[typescript-nestjs-server] #22928 improve request parameter handling by aryobenholzner · Pull Request #22960 · OpenAPITools/openapi-generator

aryobenholzner · 2026-02-12T22:38:00Z

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 in the TypeScript NestJS server generator to fix #22928. Adds schema defaults, numeric parsing with pipes, header/cookie decorators, strict null/undefined typing, and safer imports.

New Features
- Custom @Headers decorator (lowercase lookups + pipe support) and generated @Cookies decorator.
- Apply schema defaults with DefaultValuePipe; add param sample + e2e tests from parameter-test-spec.yaml.
- Generated API method/request-param types include null and undefined as per spec.
- Docs: Express-only note, cookie setup using cookie-parser, and ApiModule.forRoot({ apiImplementations, providers? }).
Bug Fixes
- Correct types for required/optional/nullable params; normalize "undefined" defaults.
- Parse numeric params with ParseIntPipe/ParseFloatPipe; pipes marked optional for non-required/nullable values.
- Bind exact spec names via baseName in Param/Query/Headers/Cookies (supports $, dashes, etc.).
- Import handling: skip inline union string literals and validate each union member before importing; clarified tsVersion/rxjsVersion docs.

^{Written for commit 387123d. Summary will update on new commits.}

…rings from generating imports

… various parameter types

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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modules/openapi-generator/src/main/resources/typescript-nestjs-server/controller.mustache

cubic-dev-ai · 2026-02-12T22:45:04Z

...les/server/petstore/typescript-nestjs-server/builds/default/controllers/PetApi.controller.ts


  @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> {


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 · 2026-02-12T22:45:04Z

...les/server/petstore/typescript-nestjs-server/builds/default/controllers/PetApi.controller.ts

@@ -1,5 +1,6 @@
-import { Body, Controller, Delete, Get, Post, Put, Param, Query, Req } from '@nestjs/common';
+import { Body, Controller, Delete, Get, Post, Put, Param, Query, Headers, Req } from '@nestjs/common';


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>

samples/server/petstore/typescript-nestjs-server/test/app.e2e-spec.ts

...ver/petstore/typescript-nestjs-server/builds/parameters/controllers/DefaultApi.controller.ts

...enerator/src/main/java/org/openapitools/codegen/languages/TypeScriptNestjsServerCodegen.java

macjohnny

thanks for the fixes

...enerator/src/main/java/org/openapitools/codegen/languages/TypeScriptNestjsServerCodegen.java

...les/openapi-generator/src/main/resources/typescript-nestjs-server/cookies-decorator.mustache

…ons and test execution

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.}

...les/openapi-generator/src/main/resources/typescript-nestjs-server/cookies-decorator.mustache

… parameters, use DefaultValuePipe for default values

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.}

samples/server/petstore/typescript-nestjs-server/builds/default/decorators/headers-decorator.ts

modules/openapi-generator/src/main/resources/typescript-nestjs-server/paramPipe.mustache

…, check each import for unions

…rs for number parse pipes

aryobenholzner · 2026-02-13T23:59:07Z

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?

...les/openapi-generator/src/main/resources/typescript-nestjs-server/headers-decorator.mustache

...les/openapi-generator/src/main/resources/typescript-nestjs-server/cookies-decorator.mustache

…nal PR feedback

aryobenholzner · 2026-02-18T18:28:51Z

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?

I updated the README, I also updated the usage description to reflect the changes from #22403

macjohnny · 2026-02-23T11:47:37Z

modules/openapi-generator/src/main/resources/typescript-nestjs-server/README.md


 Usage: The generated output is intended to be its own module, that can be imported into your NestJS App Module. You do not need to change generated files, just import the module and implement the API

+Currently, only Express is supported.


was this already the case before this change?

Fastify compability should not be any better or worse with this PR. Although some basic stuff might already work, I have never tested Fastify support.
The controllers currently forward the Request typed from express and from what I know Fastify has some specifics that might need different handling. That’s why I wanted to add the disclaimer until a generator option for Fastify exists where we can handle specifics, and have a test suite ensuring Fastify works properly.

modules/openapi-generator/src/main/resources/typescript-nestjs-server/README.md

…ter-handling # Conflicts: # samples/server/petstore/typescript-nestjs-server/package-lock.json # samples/server/petstore/typescript-nestjs-server/package.json

macjohnny

thanks for your contribution!

…er handling (OpenAPITools#22960) * [typescript-nestjs-server] OpenAPITools#22928 exclude inline union strings from generating imports * [typescript-nestjs-server] OpenAPITools#22928 add optional type hints * [typescript-nestjs-server] OpenAPITools#22928 add/improve support for various parameter types * [typescript-nestjs-server] OpenAPITools#22928 add docs, fix indentations and test execution * [typescript-nestjs-server] OpenAPITools#22928 correctly parse numeric parameters, use DefaultValuePipe for default values * [typescript-nestjs-server] OpenAPITools#22928 lowercase header access, check each import for unions * [typescript-nestjs-server] OpenAPITools#22928 allow optional parameters for number parse pipes * [typescript-nestjs-server] OpenAPITools#22928 updated README, additional PR feedback * [typescript-nestjs-server] OpenAPITools#22928 updated README

aryobenholzner added 3 commits February 12, 2026 23:20

[typescript-nestjs-server] OpenAPITools#22928 exclude inline union st…

39b0eaf

…rings from generating imports

[typescript-nestjs-server] OpenAPITools#22928 add optional type hints

1fae8c2

[typescript-nestjs-server] OpenAPITools#22928 add/improve support for…

617a8f6

… various parameter types

cubic-dev-ai bot reviewed Feb 12, 2026

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macjohnny requested changes Feb 13, 2026

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[typescript-nestjs-server] OpenAPITools#22928 add docs, fix indentati…

cd3b9a1

…ons and test execution

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...les/openapi-generator/src/main/resources/typescript-nestjs-server/cookies-decorator.mustache Outdated Show resolved Hide resolved

[typescript-nestjs-server] OpenAPITools#22928 correctly parse numeric…

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… parameters, use DefaultValuePipe for default values

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aryobenholzner added 2 commits February 14, 2026 00:14

[typescript-nestjs-server] OpenAPITools#22928 lowercase header access…

bb85c06

…, check each import for unions

[typescript-nestjs-server] OpenAPITools#22928 allow optional paramete…

57ec23f

…rs for number parse pipes

aryobenholzner requested a review from macjohnny February 13, 2026 23:59

macjohnny reviewed Feb 16, 2026

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aryobenholzner and others added 2 commits February 18, 2026 18:52

Merge branch 'OpenAPITools:master' into bugfix/22928-parameter-handling

702fa69

[typescript-nestjs-server] OpenAPITools#22928 updated README, additio…

0f46899

…nal PR feedback

aryobenholzner requested a review from macjohnny February 18, 2026 18:34

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aryobenholzner added 2 commits March 8, 2026 08:10

Merge remote-tracking branch 'origin/master' into bugfix/22928-parame…

b6d0a1a

…ter-handling # Conflicts: # samples/server/petstore/typescript-nestjs-server/package-lock.json # samples/server/petstore/typescript-nestjs-server/package.json

[typescript-nestjs-server] OpenAPITools#22928 updated README

387123d

aryobenholzner requested a review from macjohnny March 8, 2026 08:19

macjohnny approved these changes Mar 11, 2026

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macjohnny merged commit eaa79e2 into OpenAPITools:master Mar 11, 2026
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aryobenholzner deleted the bugfix/22928-parameter-handling branch March 12, 2026 15:56

		@@ -1,5 +1,6 @@
		import { Body, Controller, Delete, Get, Post, Put, Param, Query, Req } from '@nestjs/common';
		import { Body, Controller, Delete, Get, Post, Put, Param, Query, Headers, Req } from '@nestjs/common';


		Usage: The generated output is intended to be its own module, that can be imported into your NestJS App Module. You do not need to change generated files, just import the module and implement the API

		Currently, only Express is supported.

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