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• The commit message follows our guidelines: https://github.com/nestjs/nest/blob/master/CONTRIBUTING.md
• Tests for the changes have been added (for bug fixes / features)
• Docs have been added / updated (for bug fixes / features)

PR Type

What kind of change does this PR introduce?

• Bugfix
• Feature
• Code style update (formatting, local variables)
• Refactoring (no functional changes, no api changes)
• Build related changes
• CI related changes
• Other... Please describe:

What is the current behavior?

If you try to use the @ApiExtension() decorator at the controller level it has no effect on the OpenAPI file. It only has an effect on methods.

So using it at the controller level like this would have no effect on the create operation.

@ApiExtension('x-entitlements', ['api-access'])
@Controller('cats')
export class CatsController {
  constructor(private readonly catsService: CatsService) {}

  @Post()
  @ApiOperation({ summary: 'Create cat' })
  async create(@Body() createCatDto: CreateCatDto): Promise<Cat> {
    // ...
  }
}

Issue Number: N/A

What is the new behavior?

Now when @ApiParam() decorator is used on a controller the extension property is added to all the operations implemented by the controller.

The above example would apply the extension to the operation:

    "/api/cats": {
      "post": {
        "operationId": "CatsController_create",
// ...
        "summary": "Create cat",
        "tags": [
          "cats",
          "create cats"
        ],
        "x-entitlements": [
          "api-access"
        ]
      },

If you apply the same extension decorator at the method level it will override the controller level value. I spent a little time trying to merge the values but it added quite a bit of complexity and seemed like It could give some surprising results.

Does this PR introduce a breaking change?

• Yes
• No

Other information