From 24291b196e57b67091091215c3b58504787b8b42 Mon Sep 17 00:00:00 2001
From: Kejia Liu <kejia@yaocheng.cn>
Date: Sat, 1 Aug 2026 13:52:20 +0800
Subject: [PATCH] fix(typescript-fetch): qualify anyToJSON for any-typed form
 parameters

A multipart/form-data parameter with no type at all ("any type") made the
generated apis/*.ts call a bare anyToJSON(...). The file only imports the
runtime as `* as runtime`, so that identifier does not exist and the output
does not compile (TS2304: Cannot find name 'anyToJSON').

    formParams.append('meta', new Blob([JSON.stringify(anyToJSON(...))], ...));

The free-form object case already uses runtime.anyToJSON; the any-type case
fell through to {{dataType}}ToJSON, and dataType is `any` for an any-typed
parameter, so it rendered as `anyToJSON`.

Add an isAnyType branch that uses runtime.anyToJSON as well.

Regenerating all 787 sample configs produces no diff.
---
 .../resources/typescript-fetch/apis.mustache  |  2 +-
 .../TypeScriptFetchClientCodegenTest.java     | 26 +++++++++++++++++++
 .../typescript-fetch/any-type-form-param.yaml | 23 ++++++++++++++++
 3 files changed, 50 insertions(+), 1 deletion(-)
 create mode 100644 modules/openapi-generator/src/test/resources/3_0/typescript-fetch/any-type-form-param.yaml

diff --git a/modules/openapi-generator/src/main/resources/typescript-fetch/apis.mustache b/modules/openapi-generator/src/main/resources/typescript-fetch/apis.mustache
index 97fb15df5253..bb507887b6da 100644
--- a/modules/openapi-generator/src/main/resources/typescript-fetch/apis.mustache
+++ b/modules/openapi-generator/src/main/resources/typescript-fetch/apis.mustache
@@ -285,7 +285,7 @@ export class {{classname}} extends runtime.BaseAPI {
             {{^isEnumRef}}
             {{^withoutRuntimeChecks}}
             {{^isContainer}}
-            formParams.append('{{baseName}}', new Blob([JSON.stringify({{#isFreeFormObject}}runtime.anyToJSON{{/isFreeFormObject}}{{^isFreeFormObject}}{{{dataType}}}ToJSON{{/isFreeFormObject}}(requestParameters['{{paramName}}']))], { type: "application/json", }));
+            formParams.append('{{baseName}}', new Blob([JSON.stringify({{#isFreeFormObject}}runtime.anyToJSON{{/isFreeFormObject}}{{^isFreeFormObject}}{{#isAnyType}}runtime.anyToJSON{{/isAnyType}}{{^isAnyType}}{{{dataType}}}ToJSON{{/isAnyType}}{{/isFreeFormObject}}(requestParameters['{{paramName}}']))], { type: "application/json", }));
             {{/isContainer}}
             {{#isContainer}}
             formParams.append('{{baseName}}', new Blob([JSON.stringify(requestParameters['{{paramName}}'])], { type: "application/json", }));
diff --git a/modules/openapi-generator/src/test/java/org/openapitools/codegen/typescript/fetch/TypeScriptFetchClientCodegenTest.java b/modules/openapi-generator/src/test/java/org/openapitools/codegen/typescript/fetch/TypeScriptFetchClientCodegenTest.java
index 0ba3cd8a5305..2aa5894e8c30 100644
--- a/modules/openapi-generator/src/test/java/org/openapitools/codegen/typescript/fetch/TypeScriptFetchClientCodegenTest.java
+++ b/modules/openapi-generator/src/test/java/org/openapitools/codegen/typescript/fetch/TypeScriptFetchClientCodegenTest.java
@@ -67,6 +67,32 @@ public void testOptionalResponseImports() {
         Assert.assertEquals(operation.isResponseOptional, true);
     }
 
+    @Test
+    public void testAnyTypeFormParamUsesQualifiedAnyToJSON() throws IOException {
+        // A form parameter with no type at all is "any type", not a free-form object. dataType is
+        // `any`, so `{{dataType}}ToJSON` renders as a bare `anyToJSON` -- but apis.ts only imports
+        // the runtime as `* as runtime`, so that identifier does not exist and the output does not
+        // compile. anyToJSON has to be referenced through the runtime namespace, the same way the
+        // free-form object case already does.
+        final String specPath = "src/test/resources/3_0/typescript-fetch/any-type-form-param.yaml";
+
+        File output = Files.createTempDirectory("test").toFile();
+        output.deleteOnExit();
+
+        final CodegenConfigurator configurator = new CodegenConfigurator()
+                .setGeneratorName("typescript-fetch")
+                .setInputSpec(specPath)
+                .setOutputDir(output.getAbsolutePath().replace("\\", "/"));
+
+        Generator generator = new DefaultGenerator();
+        List<File> files = generator.opts(configurator.toClientOptInput()).generate();
+        files.forEach(File::deleteOnExit);
+
+        Path api = Paths.get(output + "/apis/DefaultApi.ts");
+        TestUtils.assertFileContains(api, "runtime.anyToJSON(requestParameters['meta'])");
+        TestUtils.assertFileNotContains(api, "JSON.stringify(anyToJSON(");
+    }
+
     @Test
     public void testModelsWithoutPaths() throws IOException {
         final String specPath = "src/test/resources/3_1/reusable-components-without-paths.yaml";
diff --git a/modules/openapi-generator/src/test/resources/3_0/typescript-fetch/any-type-form-param.yaml b/modules/openapi-generator/src/test/resources/3_0/typescript-fetch/any-type-form-param.yaml
new file mode 100644
index 000000000000..ff36b49a5571
--- /dev/null
+++ b/modules/openapi-generator/src/test/resources/3_0/typescript-fetch/any-type-form-param.yaml
@@ -0,0 +1,23 @@
+openapi: 3.0.3
+info:
+  title: any-typed multipart form parameter
+  version: 1.0.0
+paths:
+  /upload:
+    post:
+      operationId: upload
+      requestBody:
+        content:
+          multipart/form-data:
+            schema:
+              type: object
+              properties:
+                file:
+                  type: string
+                  format: binary
+                # no type at all -> "any type", not a free-form object
+                meta:
+                  description: can be any type
+      responses:
+        "200":
+          description: ok