key};
+            my $_value = $self->{$_key};
+            if ($_type =~ /^array\[(.+)\]$/i) { # array
+                my $_subclass = $1;
+                $_data->{$_json_attribute} =  [ map { $self->_to_json_primitives($_subclass, $_) } @$_value ];
+            } elsif ($_type =~ /^hash\[string,(.+)\]$/i) { # hash
+                my $_subclass = $1;
+                my %_hash = ();
+                while (my($_key, $_element) = each %{$_value}) {
+                    $_hash{$_key} = $self->_to_json_primitives($_subclass, $_element);
+                }
+                $_data->{$_json_attribute} = \%_hash;
+            } elsif ( grep( /^$_type$/, ('int', 'double', 'string', 'boolean', 'DATE', 'DATE_TIME'))) {
+                $_data->{$_json_attribute} = $self->_to_json_primitives($_type, $_value);
+            } else {
+                $_data->{$_json_attribute} = $_value;
+            }
        }
    }

    return $_data;
 }

+# to_json non-array data
+sub _to_json_primitives {
+    my ($self, $type, $data) = @_;
+    if ( grep( /^$type$/, ('int', 'double'))) {
+        # https://metacpan.org/pod/JSON#simple-scalars
+        # numify it, ensuring it will be dumped as a number
+        return $data + 0;
+    } elsif ($type eq 'string') {
+        # https://metacpan.org/pod/JSON#simple-scalars
+        # stringified
+        return $data . q();
+    } elsif ($type eq 'boolean') {
+        # https://metacpan.org/pod/JSON#JSON::true,-JSON::false,-JSON::null
+        return $data ? \1 : \0;
+    } elsif ($type eq 'DATE') {
+        if (ref($data) eq 'DateTime') {
+            # https://metacpan.org/pod/DateTime#$dt-%3Eymd($optional_separator),-$dt-%3Emdy(...),-$dt-%3Edmy(...)
+            return $data->ymd;
+        }
+        return $data .q();
+    } elsif ($type eq 'DATE_TIME') {
+        # the date-time notation as defined by RFC 3339, section 5.6, for example, 2017-07-21T17:32:28Z
+        if (ref($data) eq 'DateTime') {
+            # https://metacpan.org/pod/DateTime#$dt-%3Erfc3339
+            return $data->rfc3339;
+        }
+        return $data .q();
+    }
+}
+
 # from Perl hashref
 sub from_hash {
    my ($self, $hash) = @_;
@@ -145,10 +192,14 @@ sub _deserialize {
    my ($self, $type, $data) = @_;
    $log->debugf("deserializing %s with %s",Dumper($data), $type);

-    if ($type eq 'DateTime') {
+    if (grep( /^$type$/ , ('DATE_TIME', 'DATE'))) {
        return DateTime->from_epoch(epoch => str2time($data));
-    } elsif ( grep( /^$type$/, ('int', 'double', 'string', 'boolean'))) {
-        return $data;
+    } elsif ( grep( /^$type$/, ('int', 'double'))) {
+        return $data + 0;
+    } elsif ($type eq 'string') {
+        return $data . q();
+    } elsif ($type eq 'boolean') {
+        return !!$data;
    } else { # hash(model)
        my $_instance = eval "WWW::OpenAPIClient::Object::$type->new()";
        return $_instance->from_hash($data);
--- a/samples/client/petstore/perl/lib/WWW/OpenAPIClient/Object/ReadOnlyFirst.pm
+++ b/samples/client/petstore/perl/lib/WWW/OpenAPIClient/Object/ReadOnlyFirst.pm
@@ -100,13 +100,60 @@ sub TO_JSON {
    my $_data = {};
    foreach my $_key (keys %{$self->attribute_map}) {
        if (defined $self->{$_key}) {
-            $_data->{$self->attribute_map->{$_key}} = $self->{$_key};
+            my $_json_attribute = $self->attribute_map->{$_key};
+            my $_type = $self->openapi_types->{$_key};
+            my $_value = $self->{$_key};
+            if ($_type =~ /^array\[(.+)\]$/i) { # array
+                my $_subclass = $1;
+                $_data->{$_json_attribute} =  [ map { $self->_to_json_primitives($_subclass, $_) } @$_value ];
+            } elsif ($_type =~ /^hash\[string,(.+)\]$/i) { # hash
+                my $_subclass = $1;
+                my %_hash = ();
+                while (my($_key, $_element) = each %{$_value}) {
+                    $_hash{$_key} = $self->_to_json_primitives($_subclass, $_element);
+                }
+                $_data->{$_json_attribute} = \%_hash;
+            } elsif ( grep( /^$_type$/, ('int', 'double', 'string', 'boolean', 'DATE', 'DATE_TIME'))) {
+                $_data->{$_json_attribute} = $self->_to_json_primitives($_type, $_value);
+            } else {
+                $_data->{$_json_attribute} = $_value;
+            }
        }
    }

    return $_data;
 }

+# to_json non-array data
+sub _to_json_primitives {
+    my ($self, $type, $data) = @_;
+    if ( grep( /^$type$/, ('int', 'double'))) {
+        # https://metacpan.org/pod/JSON#simple-scalars
+        # numify it, ensuring it will be dumped as a number
+        return $data + 0;
+    } elsif ($type eq 'string') {
+        # https://metacpan.org/pod/JSON#simple-scalars
+        # stringified
+        return $data . q();
+    } elsif ($type eq 'boolean') {
+        # https://metacpan.org/pod/JSON#JSON::true,-JSON::false,-JSON::null
+        return $data ? \1 : \0;
+    } elsif ($type eq 'DATE') {
+        if (ref($data) eq 'DateTime') {
+            # https://metacpan.org/pod/DateTime#$dt-%3Eymd($optional_separator),-$dt-%3Emdy(...),-$dt-%3Edmy(...)
+            return $data->ymd;
+        }
+        return $data .q();
+    } elsif ($type eq 'DATE_TIME') {
+        # the date-time notation as defined by RFC 3339, section 5.6, for example, 2017-07-21T17:32:28Z
+        if (ref($data) eq 'DateTime') {
+            # https://metacpan.org/pod/DateTime#$dt-%3Erfc3339
+            return $data->rfc3339;
+        }
+        return $data .q();
+    }
+}
+
 # from Perl hashref
 sub from_hash {
    my ($self, $hash) = @_;
@@ -143,10 +190,14 @@ sub _deserialize {
    my ($self, $type, $data) = @_;
    $log->debugf("deserializing %s with %s",Dumper($data), $type);

-    if ($type eq 'DateTime') {
+    if (grep( /^$type$/ , ('DATE_TIME', 'DATE'))) {
        return DateTime->from_epoch(epoch => str2time($data));
-    } elsif ( grep( /^$type$/, ('int', 'double', 'string', 'boolean'))) {
-        return $data;
+    } elsif ( grep( /^$type$/, ('int', 'double'))) {
+        return $data + 0;
+    } elsif ($type eq 'string') {
+        return $data . q();
+    } elsif ($type eq 'boolean') {
+        return !!$data;
    } else { # hash(model)
        my $_instance = eval "WWW::OpenAPIClient::Object::$type->new()";
        return $_instance->from_hash($data);
--- a/samples/client/petstore/perl/lib/WWW/OpenAPIClient/Object/SingleRefType.pm
+++ b/samples/client/petstore/perl/lib/WWW/OpenAPIClient/Object/SingleRefType.pm
@@ -100,13 +100,60 @@ sub TO_JSON {
    my $_data = {};
    foreach my $_key (keys %{$self->attribute_map}) {
        if (defined $self->{$_key}) {
-            $_data->{$self->attribute_map->{$_key}} = $self->{$_key};
+            my $_json_attribute = $self->attribute_map->{$_key};
+            my $_type = $self->openapi_types->{$_key};
+            my $_value = $self->{$_key};
+            if ($_type =~ /^array\[(.+)\]$/i) { # array
+                my $_subclass = $1;
+                $_data->{$_json_attribute} =  [ map { $self->_to_json_primitives($_subclass, $_) } @$_value ];
+            } elsif ($_type =~ /^hash\[string,(.+)\]$/i) { # hash
+                my $_subclass = $1;
+                my %_hash = ();
+                while (my($_key, $_element) = each %{$_value}) {
+                    $_hash{$_key} = $self->_to_json_primitives($_subclass, $_element);
+                }
+                $_data->{$_json_attribute} = \%_hash;
+            } elsif ( grep( /^$_type$/, ('int', 'double', 'string', 'boolean', 'DATE', 'DATE_TIME'))) {
+                $_data->{$_json_attribute} = $self->_to_json_primitives($_type, $_value);
+            } else {
+                $_data->{$_json_attribute} = $_value;
+            }
        }
    }

    return $_data;
 }

+# to_json non-array data
+sub _to_json_primitives {
+    my ($self, $type, $data) = @_;
+    if ( grep( /^$type$/, ('int', 'double'))) {
+        # https://metacpan.org/pod/JSON#simple-scalars
+        # numify it, ensuring it will be dumped as a number
+        return $data + 0;
+    } elsif ($type eq 'string') {
+        # https://metacpan.org/pod/JSON#simple-scalars
+        # stringified
+        return $data . q();
+    } elsif ($type eq 'boolean') {
+        # https://metacpan.org/pod/JSON#JSON::true,-JSON::false,-JSON::null
+        return $data ? \1 : \0;
+    } elsif ($type eq 'DATE') {
+        if (ref($data) eq 'DateTime') {
+            # https://metacpan.org/pod/DateTime#$dt-%3Eymd($optional_separator),-$dt-%3Emdy(...),-$dt-%3Edmy(...)
+            return $data->ymd;
+        }
+        return $data .q();
+    } elsif ($type eq 'DATE_TIME') {
+        # the date-time notation as defined by RFC 3339, section 5.6, for example, 2017-07-21T17:32:28Z
+        if (ref($data) eq 'DateTime') {
+            # https://metacpan.org/pod/DateTime#$dt-%3Erfc3339
+            return $data->rfc3339;
+        }
+        return $data .q();
+    }
+}
+
 # from Perl hashref
 sub from_hash {
    my ($self, $hash) = @_;
@@ -143,10 +190,14 @@ sub _deserialize {
    my ($self, $type, $data) = @_;
    $log->debugf("deserializing %s with %s",Dumper($data), $type);

-    if ($type eq 'DateTime') {
+    if (grep( /^$type$/ , ('DATE_TIME', 'DATE'))) {
        return DateTime->from_epoch(epoch => str2time($data));
-    } elsif ( grep( /^$type$/, ('int', 'double', 'string', 'boolean'))) {
-        return $data;
+    } elsif ( grep( /^$type$/, ('int', 'double'))) {
+        return $data + 0;
+    } elsif ($type eq 'string') {
+        return $data . q();
+    } elsif ($type eq 'boolean') {
+        return !!$data;
    } else { # hash(model)
        my $_instance = eval "WWW::OpenAPIClient::Object::$type->new()";
        return $_instance->from_hash($data);
--- a/samples/client/petstore/perl/lib/WWW/OpenAPIClient/Object/SpecialModelName.pm
+++ b/samples/client/petstore/perl/lib/WWW/OpenAPIClient/Object/SpecialModelName.pm
@@ -100,13 +100,60 @@ sub TO_JSON {
    my $_data = {};
    foreach my $_key (keys %{$self->attribute_map}) {
        if (defined $self->{$_key}) {
-            $_data->{$self->attribute_map->{$_key}} = $self->{$_key};
+            my $_json_attribute = $self->attribute_map->{$_key};
+            my $_type = $self->openapi_types->{$_key};
+            my $_value = $self->{$_key};
+            if ($_type =~ /^array\[(.+)\]$/i) { # array
+                my $_subclass = $1;
+                $_data->{$_json_attribute} =  [ map { $self->_to_json_primitives($_subclass, $_) } @$_value ];
+            } elsif ($_type =~ /^hash\[string,(.+)\]$/i) { # hash
+                my $_subclass = $1;
+                my %_hash = ();
+                while (my($_key, $_element) = each %{$_value}) {
+                    $_hash{$_key} = $self->_to_json_primitives($_subclass, $_element);
+                }
+                $_data->{$_json_attribute} = \%_hash;
+            } elsif ( grep( /^$_type$/, ('int', 'double', 'string', 'boolean', 'DATE', 'DATE_TIME'))) {
+                $_data->{$_json_attribute} = $self->_to_json_primitives($_type, $_value);
+            } else {
+                $_data->{$_json_attribute} = $_value;
+            }
        }
    }

    return $_data;
 }

+# to_json non-array data
+sub _to_json_primitives {
+    my ($self, $type, $data) = @_;
+    if ( grep( /^$type$/, ('int', 'double'))) {
+        # https://metacpan.org/pod/JSON#simple-scalars
+        # numify it, ensuring it will be dumped as a number
+        return $data + 0;
+    } elsif ($type eq 'string') {
+        # https://metacpan.org/pod/JSON#simple-scalars
+        # stringified
+        return $data . q();
+    } elsif ($type eq 'boolean') {
+        # https://metacpan.org/pod/JSON#JSON::true,-JSON::false,-JSON::null
+        return $data ? \1 : \0;
+    } elsif ($type eq 'DATE') {
+        if (ref($data) eq 'DateTime') {
+            # https://metacpan.org/pod/DateTime#$dt-%3Eymd($optional_separator),-$dt-%3Emdy(...),-$dt-%3Edmy(...)
+            return $data->ymd;
+        }
+        return $data .q();
+    } elsif ($type eq 'DATE_TIME') {
+        # the date-time notation as defined by RFC 3339, section 5.6, for example, 2017-07-21T17:32:28Z
+        if (ref($data) eq 'DateTime') {
+            # https://metacpan.org/pod/DateTime#$dt-%3Erfc3339
+            return $data->rfc3339;
+        }
+        return $data .q();
+    }
+}
+
 # from Perl hashref
 sub from_hash {
    my ($self, $hash) = @_;
@@ -143,10 +190,14 @@ sub _deserialize {
    my ($self, $type, $data) = @_;
    $log->debugf("deserializing %s with %s",Dumper($data), $type);

-    if ($type eq 'DateTime') {
+    if (grep( /^$type$/ , ('DATE_TIME', 'DATE'))) {
        return DateTime->from_epoch(epoch => str2time($data));
-    } elsif ( grep( /^$type$/, ('int', 'double', 'string', 'boolean'))) {
-        return $data;
+    } elsif ( grep( /^$type$/, ('int', 'double'))) {
+        return $data + 0;
+    } elsif ($type eq 'string') {
+        return $data . q();
+    } elsif ($type eq 'boolean') {
+        return !!$data;
    } else { # hash(model)
        my $_instance = eval "WWW::OpenAPIClient::Object::$type->new()";
        return $_instance->from_hash($data);
--- a/samples/client/petstore/perl/lib/WWW/OpenAPIClient/Object/Tag.pm
+++ b/samples/client/petstore/perl/lib/WWW/OpenAPIClient/Object/Tag.pm
@@ -100,13 +100,60 @@ sub TO_JSON {
    my $_data = {};
    foreach my $_key (keys %{$self->attribute_map}) {
        if (defined $self->{$_key}) {
-            $_data->{$self->attribute_map->{$_key}} = $self->{$_key};
+            my $_json_attribute = $self->attribute_map->{$_key};
+            my $_type = $self->openapi_types->{$_key};
+            my $_value = $self->{$_key};
+            if ($_type =~ /^array\[(.+)\]$/i) { # array
+                my $_subclass = $1;
+                $_data->{$_json_attribute} =  [ map { $self->_to_json_primitives($_subclass, $_) } @$_value ];
+            } elsif ($_type =~ /^hash\[string,(.+)\]$/i) { # hash
+                my $_subclass = $1;
+                my %_hash = ();
+                while (my($_key, $_element) = each %{$_value}) {
+                    $_hash{$_key} = $self->_to_json_primitives($_subclass, $_element);
+                }
+                $_data->{$_json_attribute} = \%_hash;
+            } elsif ( grep( /^$_type$/, ('int', 'double', 'string', 'boolean', 'DATE', 'DATE_TIME'))) {
+                $_data->{$_json_attribute} = $self->_to_json_primitives($_type, $_value);
+            } else {
+                $_data->{$_json_attribute} = $_value;
+            }
        }
    }

    return $_data;
 }

+# to_json non-array data
+sub _to_json_primitives {
+    my ($self, $type, $data) = @_;
+    if ( grep( /^$type$/, ('int', 'double'))) {
+        # https://metacpan.org/pod/JSON#simple-scalars
+        # numify it, ensuring it will be dumped as a number
+        return $data + 0;
+    } elsif ($type eq 'string') {
+        # https://metacpan.org/pod/JSON#simple-scalars
+        # stringified
+        return $data . q();
+    } elsif ($type eq 'boolean') {
+        # https://metacpan.org/pod/JSON#JSON::true,-JSON::false,-JSON::null
+        return $data ? \1 : \0;
+    } elsif ($type eq 'DATE') {
+        if (ref($data) eq 'DateTime') {
+            # https://metacpan.org/pod/DateTime#$dt-%3Eymd($optional_separator),-$dt-%3Emdy(...),-$dt-%3Edmy(...)
+            return $data->ymd;
+        }
+        return $data .q();
+    } elsif ($type eq 'DATE_TIME') {
+        # the date-time notation as defined by RFC 3339, section 5.6, for example, 2017-07-21T17:32:28Z
+        if (ref($data) eq 'DateTime') {
+            # https://metacpan.org/pod/DateTime#$dt-%3Erfc3339
+            return $data->rfc3339;
+        }
+        return $data .q();
+    }
+}
+
 # from Perl hashref
 sub from_hash {
    my ($self, $hash) = @_;
@@ -143,10 +190,14 @@ sub _deserialize {
    my ($self, $type, $data) = @_;
    $log->debugf("deserializing %s with %s",Dumper($data), $type);

-    if ($type eq 'DateTime') {
+    if (grep( /^$type$/ , ('DATE_TIME', 'DATE'))) {
        return DateTime->from_epoch(epoch => str2time($data));
-    } elsif ( grep( /^$type$/, ('int', 'double', 'string', 'boolean'))) {
-        return $data;
+    } elsif ( grep( /^$type$/, ('int', 'double'))) {
+        return $data + 0;
+    } elsif ($type eq 'string') {
+        return $data . q();
+    } elsif ($type eq 'boolean') {
+        return !!$data;
    } else { # hash(model)
        my $_instance = eval "WWW::OpenAPIClient::Object::$type->new()";
        return $_instance->from_hash($data);
--- a/samples/client/petstore/perl/lib/WWW/OpenAPIClient/Object/User.pm
+++ b/samples/client/petstore/perl/lib/WWW/OpenAPIClient/Object/User.pm
@@ -100,13 +100,60 @@ sub TO_JSON {
    my $_data = {};
    foreach my $_key (keys %{$self->attribute_map}) {
        if (defined $self->{$_key}) {
-            $_data->{$self->attribute_map->{$_key}} = $self->{$_key};
+            my $_json_attribute = $self->attribute_map->{$_key};
+            my $_type = $self->openapi_types->{$_key};
+            my $_value = $self->{$_key};
+            if ($_type =~ /^array\[(.+)\]$/i) { # array
+                my $_subclass = $1;
+                $_data->{$_json_attribute} =  [ map { $self->_to_json_primitives($_subclass, $_) } @$_value ];
+            } elsif ($_type =~ /^hash\[string,(.+)\]$/i) { # hash
+                my $_subclass = $1;
+                my %_hash = ();
+                while (my($_key, $_element) = each %{$_value}) {
+                    $_hash{$_key} = $self->_to_json_primitives($_subclass, $_element);
+                }
+                $_data->{$_json_attribute} = \%_hash;
+            } elsif ( grep( /^$_type$/, ('int', 'double', 'string', 'boolean', 'DATE', 'DATE_TIME'))) {
+                $_data->{$_json_attribute} = $self->_to_json_primitives($_type, $_value);
+            } else {
+                $_data->{$_json_attribute} = $_value;
+            }
        }
    }

    return $_data;
 }

+# to_json non-array data
+sub _to_json_primitives {
+    my ($self, $type, $data) = @_;
+    if ( grep( /^$type$/, ('int', 'double'))) {
+        # https://metacpan.org/pod/JSON#simple-scalars
+        # numify it, ensuring it will be dumped as a number
+        return $data + 0;
+    } elsif ($type eq 'string') {
+        # https://metacpan.org/pod/JSON#simple-scalars
+        # stringified
+        return $data . q();
+    } elsif ($type eq 'boolean') {
+        # https://metacpan.org/pod/JSON#JSON::true,-JSON::false,-JSON::null
+        return $data ? \1 : \0;
+    } elsif ($type eq 'DATE') {
+        if (ref($data) eq 'DateTime') {
+            # https://metacpan.org/pod/DateTime#$dt-%3Eymd($optional_separator),-$dt-%3Emdy(...),-$dt-%3Edmy(...)
+            return $data->ymd;
+        }
+        return $data .q();
+    } elsif ($type eq 'DATE_TIME') {
+        # the date-time notation as defined by RFC 3339, section 5.6, for example, 2017-07-21T17:32:28Z
+        if (ref($data) eq 'DateTime') {
+            # https://metacpan.org/pod/DateTime#$dt-%3Erfc3339
+            return $data->rfc3339;
+        }
+        return $data .q();
+    }
+}
+
 # from Perl hashref
 sub from_hash {
    my ($self, $hash) = @_;
@@ -143,10 +190,14 @@ sub _deserialize {
    my ($self, $type, $data) = @_;
    $log->debugf("deserializing %s with %s",Dumper($data), $type);

-    if ($type eq 'DateTime') {
+    if (grep( /^$type$/ , ('DATE_TIME', 'DATE'))) {
        return DateTime->from_epoch(epoch => str2time($data));
-    } elsif ( grep( /^$type$/, ('int', 'double', 'string', 'boolean'))) {
-        return $data;
+    } elsif ( grep( /^$type$/, ('int', 'double'))) {
+        return $data + 0;
+    } elsif ($type eq 'string') {
+        return $data . q();
+    } elsif ($type eq 'boolean') {
+        return !!$data;
    } else { # hash(model)
        my $_instance = eval "WWW::OpenAPIClient::Object::$type->new()";
        return $_instance->from_hash($data);
--- a/samples/client/petstore/perl/tests/02_store_api.t
+++ b/samples/client/petstore/perl/tests/02_store_api.t
@@ -1,4 +1,4 @@
-use Test::More tests => 41;
+use Test::More tests => 52;
 use Test::Exception;

 use lib 'lib';
@@ -13,6 +13,7 @@ use_ok('WWW::OpenAPIClient::Object::Pet');
 use_ok('WWW::OpenAPIClient::Object::Tag');
 use_ok('WWW::OpenAPIClient::Object::Category');
 use_ok('WWW::OpenAPIClient::Object::User');
+use_ok('WWW::OpenAPIClient::Object::Order');


 my $api_client = WWW::OpenAPIClient::ApiClient->new();
@@ -28,7 +29,7 @@ like ($get_inventory_response->{sold}, qr/^\d+$/, "sold is numeric");

 my $pet_json = <<JSON;
 {
-    "pet": { 
+    "pet": {
        "id": 0,
        "category": {
            "id": 0,
@@ -60,7 +61,7 @@ is $api_client->deserialize("HASH[string,Pet]", $pet_json)->{pet}->{photo_urls}-

 my $array_json = <<JSON;
 [
-    { 
+    {
        "id": 0,
        "category": {
            "id": 0,
@@ -120,9 +121,8 @@ is ref $api_client->deserialize("Pet", $pet_json_nopet)->{tags}->[0], "WWW::Open
 is $api_client->deserialize("Pet", $pet_json_nopet)->{tags}->[0]->{name}, "tag string", "get the tag name the Pet object";
 is $api_client->deserialize("Pet", $pet_json_nopet)->{photo_urls}->[0], "string", "get the photoUrl from the Pet object";

-
 my %userdata = (
-	id => 4000, 
+	id => "4000",
 	username => "tony",
    firstName => "Tony",
    lastName => "Tiger",
@@ -131,7 +131,7 @@ my %userdata = (
    phone => "408-867-5309",
    userStatus => 1,
    );
-      
+
 my $user = WWW::OpenAPIClient::Object::User->new->from_hash(\%userdata);
 is ref $user, 'WWW::OpenAPIClient::Object::User', "built a User object via from_hash()";
 is $user->{id}, $userdata{id}, "got the id of the User object";
@@ -143,4 +143,31 @@ is $user->{password}, $userdata{password}, "got the password of the User object"
 is $user->{phone}, $userdata{phone}, "got the phone of the User object";
 is $user->{user_status}, $userdata{userStatus}, "got the userStatus of the User object";

+my $user_to_json = JSON->new->convert_blessed->encode($user);
+like $user_to_json, qr/4000/, '$userdata{id} is string. But, json id is a number';
+unlike $user_to_json, qr/"4000"/, '$userdata{id} is string. But, json id is a number';

+
+my %order_data = (
+    id       => '123',
+    petId    => '456',
+    quantity => 789,
+    shipDate => '2020-11-06T09:20:48Z',
+    status   => 101112, # status type is string, but this data is number 
+    complete => 0, # status type is boolean, but this data is number
+);
+my $order = WWW::OpenAPIClient::Object::Order->new->from_hash(\%order_data);
+is ref($order->ship_date), 'DateTime';
+
+my $order_to_json = JSON->new->convert_blessed->encode($order);
+like $order_to_json, qr/123/, '$order{id} is string. But, json type is number';
+unlike $order_to_json, qr/"123"/, '$order{id} is string. But, json type is number';
+
+like $order_to_json, qr/789/, '$order{quantity} is number';
+unlike $order_to_json, qr/"789"/, '$order{quantity} is number';
+
+like $order_to_json, qr/2020-11-06T09:20:48Z/, '$order{shipDate} to date-time format';
+
+like $order_to_json, qr/"101112"/, '$order{status} is number. But json type is string';
+
+like $order_to_json, qr/false/, '$order{complete} is number. But json type is boolean';