Fix parameter uniqueness for form- and body-params (#7577)

If a form-parameter had the same name as another (header-, query-,
path-, or cookie-)parameter, a conflict could be caused (for example
in the typescript generator). This fix executes the same uniqueness-
check and renaming for form- and body-parameters as it is done for
all other parameters.

@see issue #7575

Co-authored-by: Alexander Rashed <alexander.rashed@ntsretail.com>

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

@@ -3856,10 +3856,20 @@ public class DefaultCodegen implements CodegenConfig {
         // add form/body parameter (if any) to the end of all parameter list
         if (!prependFormOrBodyParameters) {
             for (CodegenParameter cp : formParams) {
+                if (ensureUniqueParams) {
+                    if (!isParameterNameUnique(cp, allParams)) {
+                        cp.paramName = generateNextName(cp.paramName);
+                    }
+                }
                 allParams.add(cp.copy());
             }
 
             for (CodegenParameter cp : bodyParams) {
+                if (ensureUniqueParams) {
+                    if (!isParameterNameUnique(cp, allParams)) {
+                        cp.paramName = generateNextName(cp.paramName);
+                    }
+                }
                 allParams.add(cp.copy());
             }
         }

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

@@ -409,6 +409,20 @@ public class DefaultCodegenTest {
         Assert.assertTrue(queryParamsNames.contains("myparam2"));
     }
 
+    @Test
+    public void testUniquenessRenameOfFormParameters() throws Exception {
+        final OpenAPI openAPI = TestUtils.parseFlattenSpec("src/test/resources/3_0/form-duplicated-parameter.yaml");
+        DefaultCodegen codegen = new DefaultCodegen();
+        codegen.setOpenAPI(openAPI);
+        Operation operation = openAPI.getPaths().get("/form-param-poc/{id}").getPut();
+        CodegenOperation co = codegen.fromOperation("/form-param-poc/{id}", "put", operation, null);
+        Assert.assertEquals(co.path, "/form-param-poc/{id}");
+        Assert.assertEquals(co.allParams.size(), 2);
+        List<String> allParamsNames = co.allParams.stream().map(p -> p.paramName).collect(Collectors.toList());
+        Assert.assertTrue(allParamsNames.contains("id"));
+        Assert.assertTrue(allParamsNames.contains("id2"));
+    }
+
     @Test
     public void testGetSchemaTypeWithComposedSchemaWithOneOf() {
         final OpenAPI openAPI = TestUtils.parseFlattenSpec("src/test/resources/3_0/composed-oneof.yaml");

modules/openapi-generator/src/test/resources/3_0/form-duplicated-parameter.yaml

@@ -0,0 +1,50 @@
+openapi: 3.0.1
+info:
+  title: FormData Test Api Documentation
+  description: Minimal OpenAPI spec file to showcase duplicated params for formData.
+  version: 0.0.1
+servers:
+  - url: /backend/rest
+tags:
+  - name: form-param-poc
+    description: File storage resource for Fiscalization France standard
+paths:
+  '/form-param-poc/{id}':
+    put:
+      tags:
+        - form-param-poc
+      summary: fullUpdate
+      operationId: form-param-poc_update
+      parameters:
+        - name: id
+          in: path
+          required: true
+          schema:
+            type: integer
+            format: int64
+      requestBody:
+        content:
+          multipart/form-data:
+            schema:
+              $ref: '#/components/schemas/FormParameters'
+      responses:
+        '200':
+          description: OK.
+      security:
+        - oAuthConfig: []
+components:
+  schemas:
+    FormParameters:
+      type: object
+      properties:
+        id:
+          type: integer
+          format: int64
+          readOnly: true
+  securitySchemes:
+    oAuthConfig:
+      type: oauth2
+      flows:
+        implicit:
+          authorizationUrl: ../backend/login/openid
+          scopes: {}