[dart][dart-dio] Add support for query collection parameter format

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

@@ -153,7 +153,6 @@ public void processOpts() {
 
         final String srcFolder = libFolder + File.separator + "src";
         supportingFiles.add(new SupportingFile("api_client.mustache", srcFolder, "api.dart"));
-        supportingFiles.add(new SupportingFile("api_util.mustache", srcFolder, "api_util.dart"));
 
         final String authFolder = srcFolder + File.separator + "auth";
         supportingFiles.add(new SupportingFile("auth/api_key_auth.mustache", authFolder, "api_key_auth.dart"));
@@ -177,6 +176,7 @@ private void configureSerializationLibrary(String srcFolder) {
 
     private void configureSerializationLibraryBuiltValue(String srcFolder) {
         supportingFiles.add(new SupportingFile("serialization/built_value/serializers.mustache", srcFolder, "serializers.dart"));
+        supportingFiles.add(new SupportingFile("serialization/built_value/api_util.mustache", srcFolder, "api_util.dart"));
 
         typeMapping.put("Array", "BuiltList");
         typeMapping.put("array", "BuiltList");
@@ -339,7 +339,7 @@ public Map<String, Object> postProcessOperationsWithModels(Map<String, Object> o
             }
 
             resultImports.addAll(rewriteImports(op.imports, false));
-            if (op.getHasFormParams()) {
+            if (op.getHasFormParams() || op.getHasQueryParams()) {
                 resultImports.add("package:" + pubName + "/src/api_util.dart");
             }
 

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

@@ -83,14 +83,13 @@ class {{classname}} {
       },{{#hasConsumes}}
       contentType: '{{#prioritizedContentTypes}}{{#-first}}{{{mediaType}}}{{/-first}}{{/prioritizedContentTypes}}',{{/hasConsumes}}
       validateStatus: validateStatus,
-    );
+    );{{#hasQueryParams}}
 
     final _queryParameters = <String, dynamic>{
       {{#queryParams}}
-      {{^required}}{{^isNullable}}if ({{{paramName}}} != null) {{/isNullable}}{{/required}}r'{{baseName}}': {{paramName}},
+      {{^required}}{{^isNullable}}if ({{{paramName}}} != null) {{/isNullable}}{{/required}}r'{{baseName}}': {{#useBuiltValue}}{{>serialization/built_value/query_param}}{{/useBuiltValue}},
       {{/queryParams}}
-    };
-    {{#hasBodyOrFormParams}}
+    };{{/hasQueryParams}}{{#hasBodyOrFormParams}}
 
     dynamic _bodyData;
 
@@ -100,20 +99,19 @@ class {{classname}} {
       throw DioError(
          requestOptions: _options.compose(
           _dio.options,
-          _path,
-          queryParameters: _queryParameters,
+          _path,{{#hasQueryParams}}
+          queryParameters: _queryParameters,{{/hasQueryParams}}
         ),
         type: DioErrorType.other,
         error: error,
       )..stackTrace = stackTrace;
-    }
-    {{/hasBodyOrFormParams}}
+    }{{/hasBodyOrFormParams}}
 
     final _response = await _dio.request<Object>(
       _path,{{#hasBodyOrFormParams}}
       data: _bodyData,{{/hasBodyOrFormParams}}
-      options: _options,
-      queryParameters: _queryParameters,
+      options: _options,{{#hasQueryParams}}
+      queryParameters: _queryParameters,{{/hasQueryParams}}
       cancelToken: cancelToken,
       onSendProgress: onSendProgress,
       onReceiveProgress: onReceiveProgress,

modules/openapi-generator/src/main/resources/dart/libraries/dio/serialization/built_value/api_util.mustache

@@ -0,0 +1,75 @@
+{{>header}}
+import 'dart:convert';
+import 'dart:typed_data';
+
+import 'package:built_collection/built_collection.dart';
+import 'package:built_value/serializer.dart';
+import 'package:dio/dio.dart';
+import 'package:dio/src/parameter.dart';
+
+/// Format the given form parameter object into something that Dio can handle.
+/// Returns primitive or String.
+/// Returns List/Map if the value is BuildList/BuiltMap.
+dynamic encodeFormParameter(Serializers serializers, dynamic value, FullType type) {
+  if (value == null) {
+    return '';
+  }
+  if (value is String || value is num || value is bool) {
+    return value;
+  }
+  final serialized = serializers.serialize(
+    value as Object,
+    specifiedType: type,
+  );
+  if (serialized is String) {
+    return serialized;
+  }
+  if (value is BuiltList || value is BuiltSet || value is BuiltMap) {
+    return serialized;
+  }
+  return json.encode(serialized);
+}
+
+dynamic encodeQueryParameter(
+  Serializers serializers,
+  dynamic value,
+  FullType type,
+) {
+  if (value == null) {
+    return '';
+  }
+  if (value is String || value is num || value is bool) {
+    return value;
+  }
+  if (value is Uint8List) {
+    // Currently not sure how to serialize this
+    return value;
+  }
+  final serialized = serializers.serialize(
+    value as Object,
+    specifiedType: type,
+  );
+  if (serialized == null) {
+    return '';
+  }
+  if (serialized is String) {
+    return serialized;
+  }
+  return serialized;
+}
+
+ListParam<T> encodeCollectionQueryParameter<T>(
+  Serializers serializers,
+  dynamic value,
+  FullType type, {
+  ListFormat format = ListFormat.multi,
+}) {
+  final serialized = serializers.serialize(
+    value as Object,
+    specifiedType: type,
+  );
+  if (value is BuiltList<T> || value is BuiltSet<T>) {
+    return ListParam(List.of((serialized as Iterable<Object?>).cast()), format);
+  }
+  throw ArgumentError('Invalid value passed to encodeCollectionQueryParameter');
+}

modules/openapi-generator/src/main/resources/dart/libraries/dio/serialization/built_value/query_param.mustache

@@ -0,0 +1 @@
+{{#isContainer}}encodeCollectionQueryParameter<{{{baseType}}}>{{/isContainer}}{{^isContainer}}encodeQueryParameter{{/isContainer}}(_serializers, {{{paramName}}}, const FullType({{^isContainer}}{{{dataType}}}){{/isContainer}}{{#isContainer}}Built{{#isMap}}Map{{/isMap}}{{#isArray}}{{#uniqueItems}}Set{{/uniqueItems}}{{^uniqueItems}}List{{/uniqueItems}}{{/isArray}}, [{{#isMap}}FullType(String), {{/isMap}}FullType({{{baseType}}})]), format: ListFormat.{{collectionFormat}}{{/isContainer}})

modules/openapi-generator/src/main/resources/dart/libraries/dio/serialization/built_value/serialize.mustache

@@ -1,9 +1,18 @@
       {{#hasFormParams}}
-      _bodyData = {{#isMultipart}}FormData.fromMap({{/isMultipart}}<String, dynamic>{
+      {{#isMultipart}}
+      _bodyData = FormData.fromMap(<String, dynamic>{
         {{#formParams}}
         {{^required}}{{^isNullable}}if ({{{paramName}}} != null) {{/isNullable}}{{/required}}r'{{{baseName}}}': {{#isFile}}{{{paramName}}}{{/isFile}}{{^isFile}}encodeFormParameter(_serializers, {{{paramName}}}, const FullType({{^isContainer}}{{{baseType}}}{{/isContainer}}{{#isContainer}}Built{{#isMap}}Map{{/isMap}}{{#isArray}}{{#uniqueItems}}Set{{/uniqueItems}}{{^uniqueItems}}List{{/uniqueItems}}{{/isArray}}, [{{#isMap}}FullType(String), {{/isMap}}FullType({{{baseType}}})]{{/isContainer}})){{/isFile}},
         {{/formParams}}
-      }{{#isMultipart}}){{/isMultipart}};
+      });
+      {{/isMultipart}}
+      {{^isMultipart}}
+      _bodyData = <String, dynamic>{
+        {{#formParams}}
+        {{^required}}{{^isNullable}}if ({{{paramName}}} != null) {{/isNullable}}{{/required}}r'{{{baseName}}}': {{>serialization/built_value/query_param}},
+        {{/formParams}}
+      };
+      {{/isMultipart}}
       {{/hasFormParams}}
       {{#bodyParam}}
       {{#isPrimitiveType}}

samples/openapi3/client/petstore/dart-dio-next/petstore_client_lib_fake/lib/src/api/another_fake_api.dart

@@ -54,9 +54,6 @@ class AnotherFakeApi {
       validateStatus: validateStatus,
     );
 
-    final _queryParameters = <String, dynamic>{
-    };
-
     dynamic _bodyData;
 
     try {
@@ -68,7 +65,6 @@ class AnotherFakeApi {
          requestOptions: _options.compose(
           _dio.options,
           _path,
-          queryParameters: _queryParameters,
         ),
         type: DioErrorType.other,
         error: error,
@@ -79,7 +75,6 @@ class AnotherFakeApi {
       _path,
       data: _bodyData,
       options: _options,
-      queryParameters: _queryParameters,
       cancelToken: cancelToken,
       onSendProgress: onSendProgress,
       onReceiveProgress: onReceiveProgress,

samples/openapi3/client/petstore/dart-dio-next/petstore_client_lib_fake/lib/src/api/default_api.dart

@@ -51,13 +51,9 @@ class DefaultApi {
       validateStatus: validateStatus,
     );
 
-    final _queryParameters = <String, dynamic>{
-    };
-
     final _response = await _dio.request<Object>(
       _path,
       options: _options,
-      queryParameters: _queryParameters,
       cancelToken: cancelToken,
       onSendProgress: onSendProgress,
       onReceiveProgress: onReceiveProgress,