Load vendorExtensions in the operation parameter

docs/generators/java-camel.md

@@ -124,7 +124,7 @@ These options may be applied as additional-properties (cli) or configOptions (pl
 |x-operation-extra-annotation|List of custom annotations to be added to operation|OPERATION|null
 |x-spring-paginated|Add org.springframework.data.domain.Pageable to controller method. Can be used to handle page & size query parameters|OPERATION|false
 |x-version-param|Marker property that tells that this parameter would be used for endpoint versioning. Applicable for headers & query params. true/false|OPERATION_PARAMETER|null
-|x-pattern-message|Add this property whenever you need to customize the invalidation error message for the regex pattern of a variable|FIELD|null
+|x-pattern-message|Add this property whenever you need to customize the invalidation error message for the regex pattern of a variable|FIELD, OPERATION_PARAMETER|null
 
 
 ## IMPORT MAPPING

docs/generators/spring.md

@@ -117,7 +117,7 @@ These options may be applied as additional-properties (cli) or configOptions (pl
 |x-operation-extra-annotation|List of custom annotations to be added to operation|OPERATION|null
 |x-spring-paginated|Add org.springframework.data.domain.Pageable to controller method. Can be used to handle page & size query parameters|OPERATION|false
 |x-version-param|Marker property that tells that this parameter would be used for endpoint versioning. Applicable for headers & query params. true/false|OPERATION_PARAMETER|null
-|x-pattern-message|Add this property whenever you need to customize the invalidation error message for the regex pattern of a variable|FIELD|null
+|x-pattern-message|Add this property whenever you need to customize the invalidation error message for the regex pattern of a variable|FIELD, OPERATION_PARAMETER|null
 
 
 ## IMPORT MAPPING

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

@@ -5121,6 +5121,9 @@ public CodegenParameter fromParameter(Parameter parameter, Set<String> imports)
         if (parameter.getExtensions() != null && !parameter.getExtensions().isEmpty()) {
             codegenParameter.vendorExtensions.putAll(parameter.getExtensions());
         }
+        if (parameter.getSchema() != null && parameter.getSchema().getExtensions() != null && !parameter.getSchema().getExtensions().isEmpty()) {
+            codegenParameter.vendorExtensions.putAll(parameter.getSchema().getExtensions());
+        }
 
         Schema parameterSchema;
 

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

@@ -2,6 +2,7 @@
 
 import lombok.Getter;
 
+import java.util.Arrays;
 import java.util.Collections;
 import java.util.List;
 
@@ -21,7 +22,7 @@
     X_FIELD_EXTRA_ANNOTATION("x-field-extra-annotation", ExtensionLevel.FIELD, "List of custom annotations to be added to property", null),
     X_OPERATION_EXTRA_ANNOTATION("x-operation-extra-annotation", ExtensionLevel.OPERATION, "List of custom annotations to be added to operation", null),
     X_VERSION_PARAM("x-version-param", ExtensionLevel.OPERATION_PARAMETER, "Marker property that tells that this parameter would be used for endpoint versioning. Applicable for headers & query params. true/false", null),
-    X_PATTERN_MESSAGE("x-pattern-message", ExtensionLevel.FIELD, "Add this property whenever you need to customize the invalidation error message for the regex pattern of a variable", null),
+    X_PATTERN_MESSAGE("x-pattern-message", Arrays.asList(ExtensionLevel.FIELD, ExtensionLevel.OPERATION_PARAMETER), "Add this property whenever you need to customize the invalidation error message for the regex pattern of a variable", null),
     ;
 
     private final String name;

modules/openapi-generator/src/test/java/org/openapitools/codegen/java/spring/SpringCodegenTest.java

@@ -3148,6 +3148,61 @@ public void testXPatternMessage_issue5857() throws IOException {
                 ));
     }
 
+    @Test
+    public void testXPatternMessage_issue18959() throws IOException {
+        File output = Files.createTempDirectory("test").toFile().getCanonicalFile();
+        output.deleteOnExit();
+
+        final OpenAPI openAPI = TestUtils.parseFlattenSpec("src/test/resources/3_0/issue_18959.yaml");
+        final SpringCodegen codegen = new SpringCodegen();
+        codegen.setOpenAPI(openAPI);
+        codegen.setOutputDir(output.getAbsolutePath());
+
+        codegen.additionalProperties().put(SpringCodegen.DATE_LIBRARY, "java8-localdatetime");
+        codegen.additionalProperties().put(INTERFACE_ONLY, "true");
+        codegen.additionalProperties().put(USE_RESPONSE_ENTITY, "false");
+        codegen.additionalProperties().put(DELEGATE_PATTERN, "true");
+        codegen.additionalProperties().put(USE_BEANVALIDATION, "true");
+        codegen.additionalProperties().put(PERFORM_BEANVALIDATION, "true");
+        codegen.additionalProperties().put(REQUEST_MAPPING_OPTION, "api_interface");
+
+        ClientOptInput input = new ClientOptInput();
+        input.openAPI(openAPI);
+        input.config(codegen);
+
+        DefaultGenerator generator = new DefaultGenerator();
+        generator.setGenerateMetadata(false); // skip metadata generation
+
+        Map<String, File> files = generator.opts(input).generate().stream()
+                .collect(Collectors.toMap(File::getName, Function.identity()));
+
+        JavaFileAssert javaFileAssert = JavaFileAssert.assertThat(files.get("TestApi.java"));
+        javaFileAssert
+                .assertMethod("_postToTest")
+                .assertParameter("groupObj")
+                .assertParameterAnnotations()
+                .containsWithNameAndAttributes("Pattern", ImmutableMap.of(
+                        "regexp", "\"[a-zA-Z]\"",
+                        "message", "\"Only letters\""
+                ))
+                .toParameter()
+                .toMethod()
+                .assertParameter("token")
+                .assertParameterAnnotations()
+                .containsWithNameAndAttributes("Pattern", ImmutableMap.of(
+                        "regexp", "\"[0-9a-fA-F]\"",
+                        "message", "\"Only numbers and letters a-f\""
+                ))
+                .toParameter()
+                .toMethod()
+                .assertParameter("clientId")
+                .assertParameterAnnotations()
+                .containsWithNameAndAttributes("Pattern", ImmutableMap.of(
+                        "regexp", "\"\\\\d\"",
+                        "message", "\"Only numbers\""
+                ));
+    }
+
     @Test
     public void testEnumCaseInsensitive_issue8084() throws IOException {
         File output = Files.createTempDirectory("test").toFile().getCanonicalFile();

modules/openapi-generator/src/test/resources/3_0/issue_18959.yaml

@@ -0,0 +1,63 @@
+openapi: 3.0.3
+info:
+  title: sample spec
+  version: 1.0.0
+paths:
+  /test/{groupObj}:
+    post:
+      summary: Post to test
+      description: ''
+      operationId: postToTest
+      parameters:
+        - $ref: '#/components/parameters/groupObj'
+        - $ref: '#/components/parameters/token'
+        - $ref: '#/components/parameters/clientId'
+      requestBody:
+        content:
+          application/json:
+            schema:
+              $ref: '#/components/schemas/ObjTest'
+      responses:
+        201:
+          description: success
+components:
+  parameters:
+    groupObj:
+      in: path
+      name: groupObj
+      required: true
+      schema:
+        type: string
+        pattern: "[a-zA-Z]"
+        x-pattern-message: "Only letters"
+    token:
+      in: query
+      name: token
+      required: true
+      schema:
+        type: string
+        pattern: "[0-9a-fA-F]"
+        x-pattern-message: "Only numbers and letters a-f"
+    clientId:
+      in: header
+      name: clientId
+      required: true
+      schema:
+        type: string
+        pattern: "\\d"
+        x-pattern-message: "Only numbers"
+  schemas:
+    ObjTest:
+      description: A model to return
+      type: object
+      properties:
+        field1:
+          type: integer
+          format: int64
+        field2:
+          type: string
+          pattern: "\\w"
+          x-pattern-message: "Only letters, numbers and underscore"
+        field3:
+          type: string
+          pattern: "\\w"