[typescript-nestjs-server] #22928 improve request parameter handling

[aryobenholzner]

addresses #22928

• remove incorrect inline enum import
• correctly handle required and nullable specs
• add additional tests by generating server for parameter-test-spec.yaml to correctly handle various parameter types

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---

Summary by cubic

Improves request parameter handling for the TypeScript NestJS server generator to fix #22928, adding default values, numeric parsing with optional pipes, header/cookie binding, and safer type/import generation.

• New Features

  • Header params use a custom @headers decorator that lowercases lookups and supports pipes; cookie params via generated @Cookies decorator. If you use cookie params, add cookie-parser and app.use(cookieParser()).
  • Apply schema default values to controller params with NestJS DefaultValuePipe.
  • Added a “parameters” sample and e2e tests using parameter-test-spec.yaml.

• Bug Fixes

  • Generate correct types for required, optional, and nullable params; normalize undefined default values; parse numeric params with ParseIntPipe/ParseFloatPipe and mark pipes optional for non-required/nullable params.
  • Bind exact spec names (including $) by using baseName in Param/Query/Headers/Cookies decorators.
  • Import handling: exclude inline union string literals and check each union member before importing to avoid bad enum/union imports; docs updated for tsVersion/rxjsVersion.

^{Written for commit 57ec23f. Summary will update on new commits.}

[cubic-dev-ai]

7 issues found across 38 files

Prompt for AI agents (all issues)

Check if these issues are valid — if so, understand the root cause of each and fix them.


<file name="modules/openapi-generator/src/main/resources/typescript-nestjs-server/controller.mustache">

<violation number="1" location="modules/openapi-generator/src/main/resources/typescript-nestjs-server/controller.mustache:3">
P2: Controller template imports `../cookies-decorator`, but there is no generator template/file for `cookies-decorator`, so generated code will fail to compile due to a missing module.</violation>

<violation number="2" location="modules/openapi-generator/src/main/resources/typescript-nestjs-server/controller.mustache:16">
P2: Header parameter extraction may fail because @Headers uses lowercased keys; using the original OpenAPI header casing ({{baseName}}) can return undefined for headers like 'X-Auth-Token'.</violation>
</file>

<file name="samples/server/petstore/typescript-nestjs-server/builds/default/controllers/PetApi.controller.ts">

<violation number="1" location="samples/server/petstore/typescript-nestjs-server/builds/default/controllers/PetApi.controller.ts:42">
P2: Form and file parameters are missing NestJS parameter decorators, so these values will be undefined at runtime and the API handlers receive no form/file data.</violation>

<violation number="2" location="samples/server/petstore/typescript-nestjs-server/builds/default/controllers/PetApi.controller.ts:47">
P2: Upload endpoint defines a `file` parameter but lacks `@UseInterceptors(FileInterceptor(...))` and `@UploadedFile()`; NestJS won’t extract multipart file data, so `file` will be undefined and the upload endpoint won’t work.</violation>
</file>

<file name="samples/server/petstore/typescript-nestjs-server/test/app.e2e-spec.ts">

<violation number="1" location="samples/server/petstore/typescript-nestjs-server/test/app.e2e-spec.ts:61">
P2: Missing return/await on the supertest request means this test can pass without running the async assertions.</violation>
</file>

<file name="samples/server/petstore/typescript-nestjs-server/builds/parameters/controllers/DefaultApi.controller.ts">

<violation number="1" location="samples/server/petstore/typescript-nestjs-server/builds/parameters/controllers/DefaultApi.controller.ts:11">
P2: Numeric query/header/cookie params are typed as number but will arrive as strings at runtime unless ParseIntPipe or global ValidationPipe transform is enabled, leading to type mismatch when DefaultApi expects numbers.</violation>
</file>

<file name="modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/TypeScriptNestjsServerCodegen.java">

<violation number="1" location="modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/TypeScriptNestjsServerCodegen.java:442">
P2: Union import parsing skips required model imports when the union starts with a primitive (e.g., "string | MyModel"), because it only checks needToImport on the first union part.</violation>
</file>

---

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[cubic-dev-ai]

P2: Upload endpoint defines a file parameter but lacks @UseInterceptors(FileInterceptor(...)) and @UploadedFile(); NestJS won’t extract multipart file data, so file will be undefined and the upload endpoint won’t work.

Prompt for AI agents

Check if this issue is valid — if so, understand the root cause and fix it. At samples/server/petstore/typescript-nestjs-server/builds/default/controllers/PetApi.controller.ts, line 47:

<comment>Upload endpoint defines a `file` parameter but lacks `@UseInterceptors(FileInterceptor(...))` and `@UploadedFile()`; NestJS won’t extract multipart file data, so `file` will be undefined and the upload endpoint won’t work.</comment>

<file context>
@@ -38,12 +39,12 @@ export class PetApiController {
 
   @Post('/pet/:petId/uploadImage')
-  uploadFile(@Param('petId') petId: number, additionalMetadata: string, file: Blob, @Req() request: Request): ApiResponse | Promise<ApiResponse> | Observable<ApiResponse> {
+  uploadFile(@Param('petId') petId: number, additionalMetadata: string | undefined, file: Blob | undefined, @Req() request: Request): ApiResponse | Promise<ApiResponse> | Observable<ApiResponse> {
     return this.petApi.uploadFile(petId, additionalMetadata, file, request);
   }
</file context>

[cubic-dev-ai]

P2: Form and file parameters are missing NestJS parameter decorators, so these values will be undefined at runtime and the API handlers receive no form/file data.

Prompt for AI agents

Check if this issue is valid — if so, understand the root cause and fix it. At samples/server/petstore/typescript-nestjs-server/builds/default/controllers/PetApi.controller.ts, line 42:

<comment>Form and file parameters are missing NestJS parameter decorators, so these values will be undefined at runtime and the API handlers receive no form/file data.</comment>

<file context>
@@ -38,12 +39,12 @@ export class PetApiController {
 
   @Post('/pet/:petId')
-  updatePetWithForm(@Param('petId') petId: number, name: string, status: string, @Req() request: Request): void | Promise<void> | Observable<void> {
+  updatePetWithForm(@Param('petId') petId: number, name: string | undefined, status: string | undefined, @Req() request: Request): void | Promise<void> | Observable<void> {
     return this.petApi.updatePetWithForm(petId, name, status, request);
   }
</file context>

[macjohnny]

thanks for the fixes

[cubic-dev-ai]

1 issue found across 5 files (changes from recent commits).

Prompt for AI agents (all issues)

Check if these issues are valid — if so, understand the root cause of each and fix them.


<file name="modules/openapi-generator/src/main/resources/typescript-nestjs-server/cookies-decorator.mustache">

<violation number="1" location="modules/openapi-generator/src/main/resources/typescript-nestjs-server/cookies-decorator.mustache:20">
P2: Signed cookies parsed by cookie-parser are moved to `request.signedCookies`, so this decorator will return `undefined` for signed cookie parameters in Express setups with a secret. Consider falling back to `signedCookies` when the cookie is not found in `cookies`.</violation>
</file>

_{Reply with feedback, questions, or to request a fix. Tag @cubic-dev-ai to re-run a review.}

[cubic-dev-ai]

2 issues found across 19 files (changes from recent commits).

Prompt for AI agents (all issues)

Check if these issues are valid — if so, understand the root cause of each and fix them. If appropriate, use sub-agents to investigate and fix each issue separately.


<file name="samples/server/petstore/typescript-nestjs-server/builds/default/decorators/headers-decorator.ts">

<violation number="1" location="samples/server/petstore/typescript-nestjs-server/builds/default/decorators/headers-decorator.ts:15">
P2: Header lookup is case-sensitive against request.headers, which are lowercased by Node. Mixed-case header names (e.g., 'X-Request-ID') will return undefined unless normalized.</violation>
</file>

<file name="modules/openapi-generator/src/main/resources/typescript-nestjs-server/paramPipe.mustache">

<violation number="1" location="modules/openapi-generator/src/main/resources/typescript-nestjs-server/paramPipe.mustache:1">
P2: Optional numeric parameters without defaults will be parsed by ParseIntPipe/ParseFloatPipe and throw BadRequest when omitted, effectively making them required.</violation>
</file>

_{Reply with feedback, questions, or to request a fix. Tag @cubic-dev-ai to re-run a review.}

[aryobenholzner]

addressed nearly all of the feedback. the multipart and file upload requests should probably be a separate issue/PR as its not related to the original issue.

[macjohnny]

should we update the generated readme to indicate some additional imports/middleware are needed? or what exactly are users supposed to configure to make proper use of these changes?

[macjohnny]

please fix the indentation here

[macjohnny]

Suggested change

	export const Headers = createParamDecorator((data: string, ctx: ExecutionContext) => {
	export const Headers = createParamDecorator((headerName: string, ctx: ExecutionContext) => {

[macjohnny]

Suggested change

	export const Cookies = createParamDecorator((data: string, ctx: ExecutionContext) => {
	export const Cookies = createParamDecorator((cookieName: string, ctx: ExecutionContext) => {