From 77d9e91d10fd2f302dd02eb6bad87b6e35edb279 Mon Sep 17 00:00:00 2001
From: Inf1mum <vadim.lazuk@mail.ru>
Date: Tue, 3 Nov 2026 20:32:03 +0300
Subject: [PATCH 1/5] [dart-dio] fix: URI-encode path parameters

The query_param helpers pass strings through unchanged (built_value)
or interpolate raw values (freezed, json_serializable), so path
parameters containing '/', spaces or other reserved characters broke
the request path. Substitute path params through a new api/path_param
partial that wraps the value in Uri.encodeComponent for all three
serialization libraries.

Fixes #25527
---
 .../resources/dart/libraries/dio/api.mustache |  2 +-
 .../built_value/api/path_param.mustache       |  3 ++
 .../freezed/api/path_param.mustache           |  3 ++
 .../json_serializable/api/path_param.mustache |  3 ++
 .../dart/dio/DartDioClientCodegenTest.java    | 31 +++++++++++++++++++
 .../lib/src/api/pet_api.dart                  | 20 +++++++++---
 .../lib/src/api/store_api.dart                | 10 ++++--
 .../lib/src/api/user_api.dart                 | 15 +++++++--
 .../lib/src/api/pet_api.dart                  | 25 ++++++++++++---
 .../lib/src/api/store_api.dart                | 10 ++++--
 .../lib/src/api/user_api.dart                 | 15 +++++++--
 .../lib/src/api/pet_api.dart                  | 25 ++++++++++++---
 .../lib/src/api/store_api.dart                | 10 ++++--
 .../lib/src/api/user_api.dart                 | 15 +++++++--
 .../lib/src/api/pet_api.dart                  | 25 ++++++++++++---
 .../lib/src/api/store_api.dart                | 10 ++++--
 .../lib/src/api/user_api.dart                 | 15 +++++++--
 17 files changed, 197 insertions(+), 40 deletions(-)
 create mode 100644 modules/openapi-generator/src/main/resources/dart/libraries/dio/serialization/built_value/api/path_param.mustache
 create mode 100644 modules/openapi-generator/src/main/resources/dart/libraries/dio/serialization/freezed/api/path_param.mustache
 create mode 100644 modules/openapi-generator/src/main/resources/dart/libraries/dio/serialization/json_serializable/api/path_param.mustache

diff --git a/modules/openapi-generator/src/main/resources/dart/libraries/dio/api.mustache b/modules/openapi-generator/src/main/resources/dart/libraries/dio/api.mustache
index ac0e989c6141..1914de69254d 100644
--- a/modules/openapi-generator/src/main/resources/dart/libraries/dio/api.mustache
+++ b/modules/openapi-generator/src/main/resources/dart/libraries/dio/api.mustache
@@ -51,7 +51,7 @@ class {{classname}} {
     ProgressCallback? onSendProgress,
     ProgressCallback? onReceiveProgress,
   }) async {
-    final _path = r'{{{path}}}'{{#pathParams}}.replaceAll('{' r'{{{baseName}}}' '}', {{#includeLibraryTemplate}}api/query_param{{/includeLibraryTemplate}}.toString()){{/pathParams}};
+    final _path = r'{{{path}}}'{{#pathParams}}.replaceAll('{' r'{{{baseName}}}' '}', {{#includeLibraryTemplate}}api/path_param{{/includeLibraryTemplate}},){{/pathParams}};
     final _options = Options(
       method: r'{{#lambda.uppercase}}{{httpMethod}}{{/lambda.uppercase}}',
       {{#isResponseFile}}
diff --git a/modules/openapi-generator/src/main/resources/dart/libraries/dio/serialization/built_value/api/path_param.mustache b/modules/openapi-generator/src/main/resources/dart/libraries/dio/serialization/built_value/api/path_param.mustache
new file mode 100644
index 000000000000..8241f8e9914d
--- /dev/null
+++ b/modules/openapi-generator/src/main/resources/dart/libraries/dio/serialization/built_value/api/path_param.mustache
@@ -0,0 +1,3 @@
+Uri.encodeComponent(
+  {{#includeLibraryTemplate}}api/query_param{{/includeLibraryTemplate}}.toString(),
+)
diff --git a/modules/openapi-generator/src/main/resources/dart/libraries/dio/serialization/freezed/api/path_param.mustache b/modules/openapi-generator/src/main/resources/dart/libraries/dio/serialization/freezed/api/path_param.mustache
new file mode 100644
index 000000000000..8241f8e9914d
--- /dev/null
+++ b/modules/openapi-generator/src/main/resources/dart/libraries/dio/serialization/freezed/api/path_param.mustache
@@ -0,0 +1,3 @@
+Uri.encodeComponent(
+  {{#includeLibraryTemplate}}api/query_param{{/includeLibraryTemplate}}.toString(),
+)
diff --git a/modules/openapi-generator/src/main/resources/dart/libraries/dio/serialization/json_serializable/api/path_param.mustache b/modules/openapi-generator/src/main/resources/dart/libraries/dio/serialization/json_serializable/api/path_param.mustache
new file mode 100644
index 000000000000..8241f8e9914d
--- /dev/null
+++ b/modules/openapi-generator/src/main/resources/dart/libraries/dio/serialization/json_serializable/api/path_param.mustache
@@ -0,0 +1,3 @@
+Uri.encodeComponent(
+  {{#includeLibraryTemplate}}api/query_param{{/includeLibraryTemplate}}.toString(),
+)
diff --git a/modules/openapi-generator/src/test/java/org/openapitools/codegen/dart/dio/DartDioClientCodegenTest.java b/modules/openapi-generator/src/test/java/org/openapitools/codegen/dart/dio/DartDioClientCodegenTest.java
index acdf8de1cffc..c4f74ec7014f 100644
--- a/modules/openapi-generator/src/test/java/org/openapitools/codegen/dart/dio/DartDioClientCodegenTest.java
+++ b/modules/openapi-generator/src/test/java/org/openapitools/codegen/dart/dio/DartDioClientCodegenTest.java
@@ -471,6 +471,37 @@ public void testFreezedIgnoresUseOptional() throws IOException {
         TestUtils.assertFileNotContains(output.toPath().resolve("lib/src/model/pet.dart"), "Optional<");
     }
 
+    /**
+     * Path parameters must be URI-encoded as path components: the query_param helpers pass
+     * strings through unchanged, so a value containing '/' or spaces would otherwise break
+     * the request path.
+     */
+    @Test
+    public void testPathParamsAreUriEncoded() throws IOException {
+        for (Object[] libraryOption : serializationLibraries()) {
+            String serializationLibrary = (String) libraryOption[0];
+            File output = Files.createTempDirectory("test").toFile();
+            output.deleteOnExit();
+
+            final CodegenConfigurator configurator = new CodegenConfigurator()
+                    .setGeneratorName("dart-dio")
+                    .setInputSpec("src/test/resources/3_0/petstore.yaml")
+                    .setOutputDir(output.getAbsolutePath().replace("\\", "/"))
+                    .addAdditionalProperty(CodegenConstants.SERIALIZATION_LIBRARY, serializationLibrary);
+
+            ClientOptInput opts = configurator.toClientOptInput();
+            Generator generator = new DefaultGenerator().opts(opts);
+            List<File> files = generator.generate();
+            files.forEach(File::deleteOnExit);
+
+            Path petApi = output.toPath().resolve("lib/src/api/pet_api.dart");
+            String content = Files.readString(petApi, StandardCharsets.UTF_8);
+            Assert.assertTrue(content.contains(".replaceAll("), content);
+            Assert.assertTrue(content.contains("Uri.encodeComponent("),
+                    "path parameter should be URI-encoded in " + serializationLibrary + ": " + content);
+        }
+    }
+
     private Path generateFormParamsClient(String serializationLibrary) throws IOException {
         File output = Files.createTempDirectory("test").toFile();
         output.deleteOnExit();
diff --git a/samples/openapi3/client/petstore/dart-dio/petstore-timemachine/lib/src/api/pet_api.dart b/samples/openapi3/client/petstore/dart-dio/petstore-timemachine/lib/src/api/pet_api.dart
index 8aaf646e3051..8f6b3d378552 100644
--- a/samples/openapi3/client/petstore/dart-dio/petstore-timemachine/lib/src/api/pet_api.dart
+++ b/samples/openapi3/client/petstore/dart-dio/petstore-timemachine/lib/src/api/pet_api.dart
@@ -146,7 +146,10 @@ class PetApi {
     ProgressCallback? onSendProgress,
     ProgressCallback? onReceiveProgress,
   }) async {
-    final _path = r'/pet/{petId}'.replaceAll('{' r'petId' '}', encodeQueryParameter(_serializers, petId, const FullType(int)).toString());
+    final _path = r'/pet/{petId}'.replaceAll('{' r'petId' '}', Uri.encodeComponent(
+  encodeQueryParameter(_serializers, petId, const FullType(int)).toString(),
+)
+,);
     final _options = Options(
       method: r'DELETE',
       headers: <String, dynamic>{
@@ -370,7 +373,10 @@ class PetApi {
     ProgressCallback? onSendProgress,
     ProgressCallback? onReceiveProgress,
   }) async {
-    final _path = r'/pet/{petId}'.replaceAll('{' r'petId' '}', encodeQueryParameter(_serializers, petId, const FullType(int)).toString());
+    final _path = r'/pet/{petId}'.replaceAll('{' r'petId' '}', Uri.encodeComponent(
+  encodeQueryParameter(_serializers, petId, const FullType(int)).toString(),
+)
+,);
     final _options = Options(
       method: r'GET',
       headers: <String, dynamic>{
@@ -558,7 +564,10 @@ class PetApi {
     ProgressCallback? onSendProgress,
     ProgressCallback? onReceiveProgress,
   }) async {
-    final _path = r'/pet/{petId}'.replaceAll('{' r'petId' '}', encodeQueryParameter(_serializers, petId, const FullType(int)).toString());
+    final _path = r'/pet/{petId}'.replaceAll('{' r'petId' '}', Uri.encodeComponent(
+  encodeQueryParameter(_serializers, petId, const FullType(int)).toString(),
+)
+,);
     final _options = Options(
       method: r'POST',
       headers: <String, dynamic>{
@@ -636,7 +645,10 @@ class PetApi {
     ProgressCallback? onSendProgress,
     ProgressCallback? onReceiveProgress,
   }) async {
-    final _path = r'/pet/{petId}/uploadImage'.replaceAll('{' r'petId' '}', encodeQueryParameter(_serializers, petId, const FullType(int)).toString());
+    final _path = r'/pet/{petId}/uploadImage'.replaceAll('{' r'petId' '}', Uri.encodeComponent(
+  encodeQueryParameter(_serializers, petId, const FullType(int)).toString(),
+)
+,);
     final _options = Options(
       method: r'POST',
       headers: <String, dynamic>{
diff --git a/samples/openapi3/client/petstore/dart-dio/petstore-timemachine/lib/src/api/store_api.dart b/samples/openapi3/client/petstore/dart-dio/petstore-timemachine/lib/src/api/store_api.dart
index 5ad35b28d39a..ce3dff4b1aee 100644
--- a/samples/openapi3/client/petstore/dart-dio/petstore-timemachine/lib/src/api/store_api.dart
+++ b/samples/openapi3/client/petstore/dart-dio/petstore-timemachine/lib/src/api/store_api.dart
@@ -43,7 +43,10 @@ class StoreApi {
     ProgressCallback? onSendProgress,
     ProgressCallback? onReceiveProgress,
   }) async {
-    final _path = r'/store/order/{orderId}'.replaceAll('{' r'orderId' '}', encodeQueryParameter(_serializers, orderId, const FullType(String)).toString());
+    final _path = r'/store/order/{orderId}'.replaceAll('{' r'orderId' '}', Uri.encodeComponent(
+  encodeQueryParameter(_serializers, orderId, const FullType(String)).toString(),
+)
+,);
     final _options = Options(
       method: r'DELETE',
       headers: <String, dynamic>{
@@ -170,7 +173,10 @@ class StoreApi {
     ProgressCallback? onSendProgress,
     ProgressCallback? onReceiveProgress,
   }) async {
-    final _path = r'/store/order/{orderId}'.replaceAll('{' r'orderId' '}', encodeQueryParameter(_serializers, orderId, const FullType(int)).toString());
+    final _path = r'/store/order/{orderId}'.replaceAll('{' r'orderId' '}', Uri.encodeComponent(
+  encodeQueryParameter(_serializers, orderId, const FullType(int)).toString(),
+)
+,);
     final _options = Options(
       method: r'GET',
       headers: <String, dynamic>{
diff --git a/samples/openapi3/client/petstore/dart-dio/petstore-timemachine/lib/src/api/user_api.dart b/samples/openapi3/client/petstore/dart-dio/petstore-timemachine/lib/src/api/user_api.dart
index c052b91ccf63..68ee84324d50 100644
--- a/samples/openapi3/client/petstore/dart-dio/petstore-timemachine/lib/src/api/user_api.dart
+++ b/samples/openapi3/client/petstore/dart-dio/petstore-timemachine/lib/src/api/user_api.dart
@@ -266,7 +266,10 @@ class UserApi {
     ProgressCallback? onSendProgress,
     ProgressCallback? onReceiveProgress,
   }) async {
-    final _path = r'/user/{username}'.replaceAll('{' r'username' '}', encodeQueryParameter(_serializers, username, const FullType(String)).toString());
+    final _path = r'/user/{username}'.replaceAll('{' r'username' '}', Uri.encodeComponent(
+  encodeQueryParameter(_serializers, username, const FullType(String)).toString(),
+)
+,);
     final _options = Options(
       method: r'DELETE',
       headers: <String, dynamic>{
@@ -320,7 +323,10 @@ class UserApi {
     ProgressCallback? onSendProgress,
     ProgressCallback? onReceiveProgress,
   }) async {
-    final _path = r'/user/{username}'.replaceAll('{' r'username' '}', encodeQueryParameter(_serializers, username, const FullType(String)).toString());
+    final _path = r'/user/{username}'.replaceAll('{' r'username' '}', Uri.encodeComponent(
+  encodeQueryParameter(_serializers, username, const FullType(String)).toString(),
+)
+,);
     final _options = Options(
       method: r'GET',
       headers: <String, dynamic>{
@@ -529,7 +535,10 @@ class UserApi {
     ProgressCallback? onSendProgress,
     ProgressCallback? onReceiveProgress,
   }) async {
-    final _path = r'/user/{username}'.replaceAll('{' r'username' '}', encodeQueryParameter(_serializers, username, const FullType(String)).toString());
+    final _path = r'/user/{username}'.replaceAll('{' r'username' '}', Uri.encodeComponent(
+  encodeQueryParameter(_serializers, username, const FullType(String)).toString(),
+)
+,);
     final _options = Options(
       method: r'PUT',
       headers: <String, dynamic>{
diff --git a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-freezed/lib/src/api/pet_api.dart b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-freezed/lib/src/api/pet_api.dart
index ada4f50fa6bb..ba954c9411e1 100644
--- a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-freezed/lib/src/api/pet_api.dart
+++ b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-freezed/lib/src/api/pet_api.dart
@@ -118,7 +118,10 @@ class PetApi {
     ProgressCallback? onSendProgress,
     ProgressCallback? onReceiveProgress,
   }) async {
-    final _path = r'/pet/{petId}'.replaceAll('{' r'petId' '}', petId.toString());
+    final _path = r'/pet/{petId}'.replaceAll('{' r'petId' '}', Uri.encodeComponent(
+  petId.toString(),
+)
+,);
     final _options = Options(
       method: r'DELETE',
       headers: <String, dynamic>{
@@ -336,7 +339,10 @@ _responseData = rawData == null ? null : deserialize<Set<Pet>, Pet>(rawData, 'Se
     ProgressCallback? onSendProgress,
     ProgressCallback? onReceiveProgress,
   }) async {
-    final _path = r'/pet/{petId}'.replaceAll('{' r'petId' '}', petId.toString());
+    final _path = r'/pet/{petId}'.replaceAll('{' r'petId' '}', Uri.encodeComponent(
+  petId.toString(),
+)
+,);
     final _options = Options(
       method: r'GET',
       headers: <String, dynamic>{
@@ -494,7 +500,10 @@ _responseData = rawData == null ? null : deserialize<Pet, Pet>(rawData, 'Pet', g
     ProgressCallback? onSendProgress,
     ProgressCallback? onReceiveProgress,
   }) async {
-    final _path = r'/pet/{petId}'.replaceAll('{' r'petId' '}', petId.toString());
+    final _path = r'/pet/{petId}'.replaceAll('{' r'petId' '}', Uri.encodeComponent(
+  petId.toString(),
+)
+,);
     final _options = Options(
       method: r'POST',
       headers: <String, dynamic>{
@@ -572,7 +581,10 @@ _responseData = rawData == null ? null : deserialize<Pet, Pet>(rawData, 'Pet', g
     ProgressCallback? onSendProgress,
     ProgressCallback? onReceiveProgress,
   }) async {
-    final _path = r'/pet/{petId}/uploadImage'.replaceAll('{' r'petId' '}', petId.toString());
+    final _path = r'/pet/{petId}/uploadImage'.replaceAll('{' r'petId' '}', Uri.encodeComponent(
+  petId.toString(),
+)
+,);
     final _options = Options(
       method: r'POST',
       headers: <String, dynamic>{
@@ -675,7 +687,10 @@ _responseData = rawData == null ? null : deserialize<ApiResponse, ApiResponse>(r
     ProgressCallback? onSendProgress,
     ProgressCallback? onReceiveProgress,
   }) async {
-    final _path = r'/fake/{petId}/uploadImageWithRequiredFile'.replaceAll('{' r'petId' '}', petId.toString());
+    final _path = r'/fake/{petId}/uploadImageWithRequiredFile'.replaceAll('{' r'petId' '}', Uri.encodeComponent(
+  petId.toString(),
+)
+,);
     final _options = Options(
       method: r'POST',
       headers: <String, dynamic>{
diff --git a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-freezed/lib/src/api/store_api.dart b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-freezed/lib/src/api/store_api.dart
index f3d48dc3d1f1..aee10338f9a5 100644
--- a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-freezed/lib/src/api/store_api.dart
+++ b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-freezed/lib/src/api/store_api.dart
@@ -40,7 +40,10 @@ class StoreApi {
     ProgressCallback? onSendProgress,
     ProgressCallback? onReceiveProgress,
   }) async {
-    final _path = r'/store/order/{order_id}'.replaceAll('{' r'order_id' '}', orderId.toString());
+    final _path = r'/store/order/{order_id}'.replaceAll('{' r'order_id' '}', Uri.encodeComponent(
+  orderId.toString(),
+)
+,);
     final _options = Options(
       method: r'DELETE',
       headers: <String, dynamic>{
@@ -164,7 +167,10 @@ _responseData = rawData == null ? null : deserialize<Map<String, int>, int>(rawD
     ProgressCallback? onSendProgress,
     ProgressCallback? onReceiveProgress,
   }) async {
-    final _path = r'/store/order/{order_id}'.replaceAll('{' r'order_id' '}', orderId.toString());
+    final _path = r'/store/order/{order_id}'.replaceAll('{' r'order_id' '}', Uri.encodeComponent(
+  orderId.toString(),
+)
+,);
     final _options = Options(
       method: r'GET',
       headers: <String, dynamic>{
diff --git a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-freezed/lib/src/api/user_api.dart b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-freezed/lib/src/api/user_api.dart
index ad5d89369ea4..1053514435ca 100644
--- a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-freezed/lib/src/api/user_api.dart
+++ b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-freezed/lib/src/api/user_api.dart
@@ -250,7 +250,10 @@ class UserApi {
     ProgressCallback? onSendProgress,
     ProgressCallback? onReceiveProgress,
   }) async {
-    final _path = r'/user/{username}'.replaceAll('{' r'username' '}', username.toString());
+    final _path = r'/user/{username}'.replaceAll('{' r'username' '}', Uri.encodeComponent(
+  username.toString(),
+)
+,);
     final _options = Options(
       method: r'DELETE',
       headers: <String, dynamic>{
@@ -297,7 +300,10 @@ class UserApi {
     ProgressCallback? onSendProgress,
     ProgressCallback? onReceiveProgress,
   }) async {
-    final _path = r'/user/{username}'.replaceAll('{' r'username' '}', username.toString());
+    final _path = r'/user/{username}'.replaceAll('{' r'username' '}', Uri.encodeComponent(
+  username.toString(),
+)
+,);
     final _options = Options(
       method: r'GET',
       headers: <String, dynamic>{
@@ -496,7 +502,10 @@ _responseData = rawData == null ? null : deserialize<String, String>(rawData, 'S
     ProgressCallback? onSendProgress,
     ProgressCallback? onReceiveProgress,
   }) async {
-    final _path = r'/user/{username}'.replaceAll('{' r'username' '}', username.toString());
+    final _path = r'/user/{username}'.replaceAll('{' r'username' '}', Uri.encodeComponent(
+  username.toString(),
+)
+,);
     final _options = Options(
       method: r'PUT',
       headers: <String, dynamic>{
diff --git a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/api/pet_api.dart b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/api/pet_api.dart
index 60aaece86905..d2f23f84ef7a 100644
--- a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/api/pet_api.dart
+++ b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/api/pet_api.dart
@@ -114,7 +114,10 @@ class PetApi {
     ProgressCallback? onSendProgress,
     ProgressCallback? onReceiveProgress,
   }) async {
-    final _path = r'/pet/{petId}'.replaceAll('{' r'petId' '}', petId.toString());
+    final _path = r'/pet/{petId}'.replaceAll('{' r'petId' '}', Uri.encodeComponent(
+  petId.toString(),
+)
+,);
     final _options = Options(
       method: r'DELETE',
       headers: <String, dynamic>{
@@ -332,7 +335,10 @@ _responseData = rawData == null ? null : deserialize<Set<Pet>, Pet>(rawData, 'Se
     ProgressCallback? onSendProgress,
     ProgressCallback? onReceiveProgress,
   }) async {
-    final _path = r'/pet/{petId}'.replaceAll('{' r'petId' '}', petId.toString());
+    final _path = r'/pet/{petId}'.replaceAll('{' r'petId' '}', Uri.encodeComponent(
+  petId.toString(),
+)
+,);
     final _options = Options(
       method: r'GET',
       headers: <String, dynamic>{
@@ -486,7 +492,10 @@ _responseData = rawData == null ? null : deserialize<Pet, Pet>(rawData, 'Pet', g
     ProgressCallback? onSendProgress,
     ProgressCallback? onReceiveProgress,
   }) async {
-    final _path = r'/pet/{petId}'.replaceAll('{' r'petId' '}', petId.toString());
+    final _path = r'/pet/{petId}'.replaceAll('{' r'petId' '}', Uri.encodeComponent(
+  petId.toString(),
+)
+,);
     final _options = Options(
       method: r'POST',
       headers: <String, dynamic>{
@@ -564,7 +573,10 @@ _responseData = rawData == null ? null : deserialize<Pet, Pet>(rawData, 'Pet', g
     ProgressCallback? onSendProgress,
     ProgressCallback? onReceiveProgress,
   }) async {
-    final _path = r'/pet/{petId}/uploadImage'.replaceAll('{' r'petId' '}', petId.toString());
+    final _path = r'/pet/{petId}/uploadImage'.replaceAll('{' r'petId' '}', Uri.encodeComponent(
+  petId.toString(),
+)
+,);
     final _options = Options(
       method: r'POST',
       headers: <String, dynamic>{
@@ -667,7 +679,10 @@ _responseData = rawData == null ? null : deserialize<ApiResponse, ApiResponse>(r
     ProgressCallback? onSendProgress,
     ProgressCallback? onReceiveProgress,
   }) async {
-    final _path = r'/fake/{petId}/uploadImageWithRequiredFile'.replaceAll('{' r'petId' '}', petId.toString());
+    final _path = r'/fake/{petId}/uploadImageWithRequiredFile'.replaceAll('{' r'petId' '}', Uri.encodeComponent(
+  petId.toString(),
+)
+,);
     final _options = Options(
       method: r'POST',
       headers: <String, dynamic>{
diff --git a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/api/store_api.dart b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/api/store_api.dart
index 272e45a0ef6c..b52b8b8dea2e 100644
--- a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/api/store_api.dart
+++ b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/api/store_api.dart
@@ -40,7 +40,10 @@ class StoreApi {
     ProgressCallback? onSendProgress,
     ProgressCallback? onReceiveProgress,
   }) async {
-    final _path = r'/store/order/{order_id}'.replaceAll('{' r'order_id' '}', orderId.toString());
+    final _path = r'/store/order/{order_id}'.replaceAll('{' r'order_id' '}', Uri.encodeComponent(
+  orderId.toString(),
+)
+,);
     final _options = Options(
       method: r'DELETE',
       headers: <String, dynamic>{
@@ -164,7 +167,10 @@ _responseData = rawData == null ? null : deserialize<Map<String, int>, int>(rawD
     ProgressCallback? onSendProgress,
     ProgressCallback? onReceiveProgress,
   }) async {
-    final _path = r'/store/order/{order_id}'.replaceAll('{' r'order_id' '}', orderId.toString());
+    final _path = r'/store/order/{order_id}'.replaceAll('{' r'order_id' '}', Uri.encodeComponent(
+  orderId.toString(),
+)
+,);
     final _options = Options(
       method: r'GET',
       headers: <String, dynamic>{
diff --git a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/api/user_api.dart b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/api/user_api.dart
index 87ceeccc6b4a..5f5717b8f9b0 100644
--- a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/api/user_api.dart
+++ b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/api/user_api.dart
@@ -238,7 +238,10 @@ class UserApi {
     ProgressCallback? onSendProgress,
     ProgressCallback? onReceiveProgress,
   }) async {
-    final _path = r'/user/{username}'.replaceAll('{' r'username' '}', username.toString());
+    final _path = r'/user/{username}'.replaceAll('{' r'username' '}', Uri.encodeComponent(
+  username.toString(),
+)
+,);
     final _options = Options(
       method: r'DELETE',
       headers: <String, dynamic>{
@@ -285,7 +288,10 @@ class UserApi {
     ProgressCallback? onSendProgress,
     ProgressCallback? onReceiveProgress,
   }) async {
-    final _path = r'/user/{username}'.replaceAll('{' r'username' '}', username.toString());
+    final _path = r'/user/{username}'.replaceAll('{' r'username' '}', Uri.encodeComponent(
+  username.toString(),
+)
+,);
     final _options = Options(
       method: r'GET',
       headers: <String, dynamic>{
@@ -484,7 +490,10 @@ _responseData = rawData == null ? null : deserialize<String, String>(rawData, 'S
     ProgressCallback? onSendProgress,
     ProgressCallback? onReceiveProgress,
   }) async {
-    final _path = r'/user/{username}'.replaceAll('{' r'username' '}', username.toString());
+    final _path = r'/user/{username}'.replaceAll('{' r'username' '}', Uri.encodeComponent(
+  username.toString(),
+)
+,);
     final _options = Options(
       method: r'PUT',
       headers: <String, dynamic>{
diff --git a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake/lib/src/api/pet_api.dart b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake/lib/src/api/pet_api.dart
index a4da1c5ff6db..a8c1527fa1ff 100644
--- a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake/lib/src/api/pet_api.dart
+++ b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake/lib/src/api/pet_api.dart
@@ -118,7 +118,10 @@ class PetApi {
     ProgressCallback? onSendProgress,
     ProgressCallback? onReceiveProgress,
   }) async {
-    final _path = r'/pet/{petId}'.replaceAll('{' r'petId' '}', encodeQueryParameter(_serializers, petId, const FullType(int)).toString());
+    final _path = r'/pet/{petId}'.replaceAll('{' r'petId' '}', Uri.encodeComponent(
+  encodeQueryParameter(_serializers, petId, const FullType(int)).toString(),
+)
+,);
     final _options = Options(
       method: r'DELETE',
       headers: <String, dynamic>{
@@ -342,7 +345,10 @@ class PetApi {
     ProgressCallback? onSendProgress,
     ProgressCallback? onReceiveProgress,
   }) async {
-    final _path = r'/pet/{petId}'.replaceAll('{' r'petId' '}', encodeQueryParameter(_serializers, petId, const FullType(int)).toString());
+    final _path = r'/pet/{petId}'.replaceAll('{' r'petId' '}', Uri.encodeComponent(
+  encodeQueryParameter(_serializers, petId, const FullType(int)).toString(),
+)
+,);
     final _options = Options(
       method: r'GET',
       headers: <String, dynamic>{
@@ -500,7 +506,10 @@ class PetApi {
     ProgressCallback? onSendProgress,
     ProgressCallback? onReceiveProgress,
   }) async {
-    final _path = r'/pet/{petId}'.replaceAll('{' r'petId' '}', encodeQueryParameter(_serializers, petId, const FullType(int)).toString());
+    final _path = r'/pet/{petId}'.replaceAll('{' r'petId' '}', Uri.encodeComponent(
+  encodeQueryParameter(_serializers, petId, const FullType(int)).toString(),
+)
+,);
     final _options = Options(
       method: r'POST',
       headers: <String, dynamic>{
@@ -578,7 +587,10 @@ class PetApi {
     ProgressCallback? onSendProgress,
     ProgressCallback? onReceiveProgress,
   }) async {
-    final _path = r'/pet/{petId}/uploadImage'.replaceAll('{' r'petId' '}', encodeQueryParameter(_serializers, petId, const FullType(int)).toString());
+    final _path = r'/pet/{petId}/uploadImage'.replaceAll('{' r'petId' '}', Uri.encodeComponent(
+  encodeQueryParameter(_serializers, petId, const FullType(int)).toString(),
+)
+,);
     final _options = Options(
       method: r'POST',
       headers: <String, dynamic>{
@@ -684,7 +696,10 @@ class PetApi {
     ProgressCallback? onSendProgress,
     ProgressCallback? onReceiveProgress,
   }) async {
-    final _path = r'/fake/{petId}/uploadImageWithRequiredFile'.replaceAll('{' r'petId' '}', encodeQueryParameter(_serializers, petId, const FullType(int)).toString());
+    final _path = r'/fake/{petId}/uploadImageWithRequiredFile'.replaceAll('{' r'petId' '}', Uri.encodeComponent(
+  encodeQueryParameter(_serializers, petId, const FullType(int)).toString(),
+)
+,);
     final _options = Options(
       method: r'POST',
       headers: <String, dynamic>{
diff --git a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake/lib/src/api/store_api.dart b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake/lib/src/api/store_api.dart
index 6f519ff8ee51..1a3e0765284e 100644
--- a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake/lib/src/api/store_api.dart
+++ b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake/lib/src/api/store_api.dart
@@ -43,7 +43,10 @@ class StoreApi {
     ProgressCallback? onSendProgress,
     ProgressCallback? onReceiveProgress,
   }) async {
-    final _path = r'/store/order/{order_id}'.replaceAll('{' r'order_id' '}', encodeQueryParameter(_serializers, orderId, const FullType(String)).toString());
+    final _path = r'/store/order/{order_id}'.replaceAll('{' r'order_id' '}', Uri.encodeComponent(
+  encodeQueryParameter(_serializers, orderId, const FullType(String)).toString(),
+)
+,);
     final _options = Options(
       method: r'DELETE',
       headers: <String, dynamic>{
@@ -170,7 +173,10 @@ class StoreApi {
     ProgressCallback? onSendProgress,
     ProgressCallback? onReceiveProgress,
   }) async {
-    final _path = r'/store/order/{order_id}'.replaceAll('{' r'order_id' '}', encodeQueryParameter(_serializers, orderId, const FullType(int)).toString());
+    final _path = r'/store/order/{order_id}'.replaceAll('{' r'order_id' '}', Uri.encodeComponent(
+  encodeQueryParameter(_serializers, orderId, const FullType(int)).toString(),
+)
+,);
     final _options = Options(
       method: r'GET',
       headers: <String, dynamic>{
diff --git a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake/lib/src/api/user_api.dart b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake/lib/src/api/user_api.dart
index 2a7e5132a60a..f9a4d0ca1615 100644
--- a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake/lib/src/api/user_api.dart
+++ b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake/lib/src/api/user_api.dart
@@ -244,7 +244,10 @@ class UserApi {
     ProgressCallback? onSendProgress,
     ProgressCallback? onReceiveProgress,
   }) async {
-    final _path = r'/user/{username}'.replaceAll('{' r'username' '}', encodeQueryParameter(_serializers, username, const FullType(String)).toString());
+    final _path = r'/user/{username}'.replaceAll('{' r'username' '}', Uri.encodeComponent(
+  encodeQueryParameter(_serializers, username, const FullType(String)).toString(),
+)
+,);
     final _options = Options(
       method: r'DELETE',
       headers: <String, dynamic>{
@@ -291,7 +294,10 @@ class UserApi {
     ProgressCallback? onSendProgress,
     ProgressCallback? onReceiveProgress,
   }) async {
-    final _path = r'/user/{username}'.replaceAll('{' r'username' '}', encodeQueryParameter(_serializers, username, const FullType(String)).toString());
+    final _path = r'/user/{username}'.replaceAll('{' r'username' '}', Uri.encodeComponent(
+  encodeQueryParameter(_serializers, username, const FullType(String)).toString(),
+)
+,);
     final _options = Options(
       method: r'GET',
       headers: <String, dynamic>{
@@ -493,7 +499,10 @@ class UserApi {
     ProgressCallback? onSendProgress,
     ProgressCallback? onReceiveProgress,
   }) async {
-    final _path = r'/user/{username}'.replaceAll('{' r'username' '}', encodeQueryParameter(_serializers, username, const FullType(String)).toString());
+    final _path = r'/user/{username}'.replaceAll('{' r'username' '}', Uri.encodeComponent(
+  encodeQueryParameter(_serializers, username, const FullType(String)).toString(),
+)
+,);
     final _options = Options(
       method: r'PUT',
       headers: <String, dynamic>{

From c55ffc3690f9df327cc0a91585c90cbb9a3c086f Mon Sep 17 00:00:00 2001
From: Inf1mum <vadim.lazuk@mail.ru>
Date: Tue, 3 Nov 2026 20:36:17 +0300
Subject: [PATCH 2/5] [ruby-nextgen] fix: always use explicit Zeitwerk loader
 with moduleName namespace

Zeitwerk::Loader.for_gem derives its namespace from gemName, so a
single-level moduleName that is not the camelized gemName (e.g.
gemName=things_api, moduleName=Things) autoloaded nothing. Drive
Zeitwerk explicitly with push_dir(namespace: self) in all cases -
the nested branch already did, and it never depended on the names
matching.

Fixes #24997
---
 .../main/resources/ruby-nextgen/gem.mustache  | 11 +++-----
 .../RubyNextgenClientCodegenTest.java         | 25 +++++++++++++++++++
 .../others/ruby-nextgen-qdrant/lib/qdrant.rb  | 11 +++++++-
 .../petstore/ruby-nextgen/lib/petstore.rb     | 11 +++++++-
 4 files changed, 48 insertions(+), 10 deletions(-)

diff --git a/modules/openapi-generator/src/main/resources/ruby-nextgen/gem.mustache b/modules/openapi-generator/src/main/resources/ruby-nextgen/gem.mustache
index e411a4277681..68ee988370d9 100644
--- a/modules/openapi-generator/src/main/resources/ruby-nextgen/gem.mustache
+++ b/modules/openapi-generator/src/main/resources/ruby-nextgen/gem.mustache
@@ -21,10 +21,9 @@ module {{moduleName}}
     attr_reader :loader
   end
 
-{{#moduleNameNested}}
-  # Nested moduleName: for_gem can't target a nested namespace, so drive Zeitwerk
-  # explicitly. The parent module(s) above are pre-defined so `module {{moduleName}}`
-  # (here and in every generated file) reopens rather than raising NameError.
+  # for_gem derives the namespace from gemName, which need not match moduleName (and
+  # can't target a nested one), so drive Zeitwerk explicitly. Any parent module(s) above
+  # are pre-defined so `module {{moduleName}}` reopens rather than raising NameError.
   @loader = Zeitwerk::Loader.new
   @loader.push_dir("#{__dir__}/{{gemName}}", namespace: self)
   # version.rb defines VERSION (not a `Version` class). for_gem's GemInflector special-cases
@@ -32,10 +31,6 @@ module {{moduleName}}
   # {{moduleName}}::VERSION available.
   @loader.ignore("#{__dir__}/{{gemName}}/version.rb")
   require_relative "{{gemName}}/version"
-{{/moduleNameNested}}
-{{^moduleNameNested}}
-  @loader = Zeitwerk::Loader.for_gem
-{{/moduleNameNested}}
 {{#zeitwerkInflections.0}}
   # Model names keep their acronym casing (e.g. HTTPConfig), but Zeitwerk's default
   # inflector would expect HttpConfig from the file name. Register the exceptions so
diff --git a/modules/openapi-generator/src/test/java/org/openapitools/codegen/rubynextgen/RubyNextgenClientCodegenTest.java b/modules/openapi-generator/src/test/java/org/openapitools/codegen/rubynextgen/RubyNextgenClientCodegenTest.java
index 4158d40b4961..d914f9527319 100644
--- a/modules/openapi-generator/src/test/java/org/openapitools/codegen/rubynextgen/RubyNextgenClientCodegenTest.java
+++ b/modules/openapi-generator/src/test/java/org/openapitools/codegen/rubynextgen/RubyNextgenClientCodegenTest.java
@@ -443,6 +443,31 @@ public void testAcronymModelsGetZeitwerkInflections() throws Exception {
                 "@two_fa_whitelist ||= DedicatedCloud::TwoFAWhitelist.new(@connection)");
     }
 
+    @Test
+    public void testZeitwerkLoaderWhenModuleNameDiffersFromGemName() throws Exception {
+        java.nio.file.Path target = java.nio.file.Files.createTempDirectory("test");
+        target.toFile().deleteOnExit();
+        org.openapitools.codegen.ClientOptInput input =
+                new org.openapitools.codegen.config.CodegenConfigurator()
+                        .setGeneratorName("ruby-nextgen")
+                        .setInputSpec("src/test/resources/3_0/ruby-nextgen/acronym.yaml")
+                        .setOutputDir(target.toString())
+                        // camelized gemName would be ThingsApi, but the namespace is Things:
+                        // Zeitwerk::Loader.for_gem would target ThingsApi and autoload nothing
+                        .addAdditionalProperty("gemName", "things_api")
+                        .addAdditionalProperty("moduleName", "Things")
+                        .toClientOptInput();
+        new org.openapitools.codegen.DefaultGenerator(false).opts(input).generate();
+
+        // the explicit loader targets the moduleName namespace regardless of gemName
+        org.openapitools.codegen.TestUtils.assertFileContains(
+                target.resolve("lib/things_api.rb"),
+                "Zeitwerk::Loader.new",
+                "@loader.push_dir(\"#{__dir__}/things_api\", namespace: self)");
+        org.openapitools.codegen.TestUtils.assertFileNotContains(
+                target.resolve("lib/things_api.rb"), "Zeitwerk::Loader.for_gem");
+    }
+
     @Test
     public void testNestedResourcesAreReachableFromClient() throws Exception {
         java.nio.file.Path target = java.nio.file.Files.createTempDirectory("test");
diff --git a/samples/client/others/ruby-nextgen-qdrant/lib/qdrant.rb b/samples/client/others/ruby-nextgen-qdrant/lib/qdrant.rb
index 5be13f72f31e..612cc605f078 100644
--- a/samples/client/others/ruby-nextgen-qdrant/lib/qdrant.rb
+++ b/samples/client/others/ruby-nextgen-qdrant/lib/qdrant.rb
@@ -20,7 +20,16 @@ class << self
     attr_reader :loader
   end
 
-  @loader = Zeitwerk::Loader.for_gem
+  # for_gem derives the namespace from gemName, which need not match moduleName (and
+  # can't target a nested one), so drive Zeitwerk explicitly. Any parent module(s) above
+  # are pre-defined so `module Qdrant` reopens rather than raising NameError.
+  @loader = Zeitwerk::Loader.new
+  @loader.push_dir("#{__dir__}/qdrant", namespace: self)
+  # version.rb defines VERSION (not a `Version` class). for_gem's GemInflector special-cases
+  # this; a plain Loader doesn't, so ignore it for autoloading and require it directly to keep
+  # Qdrant::VERSION available.
+  @loader.ignore("#{__dir__}/qdrant/version.rb")
+  require_relative "qdrant/version"
   # The `api/` directory on disk is fixed regardless of the `apiNamespace` CliOption,
   # but api.mustache only nests classes under an `Api` module when the wrapper is
   # enabled (true). When it's disabled, tell Zeitwerk to collapse
diff --git a/samples/client/petstore/ruby-nextgen/lib/petstore.rb b/samples/client/petstore/ruby-nextgen/lib/petstore.rb
index 19e492b7a84c..8ee009b7e8c1 100644
--- a/samples/client/petstore/ruby-nextgen/lib/petstore.rb
+++ b/samples/client/petstore/ruby-nextgen/lib/petstore.rb
@@ -19,7 +19,16 @@ class << self
     attr_reader :loader
   end
 
-  @loader = Zeitwerk::Loader.for_gem
+  # for_gem derives the namespace from gemName, which need not match moduleName (and
+  # can't target a nested one), so drive Zeitwerk explicitly. Any parent module(s) above
+  # are pre-defined so `module Petstore` reopens rather than raising NameError.
+  @loader = Zeitwerk::Loader.new
+  @loader.push_dir("#{__dir__}/petstore", namespace: self)
+  # version.rb defines VERSION (not a `Version` class). for_gem's GemInflector special-cases
+  # this; a plain Loader doesn't, so ignore it for autoloading and require it directly to keep
+  # Petstore::VERSION available.
+  @loader.ignore("#{__dir__}/petstore/version.rb")
+  require_relative "petstore/version"
   # The `api/` directory on disk is fixed regardless of the `apiNamespace` CliOption,
   # but api.mustache only nests classes under an `Api` module when the wrapper is
   # enabled (true). When it's disabled, tell Zeitwerk to collapse

From 8349ba66f0f9b7e35cf18a624e877e00486c091a Mon Sep 17 00:00:00 2001
From: Inf1mum <vadim.lazuk@mail.ru>
Date: Tue, 3 Nov 2026 23:42:45 +0300
Subject: [PATCH 3/5] [dart-dio] pin source_helper <1.4.0 in the freezed
 variant

source_helper 1.4.0 (published 2026-10-19) added extension members
that clash with json_serializable 6.x's internal copies, breaking
compilation of the build_runner build script ('toStringNonNullable is
defined in multiple extensions'). The json_serializable variant is
unaffected because copy_with_extension_gen's source_gen constraint
holds source_helper below 1.4.0; the freezed variant has no such
guard and floated to 1.4.0.

Verified with Dart 3.9: pub get resolves source_helper 1.3.13,
build_runner builds, dart test passes (190 tests).
---
 .../src/main/resources/dart/libraries/dio/pubspec.mustache   | 5 +++++
 .../dart-dio/petstore_client_lib_fake-freezed/pubspec.yaml   | 5 +++++
 2 files changed, 10 insertions(+)

diff --git a/modules/openapi-generator/src/main/resources/dart/libraries/dio/pubspec.mustache b/modules/openapi-generator/src/main/resources/dart/libraries/dio/pubspec.mustache
index 1d7352f8cc26..0fd014044c8e 100644
--- a/modules/openapi-generator/src/main/resources/dart/libraries/dio/pubspec.mustache
+++ b/modules/openapi-generator/src/main/resources/dart/libraries/dio/pubspec.mustache
@@ -54,5 +54,10 @@ dev_dependencies:
   build_runner: any
   freezed: '^3.0.0'
   json_serializable: '^6.9.3'
+  # unlike the json_serializable variant, this one has no copy_with_extension_gen
+  # whose source_gen constraint would hold source_helper back; source_helper 1.4.0
+  # added extension members that clash with json_serializable 6.x's internal
+  # copies and break the build_runner build script, so hold it below 1.4.0
+  source_helper: '>=1.3.13 <1.4.0'
 {{/useFreezed}}
   test: '^1.16.0'
diff --git a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-freezed/pubspec.yaml b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-freezed/pubspec.yaml
index 5bde8eacee67..3615b34d416c 100644
--- a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-freezed/pubspec.yaml
+++ b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-freezed/pubspec.yaml
@@ -16,4 +16,9 @@ dev_dependencies:
   build_runner: any
   freezed: '^3.0.0'
   json_serializable: '^6.9.3'
+  # unlike the json_serializable variant, this one has no copy_with_extension_gen
+  # whose source_gen constraint would hold source_helper back; source_helper 1.4.0
+  # added extension members that clash with json_serializable 6.x's internal
+  # copies and break the build_runner build script, so hold it below 1.4.0
+  source_helper: '>=1.3.13 <1.4.0'
   test: '^1.16.0'

From d067857c6a0615b9ba44b4d066eb204cf0b60327 Mon Sep 17 00:00:00 2001
From: Inf1mum <vadim.lazuk@mail.ru>
Date: Tue, 3 Nov 2026 23:48:47 +0300
Subject: [PATCH 4/5] [dart-dio] single-line path_param template and stronger
 encoding test

- render Uri.encodeComponent on one line so generated paths keep the
  previous single-line style
- assert in testPathParamsAreUriEncoded that the number of
  Uri.encodeComponent calls equals the number of path substitutions in
  every generated api class, not just that one occurrence exists

Addresses review feedback in #25544.
---
 .../built_value/api/path_param.mustache       |  4 +--
 .../freezed/api/path_param.mustache           |  4 +--
 .../json_serializable/api/path_param.mustache |  4 +--
 .../dart/dio/DartDioClientCodegenTest.java    | 22 +++++++++++-----
 .../lib/src/api/pet_api.dart                  | 20 +++------------
 .../lib/src/api/store_api.dart                | 10 ++------
 .../lib/src/api/user_api.dart                 | 15 +++--------
 .../lib/src/api/pet_api.dart                  | 25 ++++---------------
 .../lib/src/api/store_api.dart                | 10 ++------
 .../lib/src/api/user_api.dart                 | 15 +++--------
 .../lib/src/api/pet_api.dart                  | 25 ++++---------------
 .../lib/src/api/store_api.dart                | 10 ++------
 .../lib/src/api/user_api.dart                 | 15 +++--------
 .../lib/src/api/pet_api.dart                  | 25 ++++---------------
 .../lib/src/api/store_api.dart                | 10 ++------
 .../lib/src/api/user_api.dart                 | 15 +++--------
 16 files changed, 58 insertions(+), 171 deletions(-)

diff --git a/modules/openapi-generator/src/main/resources/dart/libraries/dio/serialization/built_value/api/path_param.mustache b/modules/openapi-generator/src/main/resources/dart/libraries/dio/serialization/built_value/api/path_param.mustache
index 8241f8e9914d..1d633242d7cd 100644
--- a/modules/openapi-generator/src/main/resources/dart/libraries/dio/serialization/built_value/api/path_param.mustache
+++ b/modules/openapi-generator/src/main/resources/dart/libraries/dio/serialization/built_value/api/path_param.mustache
@@ -1,3 +1 @@
-Uri.encodeComponent(
-  {{#includeLibraryTemplate}}api/query_param{{/includeLibraryTemplate}}.toString(),
-)
+Uri.encodeComponent({{#includeLibraryTemplate}}api/query_param{{/includeLibraryTemplate}}.toString())
\ No newline at end of file
diff --git a/modules/openapi-generator/src/main/resources/dart/libraries/dio/serialization/freezed/api/path_param.mustache b/modules/openapi-generator/src/main/resources/dart/libraries/dio/serialization/freezed/api/path_param.mustache
index 8241f8e9914d..1d633242d7cd 100644
--- a/modules/openapi-generator/src/main/resources/dart/libraries/dio/serialization/freezed/api/path_param.mustache
+++ b/modules/openapi-generator/src/main/resources/dart/libraries/dio/serialization/freezed/api/path_param.mustache
@@ -1,3 +1 @@
-Uri.encodeComponent(
-  {{#includeLibraryTemplate}}api/query_param{{/includeLibraryTemplate}}.toString(),
-)
+Uri.encodeComponent({{#includeLibraryTemplate}}api/query_param{{/includeLibraryTemplate}}.toString())
\ No newline at end of file
diff --git a/modules/openapi-generator/src/main/resources/dart/libraries/dio/serialization/json_serializable/api/path_param.mustache b/modules/openapi-generator/src/main/resources/dart/libraries/dio/serialization/json_serializable/api/path_param.mustache
index 8241f8e9914d..1d633242d7cd 100644
--- a/modules/openapi-generator/src/main/resources/dart/libraries/dio/serialization/json_serializable/api/path_param.mustache
+++ b/modules/openapi-generator/src/main/resources/dart/libraries/dio/serialization/json_serializable/api/path_param.mustache
@@ -1,3 +1 @@
-Uri.encodeComponent(
-  {{#includeLibraryTemplate}}api/query_param{{/includeLibraryTemplate}}.toString(),
-)
+Uri.encodeComponent({{#includeLibraryTemplate}}api/query_param{{/includeLibraryTemplate}}.toString())
\ No newline at end of file
diff --git a/modules/openapi-generator/src/test/java/org/openapitools/codegen/dart/dio/DartDioClientCodegenTest.java b/modules/openapi-generator/src/test/java/org/openapitools/codegen/dart/dio/DartDioClientCodegenTest.java
index c4f74ec7014f..e501bb1d5c0d 100644
--- a/modules/openapi-generator/src/test/java/org/openapitools/codegen/dart/dio/DartDioClientCodegenTest.java
+++ b/modules/openapi-generator/src/test/java/org/openapitools/codegen/dart/dio/DartDioClientCodegenTest.java
@@ -474,7 +474,8 @@ public void testFreezedIgnoresUseOptional() throws IOException {
     /**
      * Path parameters must be URI-encoded as path components: the query_param helpers pass
      * strings through unchanged, so a value containing '/' or spaces would otherwise break
-     * the request path.
+     * the request path. Every path substitution must therefore go through
+     * Uri.encodeComponent.
      */
     @Test
     public void testPathParamsAreUriEncoded() throws IOException {
@@ -494,11 +495,20 @@ public void testPathParamsAreUriEncoded() throws IOException {
             List<File> files = generator.generate();
             files.forEach(File::deleteOnExit);
 
-            Path petApi = output.toPath().resolve("lib/src/api/pet_api.dart");
-            String content = Files.readString(petApi, StandardCharsets.UTF_8);
-            Assert.assertTrue(content.contains(".replaceAll("), content);
-            Assert.assertTrue(content.contains("Uri.encodeComponent("),
-                    "path parameter should be URI-encoded in " + serializationLibrary + ": " + content);
+            // check every generated api class, not just one
+            Path apiDir = output.toPath().resolve("lib/src/api");
+            try (var apiFiles = Files.list(apiDir)) {
+                for (Path apiFile : apiFiles.filter(p -> p.getFileName().toString().endsWith("_api.dart"))
+                        .collect(java.util.stream.Collectors.toList())) {
+                    String content = Files.readString(apiFile, StandardCharsets.UTF_8);
+                    int substitutions = content.split("\\.replaceAll\\(", -1).length - 1;
+                    Assert.assertTrue(substitutions > 0,
+                            "expected path substitutions in " + apiFile + ": " + content);
+                    int encodings = content.split("Uri\\.encodeComponent\\(", -1).length - 1;
+                    Assert.assertEquals(encodings, substitutions,
+                            "every path substitution in " + apiFile + " must be URI-encoded: " + content);
+                }
+            }
         }
     }
 
diff --git a/samples/openapi3/client/petstore/dart-dio/petstore-timemachine/lib/src/api/pet_api.dart b/samples/openapi3/client/petstore/dart-dio/petstore-timemachine/lib/src/api/pet_api.dart
index 8f6b3d378552..6161c2f7eb2d 100644
--- a/samples/openapi3/client/petstore/dart-dio/petstore-timemachine/lib/src/api/pet_api.dart
+++ b/samples/openapi3/client/petstore/dart-dio/petstore-timemachine/lib/src/api/pet_api.dart
@@ -146,10 +146,7 @@ class PetApi {
     ProgressCallback? onSendProgress,
     ProgressCallback? onReceiveProgress,
   }) async {
-    final _path = r'/pet/{petId}'.replaceAll('{' r'petId' '}', Uri.encodeComponent(
-  encodeQueryParameter(_serializers, petId, const FullType(int)).toString(),
-)
-,);
+    final _path = r'/pet/{petId}'.replaceAll('{' r'petId' '}', Uri.encodeComponent(encodeQueryParameter(_serializers, petId, const FullType(int)).toString()),);
     final _options = Options(
       method: r'DELETE',
       headers: <String, dynamic>{
@@ -373,10 +370,7 @@ class PetApi {
     ProgressCallback? onSendProgress,
     ProgressCallback? onReceiveProgress,
   }) async {
-    final _path = r'/pet/{petId}'.replaceAll('{' r'petId' '}', Uri.encodeComponent(
-  encodeQueryParameter(_serializers, petId, const FullType(int)).toString(),
-)
-,);
+    final _path = r'/pet/{petId}'.replaceAll('{' r'petId' '}', Uri.encodeComponent(encodeQueryParameter(_serializers, petId, const FullType(int)).toString()),);
     final _options = Options(
       method: r'GET',
       headers: <String, dynamic>{
@@ -564,10 +558,7 @@ class PetApi {
     ProgressCallback? onSendProgress,
     ProgressCallback? onReceiveProgress,
   }) async {
-    final _path = r'/pet/{petId}'.replaceAll('{' r'petId' '}', Uri.encodeComponent(
-  encodeQueryParameter(_serializers, petId, const FullType(int)).toString(),
-)
-,);
+    final _path = r'/pet/{petId}'.replaceAll('{' r'petId' '}', Uri.encodeComponent(encodeQueryParameter(_serializers, petId, const FullType(int)).toString()),);
     final _options = Options(
       method: r'POST',
       headers: <String, dynamic>{
@@ -645,10 +636,7 @@ class PetApi {
     ProgressCallback? onSendProgress,
     ProgressCallback? onReceiveProgress,
   }) async {
-    final _path = r'/pet/{petId}/uploadImage'.replaceAll('{' r'petId' '}', Uri.encodeComponent(
-  encodeQueryParameter(_serializers, petId, const FullType(int)).toString(),
-)
-,);
+    final _path = r'/pet/{petId}/uploadImage'.replaceAll('{' r'petId' '}', Uri.encodeComponent(encodeQueryParameter(_serializers, petId, const FullType(int)).toString()),);
     final _options = Options(
       method: r'POST',
       headers: <String, dynamic>{
diff --git a/samples/openapi3/client/petstore/dart-dio/petstore-timemachine/lib/src/api/store_api.dart b/samples/openapi3/client/petstore/dart-dio/petstore-timemachine/lib/src/api/store_api.dart
index ce3dff4b1aee..ebd11aef63e3 100644
--- a/samples/openapi3/client/petstore/dart-dio/petstore-timemachine/lib/src/api/store_api.dart
+++ b/samples/openapi3/client/petstore/dart-dio/petstore-timemachine/lib/src/api/store_api.dart
@@ -43,10 +43,7 @@ class StoreApi {
     ProgressCallback? onSendProgress,
     ProgressCallback? onReceiveProgress,
   }) async {
-    final _path = r'/store/order/{orderId}'.replaceAll('{' r'orderId' '}', Uri.encodeComponent(
-  encodeQueryParameter(_serializers, orderId, const FullType(String)).toString(),
-)
-,);
+    final _path = r'/store/order/{orderId}'.replaceAll('{' r'orderId' '}', Uri.encodeComponent(encodeQueryParameter(_serializers, orderId, const FullType(String)).toString()),);
     final _options = Options(
       method: r'DELETE',
       headers: <String, dynamic>{
@@ -173,10 +170,7 @@ class StoreApi {
     ProgressCallback? onSendProgress,
     ProgressCallback? onReceiveProgress,
   }) async {
-    final _path = r'/store/order/{orderId}'.replaceAll('{' r'orderId' '}', Uri.encodeComponent(
-  encodeQueryParameter(_serializers, orderId, const FullType(int)).toString(),
-)
-,);
+    final _path = r'/store/order/{orderId}'.replaceAll('{' r'orderId' '}', Uri.encodeComponent(encodeQueryParameter(_serializers, orderId, const FullType(int)).toString()),);
     final _options = Options(
       method: r'GET',
       headers: <String, dynamic>{
diff --git a/samples/openapi3/client/petstore/dart-dio/petstore-timemachine/lib/src/api/user_api.dart b/samples/openapi3/client/petstore/dart-dio/petstore-timemachine/lib/src/api/user_api.dart
index 68ee84324d50..7555893e7eb5 100644
--- a/samples/openapi3/client/petstore/dart-dio/petstore-timemachine/lib/src/api/user_api.dart
+++ b/samples/openapi3/client/petstore/dart-dio/petstore-timemachine/lib/src/api/user_api.dart
@@ -266,10 +266,7 @@ class UserApi {
     ProgressCallback? onSendProgress,
     ProgressCallback? onReceiveProgress,
   }) async {
-    final _path = r'/user/{username}'.replaceAll('{' r'username' '}', Uri.encodeComponent(
-  encodeQueryParameter(_serializers, username, const FullType(String)).toString(),
-)
-,);
+    final _path = r'/user/{username}'.replaceAll('{' r'username' '}', Uri.encodeComponent(encodeQueryParameter(_serializers, username, const FullType(String)).toString()),);
     final _options = Options(
       method: r'DELETE',
       headers: <String, dynamic>{
@@ -323,10 +320,7 @@ class UserApi {
     ProgressCallback? onSendProgress,
     ProgressCallback? onReceiveProgress,
   }) async {
-    final _path = r'/user/{username}'.replaceAll('{' r'username' '}', Uri.encodeComponent(
-  encodeQueryParameter(_serializers, username, const FullType(String)).toString(),
-)
-,);
+    final _path = r'/user/{username}'.replaceAll('{' r'username' '}', Uri.encodeComponent(encodeQueryParameter(_serializers, username, const FullType(String)).toString()),);
     final _options = Options(
       method: r'GET',
       headers: <String, dynamic>{
@@ -535,10 +529,7 @@ class UserApi {
     ProgressCallback? onSendProgress,
     ProgressCallback? onReceiveProgress,
   }) async {
-    final _path = r'/user/{username}'.replaceAll('{' r'username' '}', Uri.encodeComponent(
-  encodeQueryParameter(_serializers, username, const FullType(String)).toString(),
-)
-,);
+    final _path = r'/user/{username}'.replaceAll('{' r'username' '}', Uri.encodeComponent(encodeQueryParameter(_serializers, username, const FullType(String)).toString()),);
     final _options = Options(
       method: r'PUT',
       headers: <String, dynamic>{
diff --git a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-freezed/lib/src/api/pet_api.dart b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-freezed/lib/src/api/pet_api.dart
index ba954c9411e1..8c6df90231db 100644
--- a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-freezed/lib/src/api/pet_api.dart
+++ b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-freezed/lib/src/api/pet_api.dart
@@ -118,10 +118,7 @@ class PetApi {
     ProgressCallback? onSendProgress,
     ProgressCallback? onReceiveProgress,
   }) async {
-    final _path = r'/pet/{petId}'.replaceAll('{' r'petId' '}', Uri.encodeComponent(
-  petId.toString(),
-)
-,);
+    final _path = r'/pet/{petId}'.replaceAll('{' r'petId' '}', Uri.encodeComponent(petId.toString()),);
     final _options = Options(
       method: r'DELETE',
       headers: <String, dynamic>{
@@ -339,10 +336,7 @@ _responseData = rawData == null ? null : deserialize<Set<Pet>, Pet>(rawData, 'Se
     ProgressCallback? onSendProgress,
     ProgressCallback? onReceiveProgress,
   }) async {
-    final _path = r'/pet/{petId}'.replaceAll('{' r'petId' '}', Uri.encodeComponent(
-  petId.toString(),
-)
-,);
+    final _path = r'/pet/{petId}'.replaceAll('{' r'petId' '}', Uri.encodeComponent(petId.toString()),);
     final _options = Options(
       method: r'GET',
       headers: <String, dynamic>{
@@ -500,10 +494,7 @@ _responseData = rawData == null ? null : deserialize<Pet, Pet>(rawData, 'Pet', g
     ProgressCallback? onSendProgress,
     ProgressCallback? onReceiveProgress,
   }) async {
-    final _path = r'/pet/{petId}'.replaceAll('{' r'petId' '}', Uri.encodeComponent(
-  petId.toString(),
-)
-,);
+    final _path = r'/pet/{petId}'.replaceAll('{' r'petId' '}', Uri.encodeComponent(petId.toString()),);
     final _options = Options(
       method: r'POST',
       headers: <String, dynamic>{
@@ -581,10 +572,7 @@ _responseData = rawData == null ? null : deserialize<Pet, Pet>(rawData, 'Pet', g
     ProgressCallback? onSendProgress,
     ProgressCallback? onReceiveProgress,
   }) async {
-    final _path = r'/pet/{petId}/uploadImage'.replaceAll('{' r'petId' '}', Uri.encodeComponent(
-  petId.toString(),
-)
-,);
+    final _path = r'/pet/{petId}/uploadImage'.replaceAll('{' r'petId' '}', Uri.encodeComponent(petId.toString()),);
     final _options = Options(
       method: r'POST',
       headers: <String, dynamic>{
@@ -687,10 +675,7 @@ _responseData = rawData == null ? null : deserialize<ApiResponse, ApiResponse>(r
     ProgressCallback? onSendProgress,
     ProgressCallback? onReceiveProgress,
   }) async {
-    final _path = r'/fake/{petId}/uploadImageWithRequiredFile'.replaceAll('{' r'petId' '}', Uri.encodeComponent(
-  petId.toString(),
-)
-,);
+    final _path = r'/fake/{petId}/uploadImageWithRequiredFile'.replaceAll('{' r'petId' '}', Uri.encodeComponent(petId.toString()),);
     final _options = Options(
       method: r'POST',
       headers: <String, dynamic>{
diff --git a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-freezed/lib/src/api/store_api.dart b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-freezed/lib/src/api/store_api.dart
index aee10338f9a5..0b9117eeb2f8 100644
--- a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-freezed/lib/src/api/store_api.dart
+++ b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-freezed/lib/src/api/store_api.dart
@@ -40,10 +40,7 @@ class StoreApi {
     ProgressCallback? onSendProgress,
     ProgressCallback? onReceiveProgress,
   }) async {
-    final _path = r'/store/order/{order_id}'.replaceAll('{' r'order_id' '}', Uri.encodeComponent(
-  orderId.toString(),
-)
-,);
+    final _path = r'/store/order/{order_id}'.replaceAll('{' r'order_id' '}', Uri.encodeComponent(orderId.toString()),);
     final _options = Options(
       method: r'DELETE',
       headers: <String, dynamic>{
@@ -167,10 +164,7 @@ _responseData = rawData == null ? null : deserialize<Map<String, int>, int>(rawD
     ProgressCallback? onSendProgress,
     ProgressCallback? onReceiveProgress,
   }) async {
-    final _path = r'/store/order/{order_id}'.replaceAll('{' r'order_id' '}', Uri.encodeComponent(
-  orderId.toString(),
-)
-,);
+    final _path = r'/store/order/{order_id}'.replaceAll('{' r'order_id' '}', Uri.encodeComponent(orderId.toString()),);
     final _options = Options(
       method: r'GET',
       headers: <String, dynamic>{
diff --git a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-freezed/lib/src/api/user_api.dart b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-freezed/lib/src/api/user_api.dart
index 1053514435ca..0076a6f55775 100644
--- a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-freezed/lib/src/api/user_api.dart
+++ b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-freezed/lib/src/api/user_api.dart
@@ -250,10 +250,7 @@ class UserApi {
     ProgressCallback? onSendProgress,
     ProgressCallback? onReceiveProgress,
   }) async {
-    final _path = r'/user/{username}'.replaceAll('{' r'username' '}', Uri.encodeComponent(
-  username.toString(),
-)
-,);
+    final _path = r'/user/{username}'.replaceAll('{' r'username' '}', Uri.encodeComponent(username.toString()),);
     final _options = Options(
       method: r'DELETE',
       headers: <String, dynamic>{
@@ -300,10 +297,7 @@ class UserApi {
     ProgressCallback? onSendProgress,
     ProgressCallback? onReceiveProgress,
   }) async {
-    final _path = r'/user/{username}'.replaceAll('{' r'username' '}', Uri.encodeComponent(
-  username.toString(),
-)
-,);
+    final _path = r'/user/{username}'.replaceAll('{' r'username' '}', Uri.encodeComponent(username.toString()),);
     final _options = Options(
       method: r'GET',
       headers: <String, dynamic>{
@@ -502,10 +496,7 @@ _responseData = rawData == null ? null : deserialize<String, String>(rawData, 'S
     ProgressCallback? onSendProgress,
     ProgressCallback? onReceiveProgress,
   }) async {
-    final _path = r'/user/{username}'.replaceAll('{' r'username' '}', Uri.encodeComponent(
-  username.toString(),
-)
-,);
+    final _path = r'/user/{username}'.replaceAll('{' r'username' '}', Uri.encodeComponent(username.toString()),);
     final _options = Options(
       method: r'PUT',
       headers: <String, dynamic>{
diff --git a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/api/pet_api.dart b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/api/pet_api.dart
index d2f23f84ef7a..56b029ed8ca0 100644
--- a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/api/pet_api.dart
+++ b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/api/pet_api.dart
@@ -114,10 +114,7 @@ class PetApi {
     ProgressCallback? onSendProgress,
     ProgressCallback? onReceiveProgress,
   }) async {
-    final _path = r'/pet/{petId}'.replaceAll('{' r'petId' '}', Uri.encodeComponent(
-  petId.toString(),
-)
-,);
+    final _path = r'/pet/{petId}'.replaceAll('{' r'petId' '}', Uri.encodeComponent(petId.toString()),);
     final _options = Options(
       method: r'DELETE',
       headers: <String, dynamic>{
@@ -335,10 +332,7 @@ _responseData = rawData == null ? null : deserialize<Set<Pet>, Pet>(rawData, 'Se
     ProgressCallback? onSendProgress,
     ProgressCallback? onReceiveProgress,
   }) async {
-    final _path = r'/pet/{petId}'.replaceAll('{' r'petId' '}', Uri.encodeComponent(
-  petId.toString(),
-)
-,);
+    final _path = r'/pet/{petId}'.replaceAll('{' r'petId' '}', Uri.encodeComponent(petId.toString()),);
     final _options = Options(
       method: r'GET',
       headers: <String, dynamic>{
@@ -492,10 +486,7 @@ _responseData = rawData == null ? null : deserialize<Pet, Pet>(rawData, 'Pet', g
     ProgressCallback? onSendProgress,
     ProgressCallback? onReceiveProgress,
   }) async {
-    final _path = r'/pet/{petId}'.replaceAll('{' r'petId' '}', Uri.encodeComponent(
-  petId.toString(),
-)
-,);
+    final _path = r'/pet/{petId}'.replaceAll('{' r'petId' '}', Uri.encodeComponent(petId.toString()),);
     final _options = Options(
       method: r'POST',
       headers: <String, dynamic>{
@@ -573,10 +564,7 @@ _responseData = rawData == null ? null : deserialize<Pet, Pet>(rawData, 'Pet', g
     ProgressCallback? onSendProgress,
     ProgressCallback? onReceiveProgress,
   }) async {
-    final _path = r'/pet/{petId}/uploadImage'.replaceAll('{' r'petId' '}', Uri.encodeComponent(
-  petId.toString(),
-)
-,);
+    final _path = r'/pet/{petId}/uploadImage'.replaceAll('{' r'petId' '}', Uri.encodeComponent(petId.toString()),);
     final _options = Options(
       method: r'POST',
       headers: <String, dynamic>{
@@ -679,10 +667,7 @@ _responseData = rawData == null ? null : deserialize<ApiResponse, ApiResponse>(r
     ProgressCallback? onSendProgress,
     ProgressCallback? onReceiveProgress,
   }) async {
-    final _path = r'/fake/{petId}/uploadImageWithRequiredFile'.replaceAll('{' r'petId' '}', Uri.encodeComponent(
-  petId.toString(),
-)
-,);
+    final _path = r'/fake/{petId}/uploadImageWithRequiredFile'.replaceAll('{' r'petId' '}', Uri.encodeComponent(petId.toString()),);
     final _options = Options(
       method: r'POST',
       headers: <String, dynamic>{
diff --git a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/api/store_api.dart b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/api/store_api.dart
index b52b8b8dea2e..4ffc14056b5a 100644
--- a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/api/store_api.dart
+++ b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/api/store_api.dart
@@ -40,10 +40,7 @@ class StoreApi {
     ProgressCallback? onSendProgress,
     ProgressCallback? onReceiveProgress,
   }) async {
-    final _path = r'/store/order/{order_id}'.replaceAll('{' r'order_id' '}', Uri.encodeComponent(
-  orderId.toString(),
-)
-,);
+    final _path = r'/store/order/{order_id}'.replaceAll('{' r'order_id' '}', Uri.encodeComponent(orderId.toString()),);
     final _options = Options(
       method: r'DELETE',
       headers: <String, dynamic>{
@@ -167,10 +164,7 @@ _responseData = rawData == null ? null : deserialize<Map<String, int>, int>(rawD
     ProgressCallback? onSendProgress,
     ProgressCallback? onReceiveProgress,
   }) async {
-    final _path = r'/store/order/{order_id}'.replaceAll('{' r'order_id' '}', Uri.encodeComponent(
-  orderId.toString(),
-)
-,);
+    final _path = r'/store/order/{order_id}'.replaceAll('{' r'order_id' '}', Uri.encodeComponent(orderId.toString()),);
     final _options = Options(
       method: r'GET',
       headers: <String, dynamic>{
diff --git a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/api/user_api.dart b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/api/user_api.dart
index 5f5717b8f9b0..166786eed585 100644
--- a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/api/user_api.dart
+++ b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-json_serializable/lib/src/api/user_api.dart
@@ -238,10 +238,7 @@ class UserApi {
     ProgressCallback? onSendProgress,
     ProgressCallback? onReceiveProgress,
   }) async {
-    final _path = r'/user/{username}'.replaceAll('{' r'username' '}', Uri.encodeComponent(
-  username.toString(),
-)
-,);
+    final _path = r'/user/{username}'.replaceAll('{' r'username' '}', Uri.encodeComponent(username.toString()),);
     final _options = Options(
       method: r'DELETE',
       headers: <String, dynamic>{
@@ -288,10 +285,7 @@ class UserApi {
     ProgressCallback? onSendProgress,
     ProgressCallback? onReceiveProgress,
   }) async {
-    final _path = r'/user/{username}'.replaceAll('{' r'username' '}', Uri.encodeComponent(
-  username.toString(),
-)
-,);
+    final _path = r'/user/{username}'.replaceAll('{' r'username' '}', Uri.encodeComponent(username.toString()),);
     final _options = Options(
       method: r'GET',
       headers: <String, dynamic>{
@@ -490,10 +484,7 @@ _responseData = rawData == null ? null : deserialize<String, String>(rawData, 'S
     ProgressCallback? onSendProgress,
     ProgressCallback? onReceiveProgress,
   }) async {
-    final _path = r'/user/{username}'.replaceAll('{' r'username' '}', Uri.encodeComponent(
-  username.toString(),
-)
-,);
+    final _path = r'/user/{username}'.replaceAll('{' r'username' '}', Uri.encodeComponent(username.toString()),);
     final _options = Options(
       method: r'PUT',
       headers: <String, dynamic>{
diff --git a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake/lib/src/api/pet_api.dart b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake/lib/src/api/pet_api.dart
index a8c1527fa1ff..379f664abef8 100644
--- a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake/lib/src/api/pet_api.dart
+++ b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake/lib/src/api/pet_api.dart
@@ -118,10 +118,7 @@ class PetApi {
     ProgressCallback? onSendProgress,
     ProgressCallback? onReceiveProgress,
   }) async {
-    final _path = r'/pet/{petId}'.replaceAll('{' r'petId' '}', Uri.encodeComponent(
-  encodeQueryParameter(_serializers, petId, const FullType(int)).toString(),
-)
-,);
+    final _path = r'/pet/{petId}'.replaceAll('{' r'petId' '}', Uri.encodeComponent(encodeQueryParameter(_serializers, petId, const FullType(int)).toString()),);
     final _options = Options(
       method: r'DELETE',
       headers: <String, dynamic>{
@@ -345,10 +342,7 @@ class PetApi {
     ProgressCallback? onSendProgress,
     ProgressCallback? onReceiveProgress,
   }) async {
-    final _path = r'/pet/{petId}'.replaceAll('{' r'petId' '}', Uri.encodeComponent(
-  encodeQueryParameter(_serializers, petId, const FullType(int)).toString(),
-)
-,);
+    final _path = r'/pet/{petId}'.replaceAll('{' r'petId' '}', Uri.encodeComponent(encodeQueryParameter(_serializers, petId, const FullType(int)).toString()),);
     final _options = Options(
       method: r'GET',
       headers: <String, dynamic>{
@@ -506,10 +500,7 @@ class PetApi {
     ProgressCallback? onSendProgress,
     ProgressCallback? onReceiveProgress,
   }) async {
-    final _path = r'/pet/{petId}'.replaceAll('{' r'petId' '}', Uri.encodeComponent(
-  encodeQueryParameter(_serializers, petId, const FullType(int)).toString(),
-)
-,);
+    final _path = r'/pet/{petId}'.replaceAll('{' r'petId' '}', Uri.encodeComponent(encodeQueryParameter(_serializers, petId, const FullType(int)).toString()),);
     final _options = Options(
       method: r'POST',
       headers: <String, dynamic>{
@@ -587,10 +578,7 @@ class PetApi {
     ProgressCallback? onSendProgress,
     ProgressCallback? onReceiveProgress,
   }) async {
-    final _path = r'/pet/{petId}/uploadImage'.replaceAll('{' r'petId' '}', Uri.encodeComponent(
-  encodeQueryParameter(_serializers, petId, const FullType(int)).toString(),
-)
-,);
+    final _path = r'/pet/{petId}/uploadImage'.replaceAll('{' r'petId' '}', Uri.encodeComponent(encodeQueryParameter(_serializers, petId, const FullType(int)).toString()),);
     final _options = Options(
       method: r'POST',
       headers: <String, dynamic>{
@@ -696,10 +684,7 @@ class PetApi {
     ProgressCallback? onSendProgress,
     ProgressCallback? onReceiveProgress,
   }) async {
-    final _path = r'/fake/{petId}/uploadImageWithRequiredFile'.replaceAll('{' r'petId' '}', Uri.encodeComponent(
-  encodeQueryParameter(_serializers, petId, const FullType(int)).toString(),
-)
-,);
+    final _path = r'/fake/{petId}/uploadImageWithRequiredFile'.replaceAll('{' r'petId' '}', Uri.encodeComponent(encodeQueryParameter(_serializers, petId, const FullType(int)).toString()),);
     final _options = Options(
       method: r'POST',
       headers: <String, dynamic>{
diff --git a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake/lib/src/api/store_api.dart b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake/lib/src/api/store_api.dart
index 1a3e0765284e..3c3e6ccb8f8d 100644
--- a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake/lib/src/api/store_api.dart
+++ b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake/lib/src/api/store_api.dart
@@ -43,10 +43,7 @@ class StoreApi {
     ProgressCallback? onSendProgress,
     ProgressCallback? onReceiveProgress,
   }) async {
-    final _path = r'/store/order/{order_id}'.replaceAll('{' r'order_id' '}', Uri.encodeComponent(
-  encodeQueryParameter(_serializers, orderId, const FullType(String)).toString(),
-)
-,);
+    final _path = r'/store/order/{order_id}'.replaceAll('{' r'order_id' '}', Uri.encodeComponent(encodeQueryParameter(_serializers, orderId, const FullType(String)).toString()),);
     final _options = Options(
       method: r'DELETE',
       headers: <String, dynamic>{
@@ -173,10 +170,7 @@ class StoreApi {
     ProgressCallback? onSendProgress,
     ProgressCallback? onReceiveProgress,
   }) async {
-    final _path = r'/store/order/{order_id}'.replaceAll('{' r'order_id' '}', Uri.encodeComponent(
-  encodeQueryParameter(_serializers, orderId, const FullType(int)).toString(),
-)
-,);
+    final _path = r'/store/order/{order_id}'.replaceAll('{' r'order_id' '}', Uri.encodeComponent(encodeQueryParameter(_serializers, orderId, const FullType(int)).toString()),);
     final _options = Options(
       method: r'GET',
       headers: <String, dynamic>{
diff --git a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake/lib/src/api/user_api.dart b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake/lib/src/api/user_api.dart
index f9a4d0ca1615..f7b22e1a2bf2 100644
--- a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake/lib/src/api/user_api.dart
+++ b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake/lib/src/api/user_api.dart
@@ -244,10 +244,7 @@ class UserApi {
     ProgressCallback? onSendProgress,
     ProgressCallback? onReceiveProgress,
   }) async {
-    final _path = r'/user/{username}'.replaceAll('{' r'username' '}', Uri.encodeComponent(
-  encodeQueryParameter(_serializers, username, const FullType(String)).toString(),
-)
-,);
+    final _path = r'/user/{username}'.replaceAll('{' r'username' '}', Uri.encodeComponent(encodeQueryParameter(_serializers, username, const FullType(String)).toString()),);
     final _options = Options(
       method: r'DELETE',
       headers: <String, dynamic>{
@@ -294,10 +291,7 @@ class UserApi {
     ProgressCallback? onSendProgress,
     ProgressCallback? onReceiveProgress,
   }) async {
-    final _path = r'/user/{username}'.replaceAll('{' r'username' '}', Uri.encodeComponent(
-  encodeQueryParameter(_serializers, username, const FullType(String)).toString(),
-)
-,);
+    final _path = r'/user/{username}'.replaceAll('{' r'username' '}', Uri.encodeComponent(encodeQueryParameter(_serializers, username, const FullType(String)).toString()),);
     final _options = Options(
       method: r'GET',
       headers: <String, dynamic>{
@@ -499,10 +493,7 @@ class UserApi {
     ProgressCallback? onSendProgress,
     ProgressCallback? onReceiveProgress,
   }) async {
-    final _path = r'/user/{username}'.replaceAll('{' r'username' '}', Uri.encodeComponent(
-  encodeQueryParameter(_serializers, username, const FullType(String)).toString(),
-)
-,);
+    final _path = r'/user/{username}'.replaceAll('{' r'username' '}', Uri.encodeComponent(encodeQueryParameter(_serializers, username, const FullType(String)).toString()),);
     final _options = Options(
       method: r'PUT',
       headers: <String, dynamic>{

From 685e5df1c6596b2e2c1d0def1af816005cf0e437 Mon Sep 17 00:00:00 2001
From: Inf1mum <vadim.lazuk@mail.ru>
Date: Tue, 3 Nov 2026 23:52:15 +0300
Subject: [PATCH 5/5] [dart-dio] widen source_helper lower bound to 1.3.8

source_helper 1.3.9+ requires Dart 3.9, but the freezed variant
advertises sdk >=3.8.0 - 1.3.8 (source_gen >=3.1.0 <5.0.0, Dart
^3.7.0) keeps 3.8 users able to resolve while 3.9+ users still get
1.3.13.

Addresses review feedback in #25544.
---
 .../src/main/resources/dart/libraries/dio/pubspec.mustache  | 6 ++++--
 .../dart-dio/petstore_client_lib_fake-freezed/pubspec.yaml  | 6 ++++--
 2 files changed, 8 insertions(+), 4 deletions(-)

diff --git a/modules/openapi-generator/src/main/resources/dart/libraries/dio/pubspec.mustache b/modules/openapi-generator/src/main/resources/dart/libraries/dio/pubspec.mustache
index 0fd014044c8e..40a3771c4fec 100644
--- a/modules/openapi-generator/src/main/resources/dart/libraries/dio/pubspec.mustache
+++ b/modules/openapi-generator/src/main/resources/dart/libraries/dio/pubspec.mustache
@@ -57,7 +57,9 @@ dev_dependencies:
   # unlike the json_serializable variant, this one has no copy_with_extension_gen
   # whose source_gen constraint would hold source_helper back; source_helper 1.4.0
   # added extension members that clash with json_serializable 6.x's internal
-  # copies and break the build_runner build script, so hold it below 1.4.0
-  source_helper: '>=1.3.13 <1.4.0'
+  # copies and break the build_runner build script, so hold it below 1.4.0.
+  # 1.3.9+ requires Dart 3.9 while this variant advertises >=3.8.0, so keep the
+  # 1.3.8 lower bound resolvable for 3.8 users
+  source_helper: '>=1.3.8 <1.4.0'
 {{/useFreezed}}
   test: '^1.16.0'
diff --git a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-freezed/pubspec.yaml b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-freezed/pubspec.yaml
index 3615b34d416c..4d08924131e1 100644
--- a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-freezed/pubspec.yaml
+++ b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake-freezed/pubspec.yaml
@@ -19,6 +19,8 @@ dev_dependencies:
   # unlike the json_serializable variant, this one has no copy_with_extension_gen
   # whose source_gen constraint would hold source_helper back; source_helper 1.4.0
   # added extension members that clash with json_serializable 6.x's internal
-  # copies and break the build_runner build script, so hold it below 1.4.0
-  source_helper: '>=1.3.13 <1.4.0'
+  # copies and break the build_runner build script, so hold it below 1.4.0.
+  # 1.3.9+ requires Dart 3.9 while this variant advertises >=3.8.0, so keep the
+  # 1.3.8 lower bound resolvable for 3.8 users
+  source_helper: '>=1.3.8 <1.4.0'
   test: '^1.16.0'