Feat: Add freezed serialization to dart-dio generator

.github/workflows/samples-dart-freezed.yaml

@@ -0,0 +1,39 @@
+name: Samples Dart
+
+on:
+  push:
+    branches:
+      - master
+      - '[5-9]+.[0-9]+.x'
+  pull_request:
+    branches:
+      - master
+      - '[5-9]+.[0-9]+.x'
+    paths:
+      - 'samples/openapi3/client/petstore/dart*/freezed'
+
+jobs:
+  tests-dart:
+    name: Tests Dart
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-java@v4
+        with:
+          distribution: 'temurin'
+          java-version: 11
+          cache: maven
+      - name: Cache test dependencies
+        uses: actions/cache@v4
+        env:
+          cache-name: pub-cache
+        with:
+          path: $PUB_CACHE
+          key: ${{ runner.os }}-${{ github.job }}-${{ env.cache-name }}-${{ hashFiles('samples/**/pubspec.*') }}
+      - uses: dart-lang/setup-dart@v1
+        with:
+          sdk: 3.0.0
+      - name: Run tests
+        uses: ./.github/actions/run-samples
+        with:
+          name: samples.dart

.github/workflows/samples-dart.yaml

@@ -11,6 +11,8 @@ on:
       - '[5-9]+.[0-9]+.x'
     paths:
       - 'samples/openapi3/client/petstore/dart*/**'
+      - '!samples/openapi3/client/petstore/dart*/freezed'
+
 
 jobs:
   tests-dart:

bin/configs/dart-dio-oneof-freezed.yaml

@@ -0,0 +1,12 @@
+generatorName: dart-dio
+outputDir: samples/openapi3/client/petstore/dart-dio/freezed/oneof
+inputSpec: modules/openapi-generator/src/test/resources/3_0/oneOf.yaml
+templateDir: modules/openapi-generator/src/main/resources/dart/libraries/dio
+typeMappings:
+  Client: "ModelClient"
+  File: "ModelFile"
+  EnumClass: "ModelEnumClass"
+additionalProperties:
+  hideGenerationTimestamp: "true"
+  serializationLibrary: "freezed"
+

bin/configs/dart-dio-oneof-polymorphism-and-inheritance-freezed.yaml

@@ -0,0 +1,12 @@
+generatorName: dart-dio
+outputDir: samples/openapi3/client/petstore/dart-dio/freezed/oneof_polymorphism_and_inheritance
+inputSpec: modules/openapi-generator/src/test/resources/3_0/oneof_polymorphism_and_inheritance.yaml
+templateDir: modules/openapi-generator/src/main/resources/dart/libraries/dio
+typeMappings:
+  Client: "ModelClient"
+  File: "ModelFile"
+  EnumClass: "ModelEnumClass"
+additionalProperties:
+  hideGenerationTimestamp: "true"
+  enumUnknownDefaultCase: "true"
+  serializationLibrary: "freezed"

bin/configs/dart-dio-oneof-primitive-freezed.yaml

@@ -0,0 +1,12 @@
+generatorName: dart-dio
+outputDir: samples/openapi3/client/petstore/dart-dio/freezed/oneof_primitive
+inputSpec: modules/openapi-generator/src/test/resources/3_0/oneOf_primitive.yaml
+templateDir: modules/openapi-generator/src/main/resources/dart/libraries/dio
+typeMappings:
+  Client: "ModelClient"
+  File: "ModelFile"
+  EnumClass: "ModelEnumClass"
+additionalProperties:
+  hideGenerationTimestamp: "true"
+  enumUnknownDefaultCase: "true"
+  serializationLibrary: "freezed"

bin/configs/dart-dio-petstore-client-lib-fake-freezed.yaml

@@ -0,0 +1,12 @@
+generatorName: dart-dio
+outputDir: samples/openapi3/client/petstore/dart-dio/freezed/petstore_client_lib_fake
+inputSpec: modules/openapi-generator/src/test/resources/3_0/petstore-with-fake-endpoints-models-for-testing.yaml
+templateDir: modules/openapi-generator/src/main/resources/dart/libraries/dio
+typeMappings:
+  Client: "ModelClient"
+  File: "ModelFile"
+  EnumClass: "ModelEnumClass"
+additionalProperties:
+  hideGenerationTimestamp: "true"
+  enumUnknownDefaultCase: "true"
+  serializationLibrary: "freezed"

docs/generators/dart-dio.md

@@ -36,7 +36,7 @@ These options may be applied as additional-properties (cli) or configOptions (pl
 |pubPublishTo|Publish_to in generated pubspec| |null|
 |pubRepository|Repository in generated pubspec| |null|
 |pubVersion|Version in generated pubspec| |1.0.0|
-|serializationLibrary|Specify serialization library|<dl><dt>**built_value**</dt><dd>[DEFAULT] built_value</dd><dt>**json_serializable**</dt><dd>[BETA] json_serializable</dd></dl>|built_value|
+|serializationLibrary|Specify serialization library|<dl><dt>**built_value**</dt><dd>[DEFAULT] built_value</dd><dt>**json_serializable**</dt><dd>[BETA] json_serializable</dd><dt>**freezed**</dt><dd>[BETA] freezed</dd></dl>|built_value|
 |skipCopyWith|Skip CopyWith when using Json Serializable for serialization| |false|
 |sortModelPropertiesByRequiredFlag|Sort model properties to place required parameters before optional parameters.| |true|
 |sortParamsByRequiredFlag|Sort method arguments to place required parameters before optional parameters.| |true|

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

@@ -24,6 +24,7 @@
 import lombok.Getter;
 import lombok.Setter;
 import org.apache.commons.lang3.ObjectUtils;
+import org.apache.commons.lang3.StringUtils;
 import org.openapitools.codegen.*;
 import org.openapitools.codegen.CodegenDiscriminator.MappedModel;
 import org.openapitools.codegen.api.TemplatePathLocator;
@@ -49,6 +50,8 @@
 import java.util.*;
 import java.util.stream.Collectors;
 
+import static org.openapitools.codegen.utils.CamelizeOption.LOWERCASE_FIRST_LETTER;
+import static org.openapitools.codegen.utils.StringUtils.camelize;
 import static org.openapitools.codegen.utils.StringUtils.underscore;
 
 public class DartDioClientCodegen extends AbstractDartCodegen {
@@ -65,6 +68,8 @@ public class DartDioClientCodegen extends AbstractDartCodegen {
     public static final String EQUALITY_CHECK_METHOD_EQUATABLE = "equatable";
     public static final String SERIALIZATION_LIBRARY_BUILT_VALUE = "built_value";
     public static final String SERIALIZATION_LIBRARY_JSON_SERIALIZABLE = "json_serializable";
+
+    public static final String SERIALIZATION_LIBRARY_FREEZED = "freezed";
     public static final String SERIALIZATION_LIBRARY_DEFAULT = SERIALIZATION_LIBRARY_BUILT_VALUE;
 
     private static final String DIO_IMPORT = "package:dio/dio.dart";
@@ -74,6 +79,7 @@ public class DartDioClientCodegen extends AbstractDartCodegen {
     public static final String SKIP_COPY_WITH_DEFAULT_VALUE = "false";
 
     private static final String CLIENT_NAME = "clientName";
+    private static final String FREEZED_UNION_RESPONSE = "freezedUnionResponse";
 
     @Getter @Setter
     private String dateLibrary;
@@ -111,6 +117,7 @@ public DartDioClientCodegen() {
 
         supportedLibraries.put(SERIALIZATION_LIBRARY_BUILT_VALUE, "[DEFAULT] built_value");
         supportedLibraries.put(SERIALIZATION_LIBRARY_JSON_SERIALIZABLE, "[BETA] json_serializable");
+        supportedLibraries.put(SERIALIZATION_LIBRARY_FREEZED, "[BETA] freezed");
         final CliOption serializationLibrary = CliOption.newString(CodegenConstants.SERIALIZATION_LIBRARY, "Specify serialization library");
         serializationLibrary.setEnum(supportedLibraries);
         serializationLibrary.setDefault(SERIALIZATION_LIBRARY_DEFAULT);
@@ -231,6 +238,10 @@ private void configureSerializationLibrary(String srcFolder) {
                 additionalProperties.put("useJsonSerializable", "true");
                 configureSerializationLibraryJsonSerializable(srcFolder);
                 break;
+            case SERIALIZATION_LIBRARY_FREEZED:
+                additionalProperties.put("useFreezed", "true");
+                configureSerializationLibraryFreezed(srcFolder);
+                break;
             default:
             case SERIALIZATION_LIBRARY_BUILT_VALUE:
                 additionalProperties.put("useBuiltValue", "true");
@@ -306,6 +317,94 @@ private void configureEqualityCheckMethod(String srcFolder) {
         }
     }
 
+    private void configureSerializationLibraryFreezed(String srcFolder) {
+        if (!additionalProperties.containsKey(FREEZED_UNION_RESPONSE)) {
+            additionalProperties.put(FREEZED_UNION_RESPONSE, false);
+            LOGGER.debug("freezedUnionResponse not set, using default {}", false);
+        }
+        supportingFiles.add(new SupportingFile("serialization/freezed/build.yaml.mustache", "" /* main project dir */, "build.yaml"));
+        supportingFiles.add(new SupportingFile("serialization/freezed/models.dart.mustache", srcFolder + File.separator + modelPackage, "models.dart"));
+        supportingFiles.add(new SupportingFile("serialization/freezed/primitive_union_types.mustache", srcFolder + File.separator + modelPackage, "primitive_union_types.dart"));
+        if(((boolean) additionalProperties.getOrDefault(FREEZED_UNION_RESPONSE, false))){
+            supportingFiles.add(new SupportingFile("serialization/freezed/response_models.mustache", srcFolder + File.separator + modelPackage, "response_models.dart"));
+        }
+        // most of these are defined in AbstractDartCodegen, we are overriding
+        // just the binary / file handling
+        languageSpecificPrimitives.add("Object");
+        imports.put("Uint8List", "dart:typed_data");
+        imports.put("MultipartFile", DIO_IMPORT);
+        // A lambda which removes the model name prefix and suffix. Used mainly for default descrimator class name
+        // mapping in fromJson methods for unions in freezed.
+        additionalProperties.put("DelModelNamePrefixSuffix", (Mustache.Lambda) (fragment, writer) -> {
+            String content = fragment.execute();
+            content = content.trim().replaceAll("\n", "");
+            content = content.replaceAll(this.modelNamePrefix, "");
+            content = content.replaceAll(this.modelNameSuffix, "");
+            writer.write(content);
+        });
+        // A lambda which transforms Types for naming factory constructors inFreezed unions.
+        additionalProperties.put("PrimitiveInUnion", (Mustache.Lambda) (fragment, writer) -> {
+            String content = fragment.execute();
+            content = content.trim().replaceAll("\n", "");
+            Set<String> collectionTypes = Sets.newHashSet("List","Map","Set");
+            Set<String> nonCollectionTypes = defaultIncludes.stream().filter(e -> !collectionTypes.contains(e)).collect(Collectors.toSet());
+            if(nonCollectionTypes.contains(content)){
+                writer.write(content + "InUnion");
+                return;
+            }
+            writer.write(content);
+        });
+        // A lambda to generate correct form of FromJson methods.
+        additionalProperties.put("PrimitiveFromJson", (Mustache.Lambda) (fragment, writer) -> {
+            String content = fragment.execute();
+            content = content.trim().replaceAll("\n", "");
+            // Remove Generics Declarations as this is not required for factoryNames in freezed
+            String tmp_1 = StringUtils.substringBefore(content, "<");
+            if(defaultIncludes.contains(tmp_1)) {
+                if (tmp_1.equals("Set") || tmp_1.equals("Map")) {
+                    content = "<"+StringUtils.substringAfter(content, "<")+"{}";
+                }else if(tmp_1.equals("List")){
+                    content = "<"+StringUtils.substringAfter(content, "<")+"[]";
+                }else{
+                    content = tmp_1+"InUnion";
+                }
+            }
+            writer.write(content);
+        });
+        // A lambda to filter out collection types from anyOf and oneOf sets in codegenmodel.
+        additionalProperties.put("PrimitiveCollectionsExtension", (Mustache.Lambda) (fragment, writer) -> {
+            String content = fragment.execute();
+            content = content.trim().replaceAll("\n", "");
+            Set<String> collectionTypes = Sets.newHashSet("List","Map","Set");
+            // Remove Generics Declarations as this is not required for factoryNames in freezed
+            String tmp_1 = StringUtils.substringBefore(content, "<");
+            if(collectionTypes.contains(tmp_1)){
+                String variableName = camelize(fragment.execute().replace(" ", "_"), LOWERCASE_FIRST_LETTER);
+                variableName = this.sanitizeName(variableName);
+                if (this.reservedWords().contains(variableName)) {
+                    // Escaping must be done *after* camelize, because generators may escape using characters removed by camelize function.
+                    variableName = this.escapeReservedWord(variableName);
+                }
+                tmp_1 = String.join("\n", "extension on "+ content + "{",
+                    "dynamic fromJson(Map<String,dynamic> json) {",
+                        "return json[\""+variableName+"Value\"];",
+                    "}",
+
+                    "Map<String,dynamic> toJson() {",
+                        "return <String, dynamic>{",
+                                "\""+variableName+"Value\": this,",
+                            "};",
+                    "}",
+                "}");
+                writer.write(tmp_1);
+            }else{
+                writer.write("");
+
+            }
+        });
+
+    }
+
     private void configureDateLibrary(String srcFolder) {
         switch (dateLibrary) {
             case DATE_LIBRARY_TIME_MACHINE:
@@ -602,7 +701,7 @@ protected CodegenDiscriminator createDiscriminator(String schemaName, Schema sch
     @Override
     public Map<String, ModelsMap> postProcessAllModels(Map<String, ModelsMap> objs) {
         objs = super.postProcessAllModels(objs);
-        if (SERIALIZATION_LIBRARY_BUILT_VALUE.equals(library)) {
+        if (SERIALIZATION_LIBRARY_BUILT_VALUE.equals(library) || SERIALIZATION_LIBRARY_FREEZED.equals(library)) {
             adaptToDartInheritance(objs);
             syncRootTypesWithInnerVars(objs);
         }

modules/openapi-generator/src/main/resources/dart/libraries/dio/analysis_options.mustache

@@ -6,5 +6,9 @@ analyzer:
   exclude:
     - test/*.dart{{#useJsonSerializable}}
     - lib/{{sourceFolder}}/model/*.g.dart{{/useJsonSerializable}}
+    {{#useFreezed}}
+    - lib/src/model/*.g.dart
+    - lib/src/model/*.freezed.dart
+    {{/useFreezed}}
   errors:
     deprecated_member_use_from_same_package: ignore

modules/openapi-generator/src/main/resources/dart/libraries/dio/api.mustache

@@ -5,8 +5,12 @@ import 'dart:async';
 import 'package:dio/dio.dart';
 
 {{#operations}}
-{{#imports}}import '{{.}}';
-{{/imports}}
+{{! No need to Import all the required model files as freezed uses the part of directive for it models}}
+{{^useFreezed}}
+    {{#imports}}
+import '{{.}}';
+    {{/imports}}
+{{/useFreezed}}
 
 class {{classname}} {
 
@@ -38,7 +42,16 @@ class {{classname}} {
   {{#isDeprecated}}
   @Deprecated('This operation has been deprecated')
   {{/isDeprecated}}
-  Future<Response<{{{returnType}}}{{^returnType}}void{{/returnType}}>> {{nickname}}({ {{#allParams}}{{#isPathParam}}
+  {{#useFreezed}}
+      {{#freezedUnionResponse}}
+          Future<Response<{{#lambda.titlecase}}{{nickname}}{{/lambda.titlecase}}Data>> {{nickname}}({
+      {{/freezedUnionResponse}}
+      {{^freezedUnionResponse}}
+              Future<Response<{{{returnType}}}{{^returnType}}void{{/returnType}}>> {{nickname}}({
+      {{/freezedUnionResponse}}
+  {{/useFreezed}}
+  {{^useFreezed}}
+  Future<Response<{{{returnType}}}{{^returnType}}void{{/returnType}}>> {{nickname}}({ {{/useFreezed}}{{#allParams}}{{#isPathParam}}
     {{#isDeprecated}}@Deprecated('{{paramName}} is deprecated') {{/isDeprecated}}required {{{dataType}}} {{paramName}},{{/isPathParam}}{{#isQueryParam}}
     {{#isDeprecated}}@Deprecated('{{paramName}} is deprecated') {{/isDeprecated}}{{#required}}{{^isNullable}}{{^defaultValue}}required {{/defaultValue}}{{/isNullable}}{{/required}}{{{dataType}}}{{#required}}{{#isNullable}}?{{/isNullable}}{{/required}}{{^required}}?{{/required}} {{paramName}}{{^isContainer}}{{#defaultValue}} = {{{.}}}{{/defaultValue}}{{/isContainer}},{{/isQueryParam}}{{#isHeaderParam}}
     {{#isDeprecated}}@Deprecated('{{paramName}} is deprecated') {{/isDeprecated}}{{#required}}{{^isNullable}}{{^defaultValue}}required {{/defaultValue}}{{/isNullable}}{{/required}}{{{dataType}}}{{#required}}{{#isNullable}}?{{/isNullable}}{{/required}}{{^required}}?{{/required}} {{paramName}}{{^isContainer}}{{#defaultValue}} = {{{.}}}{{/defaultValue}}{{/isContainer}},{{/isHeaderParam}}{{#isBodyParam}}
@@ -116,7 +129,15 @@ class {{classname}} {
     );
     {{#returnType}}
 
-    {{{.}}}? _responseData;
+    {{#useFreezed}}
+        {{#freezedUnionResponse}}
+            {{#lambda.titlecase}}{{nickname}}{{/lambda.titlecase}}Data _responseData;
+        {{/freezedUnionResponse}}
+        {{^freezedUnionResponse}}
+            {{{returnType}}} _responseData;
+        {{/freezedUnionResponse}}
+    {{/useFreezed}}
+    {{^useFreezed}}{{{.}}}? _responseData;{{/useFreezed}}
 
     try {
 {{#includeLibraryTemplate}}api/deserialize{{/includeLibraryTemplate}}
@@ -130,7 +151,17 @@ class {{classname}} {
       );
     }
 
+    {{#useFreezed}}
+        {{#freezedUnionResponse}}
+    return Response<{{#lambda.titlecase}}{{nickname}}{{/lambda.titlecase}}Data>(
+        {{/freezedUnionResponse}}
+        {{^freezedUnionResponse}}
     return Response<{{{returnType}}}>(
+        {{/freezedUnionResponse}}
+    {{/useFreezed}}
+    {{^useFreezed}}
+    return Response<{{{returnType}}}>(
+    {{/useFreezed}}
       data: _responseData,
       headers: _response.headers,
       isRedirect: _response.isRedirect,
@@ -139,8 +170,41 @@ class {{classname}} {
       statusCode: _response.statusCode,
       statusMessage: _response.statusMessage,
       extra: _response.extra,
-    );{{/returnType}}{{^returnType}}
-    return _response;{{/returnType}}
+    );{{/returnType}}
+    {{^returnType}}
+        {{^useFreezed}}
+    return _response;
+        {{/useFreezed}}
+        {{#useFreezed}}
+            {{#freezedUnionResponse}}
+                {{#lambda.titlecase}}{{nickname}}{{/lambda.titlecase}}Data _responseData;
+                    try {
+                        {{#includeLibraryTemplate}}api/deserialize{{/includeLibraryTemplate}}
+                    } catch (error, stackTrace) {
+                    throw DioException(
+                    requestOptions: _response.requestOptions,
+                    response: _response,
+                    type: DioExceptionType.unknown,
+                    error: error,
+                    stackTrace: stackTrace,
+                    );
+                    }
+                return Response<{{#lambda.titlecase}}{{nickname}}{{/lambda.titlecase}}Data>(
+                    data: _responseData,
+                    headers: _response.headers,
+                    isRedirect: _response.isRedirect,
+                    requestOptions: _response.requestOptions,
+                    redirects: _response.redirects,
+                    statusCode: _response.statusCode,
+                    statusMessage: _response.statusMessage,
+                    extra: _response.extra,
+                    );
+            {{/freezedUnionResponse}}
+            {{^freezedUnionResponse}}
+                    return _response;
+            {{/freezedUnionResponse}}
+        {{/useFreezed}}
+    {{/returnType}}
   }
 
   {{/operation}}

modules/openapi-generator/src/main/resources/dart/libraries/dio/lib.mustache

@@ -9,5 +9,6 @@ export 'package:{{pubName}}/{{sourceFolder}}/auth/oauth.dart';
 
 {{#apiInfo}}{{#apis}}export 'package:{{pubName}}/{{sourceFolder}}/{{apiPackage}}/{{classFilename}}.dart';
 {{/apis}}{{/apiInfo}}
-{{#models}}{{#model}}export 'package:{{pubName}}/{{sourceFolder}}/{{modelPackage}}/{{classFilename}}.dart';
-{{/model}}{{/models}}
+{{^useFreezed}}{{#models}}{{#model}}export 'package:{{pubName}}/{{sourceFolder}}/{{modelPackage}}/{{classFilename}}.dart';
+{{/model}}{{/models}}{{/useFreezed}}
+{{#useFreezed}}export 'package:{{pubName}}/{{sourceFolder}}/{{modelPackage}}/models.dart';{{/useFreezed}}