Add model name mapping feature to C# codegen (#16209)

* add model name mapping feature to C# codegen

* rename file

* update samples

* update doc

bin/configs/csharp-restsharp-net6.0-name-mappings.yaml

@@ -10,6 +10,9 @@ parameterNameMappings:
   _type: UnderscoreType
   type_: TypeWithUnderscore
   http_debug_operation: HttpDebugOperation
+modelNameMappings:
+  Environment: Env
 additionalProperties:
   packageGuid: '{321C8C3F-0156-40C1-AE42-D59761FB9B6C}'
   hideGenerationTimestamp: "true"
+  targetFramework: net6.0

docs/customization.md

@@ -416,7 +416,16 @@ Here is an example to use `nameMappings` and `parameterNameMapping` in CLI:
 java -jar modules/openapi-generator-cli/target/openapi-generator-cli.jar generate -g java -i modules/openapi-generator/src/test/resources/3_0/java/petstore-with-fake-endpoints-models-for-testing-okhttp-gson.yaml  -o /tmp/java2/ --name-mappings _type=underscoreType, type_=typeWithUnderscore, --parameter-name-mappings _type=paramType, type_=typeParam
 ```
 
-(Not all generators support this feature yet. Please give it a try to confirm the behaviour and open an issue (ticket) to let us know which generators you would like to have this feature enabled and we'll prioritize accordingly.)
+To map model names, use `modelNameMappings` option, e.g.
+```sh
+java -jar modules/openapi-generator-cli/target/openapi-generator-cli.jar generate -g csharp -i modules/openapi-generator/src/test/resources/3_0/petstore.yaml  -o /tmp/csharp/ --model-name-mappings Tag=Label
+```
+will rename the Tag schema to Label instead.
+
+
+(Not all generators support thess features yet. Please give it a try to confirm the behaviour and open an issue (ticket) to let us know which generators you would like to have this feature enabled and we'll prioritize accordingly.)
+
+Related PRs: #16209 (modelNameMappings), #16194, #16206 (nameMappings, parameterNameMappings)
 
 ## Schema Mapping
 

modules/openapi-generator-cli/src/main/java/org/openapitools/codegen/cmd/ConfigHelp.java

@@ -86,6 +86,9 @@ public class ConfigHelp extends OpenApiGeneratorCommand {
     @Option(name = {"--parameter-name-mappings"}, title = "parameter name mappings", description = "displays the parameter name mappings (none)")
     private Boolean parameterNameMappings;
 
+    @Option(name = {"--model-name-mappings"}, title = "model name mappings", description = "displays the model name mappings (none)")
+    private Boolean modelNameMappings;
+
     @Option(name = {"--openapi-normalizer"}, title = "openapi normalizer rules", description = "displays the OpenAPI normalizer rules (none)")
     private Boolean openapiNormalizer;
 
@@ -527,6 +530,18 @@ public class ConfigHelp extends OpenApiGeneratorCommand {
             sb.append(newline);
         }
 
+        if (Boolean.TRUE.equals(modelNameMappings)) {
+            sb.append(newline).append("MODEL NAME MAPPING").append(newline).append(newline);
+            Map<String, String> map = config.modelNameMapping()
+                    .entrySet()
+                    .stream()
+                    .collect(Collectors.toMap(Map.Entry::getKey, Map.Entry::getValue, (a, b) -> {
+                        throw new IllegalStateException(String.format(Locale.ROOT, "Duplicated options! %s and %s", a, b));
+                    }, TreeMap::new));
+            writePlainTextFromMap(sb, map, optIndent, optNestedIndent, "model name", "Mapped to");
+            sb.append(newline);
+        }
+
         if (Boolean.TRUE.equals(openapiNormalizer)) {
             sb.append(newline).append("OPENAPI NORMALIZER RULES").append(newline).append(newline);
             Map<String, String> map = config.openapiNormalizer()

modules/openapi-generator-cli/src/main/java/org/openapitools/codegen/cmd/Generate.java

@@ -202,6 +202,13 @@ public class Generate extends OpenApiGeneratorCommand {
                     + " You can also have multiple occurrences of this option.")
     private List<String> parameterNameMappings = new ArrayList<>();
 
+    @Option(
+            name = {"--model-name-mappings"},
+            title = "model name mappings",
+            description = "specifies mappings between the model name and the new name in the format of model_name=AnotherName,model_name2=OtherName2."
+                    + " You can also have multiple occurrences of this option.")
+    private List<String> modelNameMappings = new ArrayList<>();
+
     @Option(
             name = {"--openapi-normalizer"},
             title = "OpenAPI normalizer rules",
@@ -484,6 +491,7 @@ public class Generate extends OpenApiGeneratorCommand {
         applyInlineSchemaOptionsKvpList(inlineSchemaOptions, configurator);
         applyNameMappingsKvpList(nameMappings, configurator);
         applyParameterNameMappingsKvpList(parameterNameMappings, configurator);
+        applyModelNameMappingsKvpList(modelNameMappings, configurator);
         applyOpenAPINormalizerKvpList(openapiNormalizer, configurator);
         applyTypeMappingsKvpList(typeMappings, configurator);
         applyAdditionalPropertiesKvpList(additionalProperties, configurator);

modules/openapi-generator-core/src/main/java/org/openapitools/codegen/config/GeneratorSettings.java

@@ -55,6 +55,7 @@ public final class GeneratorSettings implements Serializable {
     private final Map<String, String> inlineSchemaOptions;
     private final Map<String, String> nameMappings;
     private final Map<String, String> parameterNameMappings;
+    private final Map<String, String> modelNameMappings;
     private final Map<String, String> openapiNormalizer;
     private final Set<String> languageSpecificPrimitives;
     private final Map<String, String> reservedWordsMappings;
@@ -285,6 +286,15 @@ public final class GeneratorSettings implements Serializable {
         return parameterNameMappings;
     }
 
+    /**
+     * Gets model name mappings between a model name and the new name.
+     *
+     * @return the model name mappings
+     */
+    public Map<String, String> getModelNameMappings() {
+        return modelNameMappings;
+    }
+
     /**
      * Gets OpenAPI normalizer rules
      *
@@ -414,6 +424,7 @@ public final class GeneratorSettings implements Serializable {
         inlineSchemaOptions = Collections.unmodifiableMap(builder.inlineSchemaOptions);
         nameMappings = Collections.unmodifiableMap(builder.nameMappings);
         parameterNameMappings = Collections.unmodifiableMap(builder.parameterNameMappings);
+        modelNameMappings = Collections.unmodifiableMap(builder.modelNameMappings);
         openapiNormalizer = Collections.unmodifiableMap(builder.openapiNormalizer);
         languageSpecificPrimitives = Collections.unmodifiableSet(builder.languageSpecificPrimitives);
         reservedWordsMappings = Collections.unmodifiableMap(builder.reservedWordsMappings);
@@ -490,6 +501,7 @@ public final class GeneratorSettings implements Serializable {
         inlineSchemaOptions = Collections.unmodifiableMap(new HashMap<>(0));
         nameMappings = Collections.unmodifiableMap(new HashMap<>(0));
         parameterNameMappings = Collections.unmodifiableMap(new HashMap<>(0));
+        modelNameMappings = Collections.unmodifiableMap(new HashMap<>(0));
         openapiNormalizer = Collections.unmodifiableMap(new HashMap<>(0));
         languageSpecificPrimitives = Collections.unmodifiableSet(new HashSet<>(0));
         reservedWordsMappings = Collections.unmodifiableMap(new HashMap<>(0));
@@ -557,6 +569,9 @@ public final class GeneratorSettings implements Serializable {
         if (copy.getParameterNameMappings() != null) {
             builder.parameterNameMappings.putAll(copy.getParameterNameMappings());
         }
+        if (copy.getModelNameMappings() != null) {
+            builder.modelNameMappings.putAll(copy.getModelNameMappings());
+        }
         if (copy.getOpenAPINormalizer() != null) {
             builder.openapiNormalizer.putAll(copy.getOpenAPINormalizer());
         }
@@ -604,6 +619,7 @@ public final class GeneratorSettings implements Serializable {
         private Map<String, String> inlineSchemaOptions;
         private Map<String, String> nameMappings;
         private Map<String, String> parameterNameMappings;
+        private Map<String, String> modelNameMappings;
         private Map<String, String> openapiNormalizer;
         private Set<String> languageSpecificPrimitives;
         private Map<String, String> reservedWordsMappings;
@@ -627,6 +643,7 @@ public final class GeneratorSettings implements Serializable {
             inlineSchemaOptions = new HashMap<>();
             nameMappings = new HashMap<>();
             parameterNameMappings = new HashMap<>();
+            modelNameMappings = new HashMap<>();
             openapiNormalizer = new HashMap<>();
             languageSpecificPrimitives = new HashSet<>();
             reservedWordsMappings = new HashMap<>();
@@ -1000,6 +1017,32 @@ public final class GeneratorSettings implements Serializable {
             return this;
         }
 
+        /**
+         * Sets the {@code modelNameMappings} and returns a reference to this Builder so that the methods can be chained together.
+         *
+         * @param modelNameMappings the {@code modelNameMappings} to set
+         * @return a reference to this Builder
+         */
+        public Builder withModelNameMappings(Map<String, String> modelNameMappings) {
+            this.modelNameMappings = modelNameMappings;
+            return this;
+        }
+
+        /**
+         * Sets a single {@code modelNameMappings} and returns a reference to this Builder so that the methods can be chained together.
+         *
+         * @param key   A key for the name mapping
+         * @param value The value of name mapping
+         * @return a reference to this Builder
+         */
+        public Builder withModelNameMapping(String key, String value) {
+            if (this.modelNameMappings == null) {
+                this.modelNameMappings = new HashMap<>();
+            }
+            this.modelNameMappings.put(key, value);
+            return this;
+        }
+
         /**
          * Sets the {@code openapiNormalizer} and returns a reference to this Builder so that the methods can be chained together.
          *
@@ -1216,6 +1259,7 @@ public final class GeneratorSettings implements Serializable {
                 Objects.equals(getInlineSchemaOptions(), that.getInlineSchemaOptions()) &&
                 Objects.equals(getNameMappings(), that.getNameMappings()) &&
                 Objects.equals(getParameterNameMappings(), that.getParameterNameMappings()) &&
+                Objects.equals(getModelNameMappings(), that.getModelNameMappings()) &&
                 Objects.equals(getOpenAPINormalizer(), that.getOpenAPINormalizer()) &&
                 Objects.equals(getLanguageSpecificPrimitives(), that.getLanguageSpecificPrimitives()) &&
                 Objects.equals(getReservedWordsMappings(), that.getReservedWordsMappings()) &&
@@ -1250,6 +1294,7 @@ public final class GeneratorSettings implements Serializable {
                 getInlineSchemaOptions(),
                 getNameMappings(),
                 getParameterNameMappings(),
+                getModelNameMappings(),
                 getOpenAPINormalizer(),
                 getLanguageSpecificPrimitives(),
                 getReservedWordsMappings(),

modules/openapi-generator-gradle-plugin/src/main/kotlin/org/openapitools/generator/gradle/plugin/extensions/OpenApiGeneratorGenerateExtension.kt

@@ -177,6 +177,11 @@ open class OpenApiGeneratorGenerateExtension(project: Project) {
      */
     val parameterNameMappings = project.objects.mapProperty<String, String>()
 
+    /**
+     * Specifies mappings between a model name and the new name
+     */
+    val modelNameMappings = project.objects.mapProperty<String, String>()
+
     /**
      * Specifies mappings (rules) in OpenAPI normalizer
      */

modules/openapi-generator-gradle-plugin/src/main/kotlin/org/openapitools/generator/gradle/plugin/tasks/GenerateTask.kt

@@ -286,6 +286,13 @@ open class GenerateTask @Inject constructor(private val objectFactory: ObjectFac
     @Input
     val parameterNameMappings = project.objects.mapProperty<String, String>()
 
+    /**
+     * Specifies mappings between the model name and the new name
+     */
+    @Optional
+    @Input
+    val modelNameMappings = project.objects.mapProperty<String, String>()
+
     /**
      * Specifies mappings (rules) in OpenAPI normalizer
      */
@@ -833,6 +840,12 @@ open class GenerateTask @Inject constructor(private val objectFactory: ObjectFac
                 }
             }
 
+            if (modelNameMappings.isPresent) {
+                modelNameMappings.get().forEach { entry ->
+                    configurator.addModelNameMapping(entry.key, entry.value)
+                }
+            }
+
             if (openapiNormalizer.isPresent) {
                 openapiNormalizer.get().forEach { entry ->
                     configurator.addOpenAPINormalizer(entry.key, entry.value)

modules/openapi-generator-maven-plugin/src/main/java/org/openapitools/codegen/plugin/CodeGenMojo.java

@@ -344,6 +344,12 @@ public class CodeGenMojo extends AbstractMojo {
     @Parameter(name = "parameterNameMappings", property = "openapi.generator.maven.plugin.parameterNameMappings")
     private List<String> parameterNameMappings;
 
+    /**
+     * A map of model names and the new names
+     */
+    @Parameter(name = "modelNameMappings", property = "openapi.generator.maven.plugin.modelNameMappings")
+    private List<String> modelNameMappings;
+
     /**
      * A set of rules for OpenAPI normalizer
      */
@@ -823,6 +829,11 @@ public class CodeGenMojo extends AbstractMojo {
                 applyParameterNameMappingsKvpList(parameterNameMappings, configurator);
             }
 
+            // Apply Model Name Mappings
+            if (modelNameMappings != null && (configOptions == null || !configOptions.containsKey("model-name-mappings"))) {
+                applyModelNameMappingsKvpList(modelNameMappings, configurator);
+            }
+
             // Apply OpenAPI normalizer rules
             if (openapiNormalizer != null && (configOptions == null || !configOptions.containsKey("openapi-normalizer"))) {
                 applyOpenAPINormalizerKvpList(openapiNormalizer, configurator);

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

@@ -151,6 +151,8 @@ public interface CodegenConfig {
 
     Map<String, String> parameterNameMapping();
 
+    Map<String, String> modelNameMapping();
+
     Map<String, String> openapiNormalizer();
 
     Map<String, String> apiTemplateFiles();

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

@@ -168,6 +168,8 @@ public class DefaultCodegen implements CodegenConfig {
     protected Map<String, String> nameMapping = new HashMap<>();
     // a map to store the mapping between parameter name and the name provided by the user
     protected Map<String, String> parameterNameMapping = new HashMap<>();
+    // a map to store the mapping between model name and the name provided by the user
+    protected Map<String, String> modelNameMapping = new HashMap<>();
     // a map to store the rules in OpenAPI Normalizer
     protected Map<String, String> openapiNormalizer = new HashMap<>();
     protected String modelPackage = "", apiPackage = "", fileSuffix;
@@ -1213,6 +1215,11 @@ public class DefaultCodegen implements CodegenConfig {
         return parameterNameMapping;
     }
 
+    @Override
+    public Map<String, String> modelNameMapping() {
+        return modelNameMapping;
+    }
+
     @Override
     public Map<String, String> openapiNormalizer() {
         return openapiNormalizer;
@@ -2616,6 +2623,11 @@ public class DefaultCodegen implements CodegenConfig {
      */
     @Override
     public String toModelName(final String name) {
+        // obtain the name from modelNameMapping directly if provided
+        if (modelNameMapping.containsKey(name)) {
+            return modelNameMapping.get(name);
+        }
+
         if (schemaKeyToModelNameCache.containsKey(name)) {
             return schemaKeyToModelNameCache.get(name);
         }

modules/openapi-generator/src/main/java/org/openapitools/codegen/config/CodegenConfigurator.java

@@ -73,6 +73,7 @@ public class CodegenConfigurator {
     private Map<String, String> inlineSchemaOptions = new HashMap<>();
     private Map<String, String> nameMappings = new HashMap<>();
     private Map<String, String> parameterNameMappings = new HashMap<>();
+    private Map<String, String> modelNameMappings = new HashMap<>();
     private Map<String, String> openapiNormalizer = new HashMap<>();
     private Set<String> languageSpecificPrimitives = new HashSet<>();
     private Map<String, String> reservedWordsMappings = new HashMap<>();
@@ -132,6 +133,9 @@ public class CodegenConfigurator {
             if(generatorSettings.getParameterNameMappings() != null) {
                 configurator.parameterNameMappings.putAll(generatorSettings.getParameterNameMappings());
             }
+            if(generatorSettings.getModelNameMappings() != null) {
+                configurator.modelNameMappings.putAll(generatorSettings.getModelNameMappings());
+            }
             if(generatorSettings.getOpenAPINormalizer() != null) {
                 configurator.openapiNormalizer.putAll(generatorSettings.getOpenAPINormalizer());
             }
@@ -234,6 +238,12 @@ public class CodegenConfigurator {
         return this;
     }
 
+    public CodegenConfigurator addModelNameMapping(String key, String value) {
+        this.modelNameMappings.put(key, value);
+        generatorSettingsBuilder.withModelNameMapping(key, value);
+        return this;
+    }
+
     public CodegenConfigurator addOpenAPINormalizer(String key, String value) {
         this.openapiNormalizer.put(key, value);
         generatorSettingsBuilder.withOpenAPINormalizer(key, value);
@@ -424,6 +434,12 @@ public class CodegenConfigurator {
         return this;
     }
 
+    public CodegenConfigurator setModelNameMappings(Map<String, String> modelNameMappings) {
+        this.modelNameMappings = modelNameMappings;
+        generatorSettingsBuilder.withModelNameMappings(modelNameMappings);
+        return this;
+    }
+
     public CodegenConfigurator setOpenAPINormalizer(Map<String, String> openapiNormalizer) {
         this.openapiNormalizer = openapiNormalizer;
         generatorSettingsBuilder.withOpenAPINormalizer(openapiNormalizer);
@@ -711,6 +727,7 @@ public class CodegenConfigurator {
         config.inlineSchemaOption().putAll(generatorSettings.getInlineSchemaOptions());
         config.nameMapping().putAll(generatorSettings.getNameMappings());
         config.parameterNameMapping().putAll(generatorSettings.getParameterNameMappings());
+        config.modelNameMapping().putAll(generatorSettings.getModelNameMappings());
         config.openapiNormalizer().putAll(generatorSettings.getOpenAPINormalizer());
         config.languageSpecificPrimitives().addAll(generatorSettings.getLanguageSpecificPrimitives());
         config.reservedWordsMappings().putAll(generatorSettings.getReservedWordsMappings());

modules/openapi-generator/src/main/java/org/openapitools/codegen/config/CodegenConfiguratorUtils.java

@@ -146,6 +146,19 @@ public final class CodegenConfiguratorUtils {
         }
     }
 
+    public static void applyModelNameMappingsKvpList(List<String> modelNameMappings, CodegenConfigurator configurator) {
+        for (String propString : modelNameMappings) {
+            applyModelNameMappingsKvp(propString, configurator);
+        }
+    }
+
+    public static void applyModelNameMappingsKvp(String modelNameMappings, CodegenConfigurator configurator) {
+        final Map<String, String> map = createMapFromKeyValuePairs(modelNameMappings);
+        for (Map.Entry<String, String> entry : map.entrySet()) {
+            configurator.addModelNameMapping(entry.getKey().trim(), entry.getValue().trim());
+        }
+    }
+
     public static void applyOpenAPINormalizerKvpList(List<String> openapiNormalizer, CodegenConfigurator configurator) {
         for (String propString : openapiNormalizer) {
             applyOpenAPINormalizerKvp(propString, configurator);

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

@@ -521,10 +521,10 @@ public abstract class AbstractCSharpCodegen extends DefaultCodegen implements Co
             // GrandparentAnimal has a discriminator, but no oneOf nor anyOf
             // modules\openapi-generator\src\test\resources\3_0\csharp\petstore-with-fake-endpoints-models-for-testing-with-http-signature.yaml
             model.setHasDiscriminatorWithNonEmptyMapping(
-                    ((model.anyOf != null && model.anyOf.size() > 0) || (model.anyOf != null &&model.oneOf.size() > 0)) &&
+                    ((model.anyOf != null && model.anyOf.size() > 0) || (model.anyOf != null && model.oneOf.size() > 0)) &&
-                    model.discriminator != null &&
+                            model.discriminator != null &&
-                    model.discriminator.getMappedModels() != null &&
+                            model.discriminator.getMappedModels() != null &&
-                    model.discriminator.getMappedModels().size() > 0);
+                            model.discriminator.getMappedModels().size() > 0);
 
             if (model.isEnum) {
                 enumRefs.put(model.getClassname(), model);
@@ -539,7 +539,7 @@ public abstract class AbstractCSharpCodegen extends DefaultCodegen implements Co
             if (composedSchemas != null) {
                 List<CodegenProperty> allOf = composedSchemas.getAllOf();
                 if (allOf != null) {
-                    for(CodegenProperty property : allOf) {
+                    for (CodegenProperty property : allOf) {
                         property.name = patchPropertyName(model, property.baseType);
                         patchPropertyVendorExtensinos(property);
                     }
@@ -548,7 +548,7 @@ public abstract class AbstractCSharpCodegen extends DefaultCodegen implements Co
                 List<CodegenProperty> anyOf = composedSchemas.getAnyOf();
                 if (anyOf != null) {
                     removePropertiesDeclaredInComposedTypes(objs, model, anyOf);
-                    for(CodegenProperty property : anyOf) {
+                    for (CodegenProperty property : anyOf) {
                         property.name = patchPropertyName(model, property.baseType);
                         property.isNullable = true;
                         patchPropertyVendorExtensinos(property);
@@ -558,7 +558,7 @@ public abstract class AbstractCSharpCodegen extends DefaultCodegen implements Co
                 List<CodegenProperty> oneOf = composedSchemas.getOneOf();
                 if (oneOf != null) {
                     removePropertiesDeclaredInComposedTypes(objs, model, oneOf);
-                    for(CodegenProperty property : oneOf) {
+                    for (CodegenProperty property : oneOf) {
                         property.name = patchPropertyName(model, property.baseType);
                         property.isNullable = true;
                         patchPropertyVendorExtensinos(property);
@@ -598,10 +598,10 @@ public abstract class AbstractCSharpCodegen extends DefaultCodegen implements Co
     }
 
     /**
-     *  Returns true if the model contains any properties with a public setter
+     * Returns true if the model contains any properties with a public setter
-     *  If true, the model's constructor accessor should be made public to ensure end users
+     * If true, the model's constructor accessor should be made public to ensure end users
-     *  can instantiate the object. If false, then the model is only ever given
+     * can instantiate the object. If false, then the model is only ever given
-     *  to us by the server, so we do not need a public constructor
+     * to us by the server, so we do not need a public constructor
      */
     private boolean modelIsMutatable(CodegenModel model, Set<String> processed) {
         if (processed == null) {
@@ -850,14 +850,18 @@ public abstract class AbstractCSharpCodegen extends DefaultCodegen implements Co
         }
     }
 
-    /** Returns the model related to the given parameter */
+    /**
+     * Returns the model related to the given parameter
+     */
     private CodegenModel getModelFromParameter(List<ModelMap> allModels, CodegenParameter parameter) {
         return parameter.isModel
-            ? allModels.stream().map(m -> m.getModel()).filter(m -> m.getClassname().equals(parameter.dataType)).findFirst().orElse(null)
+                ? allModels.stream().map(m -> m.getModel()).filter(m -> m.getClassname().equals(parameter.dataType)).findFirst().orElse(null)
-            : null;
+                : null;
     }
 
-    /** This is the same as patchVendorExtensionNullableValueType except it uses the deprecated getNullableTypes property */
+    /**
+     * This is the same as patchVendorExtensionNullableValueType except it uses the deprecated getNullableTypes property
+     */
     protected void patchVendorExtensionNullableValueTypeLegacy(CodegenParameter parameter) {
         if (parameter.isNullable && !parameter.isContainer && (this.getNullableTypes().contains(parameter.dataType) || parameter.isEnum)) {
             parameter.vendorExtensions.put("x-nullable-value-type", true);
@@ -1021,8 +1025,8 @@ public abstract class AbstractCSharpCodegen extends DefaultCodegen implements Co
         name = this.escapeReservedWord(name);
 
         return name.equalsIgnoreCase(model.getClassname())
-            ? this.invalidNamePrefix + camelize(name)
+                ? this.invalidNamePrefix + camelize(name)
-            : name;
+                : name;
     }
 
     @Override
@@ -1046,8 +1050,8 @@ public abstract class AbstractCSharpCodegen extends DefaultCodegen implements Co
     @Override
     public String toExampleValue(Schema p) {
         return p.getExample() == null
-            ? null
+                ? null
-            : p.getExample().toString();
+                : p.getExample().toString();
     }
 
     /**
@@ -1176,6 +1180,11 @@ public abstract class AbstractCSharpCodegen extends DefaultCodegen implements Co
 
     @Override
     public String toModelName(String name) {
+        // obtain the name from modelNameMapping directly if provided
+        if (modelNameMapping.containsKey(name)) {
+            return modelNameMapping.get(name);
+        }
+
         // We need to check if schema-mapping has a different model for this class, so we use it
         // instead of the auto-generated one.
         if (schemaMapping.containsKey(name)) {

modules/openapi-generator/src/test/resources/3_0/name-parameter-mappings.yaml

@@ -42,8 +42,16 @@ paths:
       responses:
         200:
           description: OK
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/Environment'
 components:
   schemas:
+    Environment:
+      properties:
+        dummy:
+          type: string
     PropertyNameMapping:
       properties:
         http_debug_operation:

samples/client/petstore/csharp-restsharp-name-parameter-mappings/.openapi-generator/FILES

@@ -3,6 +3,7 @@ Org.OpenAPITools.sln
 README.md
 api/openapi.yaml
 appveyor.yml
+docs/Env.md
 docs/FakeApi.md
 docs/PropertyNameMapping.md
 git_push.sh
@@ -25,5 +26,6 @@ src/Org.OpenAPITools/Client/OpenAPIDateConverter.cs
 src/Org.OpenAPITools/Client/RequestOptions.cs
 src/Org.OpenAPITools/Client/RetryConfiguration.cs
 src/Org.OpenAPITools/Model/AbstractOpenAPISchema.cs
+src/Org.OpenAPITools/Model/Env.cs
 src/Org.OpenAPITools/Model/PropertyNameMapping.cs
 src/Org.OpenAPITools/Org.OpenAPITools.csproj

samples/client/petstore/csharp-restsharp-name-parameter-mappings/README.md

@@ -94,7 +94,8 @@ namespace Example
             try
             {
                 // parameter name mapping test
-                apiInstance.GetParameterNameMapping(UnderscoreType, type, TypeWithUnderscore, httpDebugOption);
+                Env result = apiInstance.GetParameterNameMapping(UnderscoreType, type, TypeWithUnderscore, httpDebugOption);
+                Debug.WriteLine(result);
             }
             catch (ApiException e)
             {
@@ -121,6 +122,7 @@ Class | Method | HTTP request | Description
 <a id="documentation-for-models"></a>
 ## Documentation for Models
 
+ - [Model.Env](docs/Env.md)
  - [Model.PropertyNameMapping](docs/PropertyNameMapping.md)
 
 

samples/client/petstore/csharp-restsharp-name-parameter-mappings/api/openapi.yaml

@@ -48,12 +48,22 @@ paths:
         style: form
       responses:
         "200":
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/Environment'
           description: OK
       summary: parameter name mapping test
       tags:
       - fake
 components:
   schemas:
+    Environment:
+      example:
+        dummy: dummy
+      properties:
+        dummy:
+          type: string
     PropertyNameMapping:
       properties:
         http_debug_operation:

samples/client/petstore/csharp-restsharp-name-parameter-mappings/docs/Env.md

@@ -0,0 +1,10 @@
+# Org.OpenAPITools.Model.Env
+
+## Properties
+
+Name | Type | Description | Notes
+------------ | ------------- | ------------- | -------------
+**Dummy** | **string** |  | [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)
+

samples/client/petstore/csharp-restsharp-name-parameter-mappings/docs/FakeApi.md

@@ -8,7 +8,7 @@ All URIs are relative to *http://localhost*
 
 <a id="getparameternamemapping"></a>
 # **GetParameterNameMapping**
-> void GetParameterNameMapping (long UnderscoreType, string type, string TypeWithUnderscore, string httpDebugOption)
+> Env GetParameterNameMapping (long UnderscoreType, string type, string TypeWithUnderscore, string httpDebugOption)
 
 parameter name mapping test
 
@@ -37,7 +37,8 @@ namespace Example
             try
             {
                 // parameter name mapping test
-                apiInstance.GetParameterNameMapping(UnderscoreType, type, TypeWithUnderscore, httpDebugOption);
+                Env result = apiInstance.GetParameterNameMapping(UnderscoreType, type, TypeWithUnderscore, httpDebugOption);
+                Debug.WriteLine(result);
             }
             catch (ApiException  e)
             {
@@ -57,7 +58,10 @@ This returns an ApiResponse object which contains the response data, status code
 try
 {
     // parameter name mapping test
-    apiInstance.GetParameterNameMappingWithHttpInfo(UnderscoreType, type, TypeWithUnderscore, httpDebugOption);
+    ApiResponse<Env> response = apiInstance.GetParameterNameMappingWithHttpInfo(UnderscoreType, type, TypeWithUnderscore, httpDebugOption);
+    Debug.Write("Status Code: " + response.StatusCode);
+    Debug.Write("Response Headers: " + response.Headers);
+    Debug.Write("Response Body: " + response.Data);
 }
 catch (ApiException e)
 {
@@ -78,7 +82,7 @@ catch (ApiException e)
 
 ### Return type
 
-void (empty response body)
+[**Env**](Env.md)
 
 ### Authorization
 
@@ -87,7 +91,7 @@ No authorization required
 ### HTTP request headers
 
  - **Content-Type**: Not defined
- - **Accept**: Not defined
+ - **Accept**: application/json
 
 
 ### HTTP response details

samples/client/petstore/csharp-restsharp-name-parameter-mappings/src/Org.OpenAPITools.Test/Model/EnvTests.cs

@@ -0,0 +1,66 @@
+/*
+ * Dummy
+ *
+ * To test name, parameter mapping options
+ *
+ * The version of the OpenAPI document: 1.0.0
+ * Generated by: https://github.com/openapitools/openapi-generator.git
+ */
+
+
+using Xunit;
+
+using System;
+using System.Linq;
+using System.IO;
+using System.Collections.Generic;
+using Org.OpenAPITools.Model;
+using Org.OpenAPITools.Client;
+using System.Reflection;
+using Newtonsoft.Json;
+
+namespace Org.OpenAPITools.Test.Model
+{
+    /// <summary>
+    ///  Class for testing Env
+    /// </summary>
+    /// <remarks>
+    /// This file is automatically generated by OpenAPI Generator (https://openapi-generator.tech).
+    /// Please update the test case below to test the model.
+    /// </remarks>
+    public class EnvTests : IDisposable
+    {
+        // TODO uncomment below to declare an instance variable for Env
+        //private Env instance;
+
+        public EnvTests()
+        {
+            // TODO uncomment below to create an instance of Env
+            //instance = new Env();
+        }
+
+        public void Dispose()
+        {
+            // Cleanup when everything is done.
+        }
+
+        /// <summary>
+        /// Test an instance of Env
+        /// </summary>
+        [Fact]
+        public void EnvInstanceTest()
+        {
+            // TODO uncomment below to test "IsType" Env
+            //Assert.IsType<Env>(instance);
+        }
+
+        /// <summary>
+        /// Test the property 'Dummy'
+        /// </summary>
+        [Fact]
+        public void DummyTest()
+        {
+            // TODO unit test for the property 'Dummy'
+        }
+    }
+}

samples/client/petstore/csharp-restsharp-name-parameter-mappings/src/Org.OpenAPITools.Test/Org.OpenAPITools.Test.csproj

@@ -3,7 +3,7 @@
   <PropertyGroup>
     <AssemblyName>Org.OpenAPITools.Test</AssemblyName>
     <RootNamespace>Org.OpenAPITools.Test</RootNamespace>
-    <TargetFramework>net7.0</TargetFramework>
+    <TargetFramework>net6.0</TargetFramework>
     <IsPackable>false</IsPackable>
     <Nullable>annotations</Nullable>
   </PropertyGroup>

samples/client/petstore/csharp-restsharp-name-parameter-mappings/src/Org.OpenAPITools/Api/FakeApi.cs

@@ -15,6 +15,7 @@ using System.Linq;
 using System.Net;
 using System.Net.Mime;
 using Org.OpenAPITools.Client;
+using Org.OpenAPITools.Model;
 
 namespace Org.OpenAPITools.Api
 {
@@ -34,8 +35,8 @@ namespace Org.OpenAPITools.Api
         /// <param name="TypeWithUnderscore">type_</param>
         /// <param name="httpDebugOption">http debug option (to test parameter naming option)</param>
         /// <param name="operationIndex">Index associated with the operation.</param>
-        /// <returns></returns>
+        /// <returns>Env</returns>
-        void GetParameterNameMapping(long UnderscoreType, string type, string TypeWithUnderscore, string httpDebugOption, int operationIndex = 0);
+        Env GetParameterNameMapping(long UnderscoreType, string type, string TypeWithUnderscore, string httpDebugOption, int operationIndex = 0);
 
         /// <summary>
         /// parameter name mapping test
@@ -49,8 +50,8 @@ namespace Org.OpenAPITools.Api
         /// <param name="TypeWithUnderscore">type_</param>
         /// <param name="httpDebugOption">http debug option (to test parameter naming option)</param>
         /// <param name="operationIndex">Index associated with the operation.</param>
-        /// <returns>ApiResponse of Object(void)</returns>
+        /// <returns>ApiResponse of Env</returns>
-        ApiResponse<Object> GetParameterNameMappingWithHttpInfo(long UnderscoreType, string type, string TypeWithUnderscore, string httpDebugOption, int operationIndex = 0);
+        ApiResponse<Env> GetParameterNameMappingWithHttpInfo(long UnderscoreType, string type, string TypeWithUnderscore, string httpDebugOption, int operationIndex = 0);
         #endregion Synchronous Operations
     }
 
@@ -73,8 +74,8 @@ namespace Org.OpenAPITools.Api
         /// <param name="httpDebugOption">http debug option (to test parameter naming option)</param>
         /// <param name="operationIndex">Index associated with the operation.</param>
         /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
-        /// <returns>Task of void</returns>
+        /// <returns>Task of Env</returns>
-        System.Threading.Tasks.Task GetParameterNameMappingAsync(long UnderscoreType, string type, string TypeWithUnderscore, string httpDebugOption, int operationIndex = 0, System.Threading.CancellationToken cancellationToken = default(System.Threading.CancellationToken));
+        System.Threading.Tasks.Task<Env> GetParameterNameMappingAsync(long UnderscoreType, string type, string TypeWithUnderscore, string httpDebugOption, int operationIndex = 0, System.Threading.CancellationToken cancellationToken = default(System.Threading.CancellationToken));
 
         /// <summary>
         /// parameter name mapping test
@@ -89,8 +90,8 @@ namespace Org.OpenAPITools.Api
         /// <param name="httpDebugOption">http debug option (to test parameter naming option)</param>
         /// <param name="operationIndex">Index associated with the operation.</param>
         /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
-        /// <returns>Task of ApiResponse</returns>
+        /// <returns>Task of ApiResponse (Env)</returns>
-        System.Threading.Tasks.Task<ApiResponse<Object>> GetParameterNameMappingWithHttpInfoAsync(long UnderscoreType, string type, string TypeWithUnderscore, string httpDebugOption, int operationIndex = 0, System.Threading.CancellationToken cancellationToken = default(System.Threading.CancellationToken));
+        System.Threading.Tasks.Task<ApiResponse<Env>> GetParameterNameMappingWithHttpInfoAsync(long UnderscoreType, string type, string TypeWithUnderscore, string httpDebugOption, int operationIndex = 0, System.Threading.CancellationToken cancellationToken = default(System.Threading.CancellationToken));
         #endregion Asynchronous Operations
     }
 
@@ -220,10 +221,11 @@ namespace Org.OpenAPITools.Api
         /// <param name="TypeWithUnderscore">type_</param>
         /// <param name="httpDebugOption">http debug option (to test parameter naming option)</param>
         /// <param name="operationIndex">Index associated with the operation.</param>
-        /// <returns></returns>
+        /// <returns>Env</returns>
-        public void GetParameterNameMapping(long UnderscoreType, string type, string TypeWithUnderscore, string httpDebugOption, int operationIndex = 0)
+        public Env GetParameterNameMapping(long UnderscoreType, string type, string TypeWithUnderscore, string httpDebugOption, int operationIndex = 0)
         {
-            GetParameterNameMappingWithHttpInfo(UnderscoreType, type, TypeWithUnderscore, httpDebugOption);
+            Org.OpenAPITools.Client.ApiResponse<Env> localVarResponse = GetParameterNameMappingWithHttpInfo(UnderscoreType, type, TypeWithUnderscore, httpDebugOption);
+            return localVarResponse.Data;
         }
 
         /// <summary>
@@ -235,8 +237,8 @@ namespace Org.OpenAPITools.Api
         /// <param name="TypeWithUnderscore">type_</param>
         /// <param name="httpDebugOption">http debug option (to test parameter naming option)</param>
         /// <param name="operationIndex">Index associated with the operation.</param>
-        /// <returns>ApiResponse of Object(void)</returns>
+        /// <returns>ApiResponse of Env</returns>
-        public Org.OpenAPITools.Client.ApiResponse<Object> GetParameterNameMappingWithHttpInfo(long UnderscoreType, string type, string TypeWithUnderscore, string httpDebugOption, int operationIndex = 0)
+        public Org.OpenAPITools.Client.ApiResponse<Env> GetParameterNameMappingWithHttpInfo(long UnderscoreType, string type, string TypeWithUnderscore, string httpDebugOption, int operationIndex = 0)
         {
             // verify the required parameter 'type' is set
             if (type == null)
@@ -263,6 +265,7 @@ namespace Org.OpenAPITools.Api
 
             // to determine the Accept header
             string[] _accepts = new string[] {
+                "application/json"
             };
 
             var localVarContentType = Org.OpenAPITools.Client.ClientUtils.SelectHeaderContentType(_contentTypes);
@@ -287,7 +290,7 @@ namespace Org.OpenAPITools.Api
 
 
             // make the HTTP request
-            var localVarResponse = this.Client.Get<Object>("/fake/parameter-name-mapping", localVarRequestOptions, this.Configuration);
+            var localVarResponse = this.Client.Get<Env>("/fake/parameter-name-mapping", localVarRequestOptions, this.Configuration);
             if (this.ExceptionFactory != null)
             {
                 Exception _exception = this.ExceptionFactory("GetParameterNameMapping", localVarResponse);
@@ -310,10 +313,11 @@ namespace Org.OpenAPITools.Api
         /// <param name="httpDebugOption">http debug option (to test parameter naming option)</param>
         /// <param name="operationIndex">Index associated with the operation.</param>
         /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
-        /// <returns>Task of void</returns>
+        /// <returns>Task of Env</returns>
-        public async System.Threading.Tasks.Task GetParameterNameMappingAsync(long UnderscoreType, string type, string TypeWithUnderscore, string httpDebugOption, int operationIndex = 0, System.Threading.CancellationToken cancellationToken = default(System.Threading.CancellationToken))
+        public async System.Threading.Tasks.Task<Env> GetParameterNameMappingAsync(long UnderscoreType, string type, string TypeWithUnderscore, string httpDebugOption, int operationIndex = 0, System.Threading.CancellationToken cancellationToken = default(System.Threading.CancellationToken))
         {
-            await GetParameterNameMappingWithHttpInfoAsync(UnderscoreType, type, TypeWithUnderscore, httpDebugOption, operationIndex, cancellationToken).ConfigureAwait(false);
+            Org.OpenAPITools.Client.ApiResponse<Env> localVarResponse = await GetParameterNameMappingWithHttpInfoAsync(UnderscoreType, type, TypeWithUnderscore, httpDebugOption, operationIndex, cancellationToken).ConfigureAwait(false);
+            return localVarResponse.Data;
         }
 
         /// <summary>
@@ -326,8 +330,8 @@ namespace Org.OpenAPITools.Api
         /// <param name="httpDebugOption">http debug option (to test parameter naming option)</param>
         /// <param name="operationIndex">Index associated with the operation.</param>
         /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
-        /// <returns>Task of ApiResponse</returns>
+        /// <returns>Task of ApiResponse (Env)</returns>
-        public async System.Threading.Tasks.Task<Org.OpenAPITools.Client.ApiResponse<Object>> GetParameterNameMappingWithHttpInfoAsync(long UnderscoreType, string type, string TypeWithUnderscore, string httpDebugOption, int operationIndex = 0, System.Threading.CancellationToken cancellationToken = default(System.Threading.CancellationToken))
+        public async System.Threading.Tasks.Task<Org.OpenAPITools.Client.ApiResponse<Env>> GetParameterNameMappingWithHttpInfoAsync(long UnderscoreType, string type, string TypeWithUnderscore, string httpDebugOption, int operationIndex = 0, System.Threading.CancellationToken cancellationToken = default(System.Threading.CancellationToken))
         {
             // verify the required parameter 'type' is set
             if (type == null)
@@ -355,6 +359,7 @@ namespace Org.OpenAPITools.Api
 
             // to determine the Accept header
             string[] _accepts = new string[] {
+                "application/json"
             };
 
             var localVarContentType = Org.OpenAPITools.Client.ClientUtils.SelectHeaderContentType(_contentTypes);
@@ -379,7 +384,7 @@ namespace Org.OpenAPITools.Api
 
 
             // make the HTTP request
-            var localVarResponse = await this.AsynchronousClient.GetAsync<Object>("/fake/parameter-name-mapping", localVarRequestOptions, this.Configuration, cancellationToken).ConfigureAwait(false);
+            var localVarResponse = await this.AsynchronousClient.GetAsync<Env>("/fake/parameter-name-mapping", localVarRequestOptions, this.Configuration, cancellationToken).ConfigureAwait(false);
 
             if (this.ExceptionFactory != null)
             {

samples/client/petstore/csharp-restsharp-name-parameter-mappings/src/Org.OpenAPITools/Model/Env.cs

@@ -0,0 +1,128 @@
+/*
+ * Dummy
+ *
+ * To test name, parameter mapping options
+ *
+ * The version of the OpenAPI document: 1.0.0
+ * Generated by: https://github.com/openapitools/openapi-generator.git
+ */
+
+
+using System;
+using System.Collections;
+using System.Collections.Generic;
+using System.Collections.ObjectModel;
+using System.Linq;
+using System.IO;
+using System.Runtime.Serialization;
+using System.Text;
+using System.Text.RegularExpressions;
+using Newtonsoft.Json;
+using Newtonsoft.Json.Converters;
+using Newtonsoft.Json.Linq;
+using System.ComponentModel.DataAnnotations;
+using OpenAPIDateConverter = Org.OpenAPITools.Client.OpenAPIDateConverter;
+
+namespace Org.OpenAPITools.Model
+{
+    /// <summary>
+    /// Env
+    /// </summary>
+    [DataContract(Name = "Environment")]
+    public partial class Env : IEquatable<Env>, IValidatableObject
+    {
+        /// <summary>
+        /// Initializes a new instance of the <see cref="Env" /> class.
+        /// </summary>
+        /// <param name="dummy">dummy.</param>
+        public Env(string dummy = default(string))
+        {
+            this.Dummy = dummy;
+        }
+
+        /// <summary>
+        /// Gets or Sets Dummy
+        /// </summary>
+        [DataMember(Name = "dummy", EmitDefaultValue = false)]
+        public string Dummy { get; set; }
+
+        /// <summary>
+        /// Returns the string presentation of the object
+        /// </summary>
+        /// <returns>String presentation of the object</returns>
+        public override string ToString()
+        {
+            StringBuilder sb = new StringBuilder();
+            sb.Append("class Env {\n");
+            sb.Append("  Dummy: ").Append(Dummy).Append("\n");
+            sb.Append("}\n");
+            return sb.ToString();
+        }
+
+        /// <summary>
+        /// Returns the JSON string presentation of the object
+        /// </summary>
+        /// <returns>JSON string presentation of the object</returns>
+        public virtual string ToJson()
+        {
+            return Newtonsoft.Json.JsonConvert.SerializeObject(this, Newtonsoft.Json.Formatting.Indented);
+        }
+
+        /// <summary>
+        /// Returns true if objects are equal
+        /// </summary>
+        /// <param name="input">Object to be compared</param>
+        /// <returns>Boolean</returns>
+        public override bool Equals(object input)
+        {
+            return this.Equals(input as Env);
+        }
+
+        /// <summary>
+        /// Returns true if Env instances are equal
+        /// </summary>
+        /// <param name="input">Instance of Env to be compared</param>
+        /// <returns>Boolean</returns>
+        public bool Equals(Env input)
+        {
+            if (input == null)
+            {
+                return false;
+            }
+            return 
+                (
+                    this.Dummy == input.Dummy ||
+                    (this.Dummy != null &&
+                    this.Dummy.Equals(input.Dummy))
+                );
+        }
+
+        /// <summary>
+        /// Gets the hash code
+        /// </summary>
+        /// <returns>Hash code</returns>
+        public override int GetHashCode()
+        {
+            unchecked // Overflow is fine, just wrap
+            {
+                int hashCode = 41;
+                if (this.Dummy != null)
+                {
+                    hashCode = (hashCode * 59) + this.Dummy.GetHashCode();
+                }
+                return hashCode;
+            }
+        }
+
+        /// <summary>
+        /// To validate all properties of the instance
+        /// </summary>
+        /// <param name="validationContext">Validation context</param>
+        /// <returns>Validation Result</returns>
+        IEnumerable<System.ComponentModel.DataAnnotations.ValidationResult> IValidatableObject.Validate(ValidationContext validationContext)
+        {
+            yield break;
+        }
+    }
+
+}

samples/client/petstore/csharp-restsharp-name-parameter-mappings/src/Org.OpenAPITools/Org.OpenAPITools.csproj

@@ -2,7 +2,7 @@
 
   <PropertyGroup>
     <GenerateAssemblyInfo>false</GenerateAssemblyInfo><!-- setting GenerateAssemblyInfo to false causes this bug https://github.com/dotnet/project-system/issues/3934 -->
-    <TargetFramework>net7.0</TargetFramework>
+    <TargetFramework>net6.0</TargetFramework>
     <AssemblyName>Org.OpenAPITools</AssemblyName>
     <PackageId>Org.OpenAPITools</PackageId>
     <OutputType>Library</OutputType>

samples/client/petstore/kotlin-name-parameter-mappings/.openapi-generator/FILES

@@ -1,5 +1,6 @@
 README.md
 build.gradle
+docs/Environment.md
 docs/FakeApi.md
 docs/PropertyNameMapping.md
 gradle/wrapper/gradle-wrapper.jar
@@ -25,4 +26,5 @@ src/main/kotlin/org/openapitools/client/infrastructure/ResponseExtensions.kt
 src/main/kotlin/org/openapitools/client/infrastructure/Serializer.kt
 src/main/kotlin/org/openapitools/client/infrastructure/URIAdapter.kt
 src/main/kotlin/org/openapitools/client/infrastructure/UUIDAdapter.kt
+src/main/kotlin/org/openapitools/client/models/Environment.kt
 src/main/kotlin/org/openapitools/client/models/PropertyNameMapping.kt

samples/client/petstore/kotlin-name-parameter-mappings/README.md

@@ -50,6 +50,7 @@ Class | Method | HTTP request | Description
 <a id="documentation-for-models"></a>
 ## Documentation for Models
 
+ - [org.openapitools.client.models.Environment](docs/Environment.md)
  - [org.openapitools.client.models.PropertyNameMapping](docs/PropertyNameMapping.md)
 
 

samples/client/petstore/kotlin-name-parameter-mappings/docs/Environment.md

@@ -0,0 +1,10 @@
+
+# Environment
+
+## Properties
+Name | Type | Description | Notes
+------------ | ------------- | ------------- | -------------
+**dummy** | **kotlin.String** |  |  [optional]
+
+
+

samples/client/petstore/kotlin-name-parameter-mappings/docs/FakeApi.md

@@ -9,7 +9,7 @@ Method | HTTP request | Description
 
 <a id="getParameterNameMapping"></a>
 # **getParameterNameMapping**
-> getParameterNameMapping(underscoreType, type, typeWithUnderscore, httpDebugOption)
+> Environment getParameterNameMapping(underscoreType, type, typeWithUnderscore, httpDebugOption)
 
 parameter name mapping test
 
@@ -25,7 +25,8 @@ val type : kotlin.String = type_example // kotlin.String | type
 val typeWithUnderscore : kotlin.String = typeWithUnderscore_example // kotlin.String | type_
 val httpDebugOption : kotlin.String = httpDebugOption_example // kotlin.String | http debug option (to test parameter naming option)
 try {
-    apiInstance.getParameterNameMapping(underscoreType, type, typeWithUnderscore, httpDebugOption)
+    val result : Environment = apiInstance.getParameterNameMapping(underscoreType, type, typeWithUnderscore, httpDebugOption)
+    println(result)
 } catch (e: ClientException) {
     println("4xx response calling FakeApi#getParameterNameMapping")
     e.printStackTrace()
@@ -46,7 +47,7 @@ Name | Type | Description  | Notes
 
 ### Return type
 
-null (empty response body)
+[**Environment**](Environment.md)
 
 ### Authorization
 
@@ -55,5 +56,5 @@ No authorization required
 ### HTTP request headers
 
  - **Content-Type**: Not defined
- - **Accept**: Not defined
+ - **Accept**: application/json
 

samples/client/petstore/kotlin-name-parameter-mappings/src/main/kotlin/org/openapitools/client/apis/FakeApi.kt

@@ -19,6 +19,7 @@ import java.io.IOException
 import okhttp3.OkHttpClient
 import okhttp3.HttpUrl
 
+import org.openapitools.client.models.Environment
 
 import com.squareup.moshi.Json
 
@@ -51,19 +52,20 @@ class FakeApi(basePath: kotlin.String = defaultBasePath, client: OkHttpClient =
      * @param type type
      * @param typeWithUnderscore type_
      * @param httpDebugOption http debug option (to test parameter naming option)
-     * @return void
+     * @return Environment
      * @throws IllegalStateException If the request is not correctly configured
      * @throws IOException Rethrows the OkHttp execute method exception
      * @throws UnsupportedOperationException If the API returns an informational or redirection response
      * @throws ClientException If the API returns a client error response
      * @throws ServerException If the API returns a server error response
      */
+    @Suppress("UNCHECKED_CAST")
     @Throws(IllegalStateException::class, IOException::class, UnsupportedOperationException::class, ClientException::class, ServerException::class)
-    fun getParameterNameMapping(underscoreType: kotlin.Long, type: kotlin.String, typeWithUnderscore: kotlin.String, httpDebugOption: kotlin.String) : Unit {
+    fun getParameterNameMapping(underscoreType: kotlin.Long, type: kotlin.String, typeWithUnderscore: kotlin.String, httpDebugOption: kotlin.String) : Environment {
         val localVarResponse = getParameterNameMappingWithHttpInfo(underscoreType = underscoreType, type = type, typeWithUnderscore = typeWithUnderscore, httpDebugOption = httpDebugOption)
 
         return when (localVarResponse.responseType) {
-            ResponseType.Success -> Unit
+            ResponseType.Success -> (localVarResponse as Success<*>).data as Environment
             ResponseType.Informational -> throw UnsupportedOperationException("Client does not support Informational responses.")
             ResponseType.Redirection -> throw UnsupportedOperationException("Client does not support Redirection responses.")
             ResponseType.ClientError -> {
@@ -84,15 +86,16 @@ class FakeApi(basePath: kotlin.String = defaultBasePath, client: OkHttpClient =
      * @param type type
      * @param typeWithUnderscore type_
      * @param httpDebugOption http debug option (to test parameter naming option)
-     * @return ApiResponse<Unit?>
+     * @return ApiResponse<Environment?>
      * @throws IllegalStateException If the request is not correctly configured
      * @throws IOException Rethrows the OkHttp execute method exception
      */
+    @Suppress("UNCHECKED_CAST")
     @Throws(IllegalStateException::class, IOException::class)
-    fun getParameterNameMappingWithHttpInfo(underscoreType: kotlin.Long, type: kotlin.String, typeWithUnderscore: kotlin.String, httpDebugOption: kotlin.String) : ApiResponse<Unit?> {
+    fun getParameterNameMappingWithHttpInfo(underscoreType: kotlin.Long, type: kotlin.String, typeWithUnderscore: kotlin.String, httpDebugOption: kotlin.String) : ApiResponse<Environment?> {
         val localVariableConfig = getParameterNameMappingRequestConfig(underscoreType = underscoreType, type = type, typeWithUnderscore = typeWithUnderscore, httpDebugOption = httpDebugOption)
 
-        return request<Unit, Unit>(
+        return request<Unit, Environment>(
             localVariableConfig
         )
     }
@@ -116,7 +119,8 @@ class FakeApi(basePath: kotlin.String = defaultBasePath, client: OkHttpClient =
         val localVariableHeaders: MutableMap<String, String> = mutableMapOf()
         underscoreType.apply { localVariableHeaders["_type"] = this.toString() }
         typeWithUnderscore.apply { localVariableHeaders["type_"] = this.toString() }
-        
+        localVariableHeaders["Accept"] = "application/json"
+
         return RequestConfig(
             method = RequestMethod.GET,
             path = "/fake/parameter-name-mapping",

samples/client/petstore/kotlin-name-parameter-mappings/src/main/kotlin/org/openapitools/client/models/Environment.kt

@@ -0,0 +1,35 @@
+/**
+ *
+ * Please note:
+ * This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * Do not edit this file manually.
+ *
+ */
+
+@file:Suppress(
+    "ArrayInDataClass",
+    "EnumEntryName",
+    "RemoveRedundantQualifierName",
+    "UnusedImport"
+)
+
+package org.openapitools.client.models
+
+
+import com.squareup.moshi.Json
+import com.squareup.moshi.JsonClass
+
+/**
+ * 
+ *
+ * @param dummy 
+ */
+
+
+data class Environment (
+
+    @Json(name = "dummy")
+    val dummy: kotlin.String? = null
+
+)
+