[TS-FETCH] Generate models/index.ts in postProcessModels (#18256)

* [TS-FETCH] Generate models.index in postProcessModels

* [TS-FETCH] Add test for spec without path

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/TypeScriptFetchClientCodegen.java

@@ -340,6 +340,12 @@ public class TypeScriptFetchClientCodegen extends AbstractTypeScriptClientCodege
             this.processCodeGenModel(cm);
         }
 
+        // Add supporting file only if we plan to generate files in /models
+        if (!objs.isEmpty() && !addedModelIndex) {
+            addedModelIndex = true;
+            supportingFiles.add(new SupportingFile("models.index.mustache", modelPackage().replace('.', File.separatorChar), "index.ts"));
+        }
+
         return objs;
     }
 

modules/openapi-generator/src/test/java/org/openapitools/codegen/typescript/fetch/TypeScriptFetchClientCodegenTest.java

@@ -6,8 +6,12 @@ import io.swagger.v3.oas.models.media.ArraySchema;
 import io.swagger.v3.oas.models.media.MapSchema;
 import io.swagger.v3.oas.models.media.Schema;
 import io.swagger.v3.oas.models.media.StringSchema;
+import org.openapitools.codegen.config.CodegenConfigurator;
+import org.openapitools.codegen.ClientOptInput;
 import org.openapitools.codegen.CodegenConstants;
 import org.openapitools.codegen.CodegenOperation;
+import org.openapitools.codegen.DefaultGenerator;
+import org.openapitools.codegen.Generator;
 import org.openapitools.codegen.SupportingFile;
 import org.openapitools.codegen.TestUtils;
 import org.openapitools.codegen.languages.AbstractTypeScriptClientCodegen;
@@ -17,6 +21,14 @@ import org.openapitools.codegen.utils.ModelUtils;
 import org.testng.Assert;
 import org.testng.annotations.Test;
 
+import java.io.File;
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Paths;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
 import static org.assertj.core.api.Assertions.assertThat;
 
 @Test(groups = {TypeScriptGroups.TYPESCRIPT, TypeScriptGroups.TYPESCRIPT_FETCH})
@@ -55,6 +67,32 @@ public class TypeScriptFetchClientCodegenTest {
         Assert.assertEquals(operation.isResponseOptional, true);
     }
 
+    @Test
+    public void testModelsWithoutPaths() throws IOException {
+        final String specPath = "src/test/resources/3_1/reusable-components-without-paths.yaml";
+
+        Map<String, Object> properties = new HashMap<>();
+        properties.put("supportsES6", true);
+
+        File output = Files.createTempDirectory("test").toFile();
+        output.deleteOnExit();
+
+        final CodegenConfigurator configurator = new CodegenConfigurator()
+                .setGeneratorName("typescript-fetch")
+                .setInputSpec(specPath)
+                .setAdditionalProperties(properties)
+                .setOutputDir(output.getAbsolutePath().replace("\\", "/"));
+
+        Generator generator = new DefaultGenerator();
+        List<File> files = generator.opts(configurator.toClientOptInput()).generate();
+        files.forEach(File::deleteOnExit);
+
+        TestUtils.assertFileExists(Paths.get(output + "/index.ts"));
+        TestUtils.assertFileExists(Paths.get(output + "/runtime.ts"));
+        TestUtils.assertFileExists(Paths.get(output + "/models/Pet.ts"));
+        TestUtils.assertFileExists(Paths.get(output + "/models/index.ts"));
+    }
+
     @Test
     public void testWithoutSnapshotVersion() {
         OpenAPI api = TestUtils.createOpenAPI();

modules/openapi-generator/src/test/resources/3_1/reusable-components-without-paths.yaml

@@ -0,0 +1,19 @@
+openapi: 3.1.0
+info:
+  title: Reusable components without paths example
+  version: 1.0.0
+# Since OAS 3.1.0 the paths element isn't necessary. Now a valid OpenAPI Document can describe only paths, webhooks, or even only reusable components
+components:
+  schemas:
+    Pet:
+      required:
+        - id
+        - name
+      properties:
+        id:
+          type: integer
+          format: int64
+        name:
+          type: string
+        tag:
+          type: string