add more tests such as empty response (#14587)

samples/client/echo_api/java/feign-gson/src/main/java/org/openapitools/client/api/BodyApi.java

@@ -44,4 +44,33 @@ public interface BodyApi extends ApiClient.Api {
   ApiResponse<Pet> testEchoBodyPetWithHttpInfo(Pet pet);
 
 
+
+  /**
+   * Test empty response body
+   * Test empty response body
+   * @param pet Pet object that needs to be added to the store (optional)
+   * @return String
+   */
+  @RequestLine("POST /echo/body/Pet/response_string")
+  @Headers({
+    "Content-Type: application/json",
+    "Accept: text/plain",
+  })
+  String testEchoBodyPetResponseString(Pet pet);
+
+  /**
+   * Test empty response body
+   * Similar to <code>testEchoBodyPetResponseString</code> but it also returns the http response headers .
+   * Test empty response body
+   * @param pet Pet object that needs to be added to the store (optional)
+   * @return A ApiResponse that wraps the response boyd and the http headers.
+   */
+  @RequestLine("POST /echo/body/Pet/response_string")
+  @Headers({
+    "Content-Type: application/json",
+    "Accept: text/plain",
+  })
+  ApiResponse<String> testEchoBodyPetResponseStringWithHttpInfo(Pet pet);
+
+
 }

samples/client/echo_api/java/feign-gson/src/main/java/org/openapitools/client/api/FormApi.java

@@ -0,0 +1,50 @@
+package org.openapitools.client.api;
+
+import org.openapitools.client.ApiClient;
+import org.openapitools.client.EncodingUtils;
+import org.openapitools.client.model.ApiResponse;
+
+
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import feign.*;
+
+@javax.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen")
+public interface FormApi extends ApiClient.Api {
+
+
+  /**
+   * Test form parameter(s)
+   * Test form parameter(s)
+   * @param integerForm  (optional)
+   * @param booleanForm  (optional)
+   * @param stringForm  (optional)
+   * @return String
+   */
+  @RequestLine("POST /form/integer/boolean/string")
+  @Headers({
+    "Content-Type: application/x-www-form-urlencoded",
+    "Accept: text/plain",
+  })
+  String testFormIntegerBooleanString(@Param("integer_form") Integer integerForm, @Param("boolean_form") Boolean booleanForm, @Param("string_form") String stringForm);
+
+  /**
+   * Test form parameter(s)
+   * Similar to <code>testFormIntegerBooleanString</code> but it also returns the http response headers .
+   * Test form parameter(s)
+   * @param integerForm  (optional)
+   * @param booleanForm  (optional)
+   * @param stringForm  (optional)
+   * @return A ApiResponse that wraps the response boyd and the http headers.
+   */
+  @RequestLine("POST /form/integer/boolean/string")
+  @Headers({
+    "Content-Type: application/x-www-form-urlencoded",
+    "Accept: text/plain",
+  })
+  ApiResponse<String> testFormIntegerBooleanStringWithHttpInfo(@Param("integer_form") Integer integerForm, @Param("boolean_form") Boolean booleanForm, @Param("string_form") String stringForm);
+
+
+}

samples/client/echo_api/java/feign-gson/src/main/java/org/openapitools/client/api/HeaderApi.java

@@ -0,0 +1,58 @@
+package org.openapitools.client.api;
+
+import org.openapitools.client.ApiClient;
+import org.openapitools.client.EncodingUtils;
+import org.openapitools.client.model.ApiResponse;
+
+
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import feign.*;
+
+@javax.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen")
+public interface HeaderApi extends ApiClient.Api {
+
+
+  /**
+   * Test header parameter(s)
+   * Test header parameter(s)
+   * @param integerHeader  (optional)
+   * @param booleanHeader  (optional)
+   * @param stringHeader  (optional)
+   * @return String
+   */
+  @RequestLine("GET /header/integer/boolean/string")
+  @Headers({
+    "Accept: text/plain",
+    "integer_header: {integerHeader}",
+    
+    "boolean_header: {booleanHeader}",
+    
+    "string_header: {stringHeader}"
+  })
+  String testHeaderIntegerBooleanString(@Param("integerHeader") Integer integerHeader, @Param("booleanHeader") Boolean booleanHeader, @Param("stringHeader") String stringHeader);
+
+  /**
+   * Test header parameter(s)
+   * Similar to <code>testHeaderIntegerBooleanString</code> but it also returns the http response headers .
+   * Test header parameter(s)
+   * @param integerHeader  (optional)
+   * @param booleanHeader  (optional)
+   * @param stringHeader  (optional)
+   * @return A ApiResponse that wraps the response boyd and the http headers.
+   */
+  @RequestLine("GET /header/integer/boolean/string")
+  @Headers({
+    "Accept: text/plain",
+    "integer_header: {integerHeader}",
+    
+    "boolean_header: {booleanHeader}",
+    
+    "string_header: {stringHeader}"
+  })
+  ApiResponse<String> testHeaderIntegerBooleanStringWithHttpInfo(@Param("integerHeader") Integer integerHeader, @Param("booleanHeader") Boolean booleanHeader, @Param("stringHeader") String stringHeader);
+
+
+}