Typescript union of number generates string enum in swagger

[tsimbalar]

Sorting

• I'm submitting a ...

  • bug report
  • feature request
  • support request

• I confirm that I

  • used the search to make sure that a similar issue hasn't already been submit

Expected Behavior

Given a type defined as

export interface MyAnswersRequest {
  readonly answers: {
    readonly answer1: AnswerValue;
  };
}

export type AnswerValue = 0 | 1 | 2 | 3;

I would expect it to generate OpenApi.yaml schemas such as :

        AnswerValue:
            type: number
            enum:
                - 0
                - 1
                - 2
                - 3
        MyAnswersRequest:
            properties:
                answers:
                    properties:
                        answer1:
                            $ref: '#/components/schemas/AnswerValue'
                    required:
                        - answer1
                    type: object
            required:
                - answers
            type: object
            additionalProperties: false

Current Behavior

Instead, the generated enum members are generated as strings (with single quotes)

        AnswerValue:
            type: number
            enum:
                - '0'
                - '1'
                - '2'
                - '3'

Our OpenApi linter (Spectral) complains (and it seems right) that even though the type of this enum is number , the listed acceptable values are strings

Note that this only seems to impact the generated swagger file, but validation of incoming requests work properly.

Possible Solution

Steps to Reproduce

Context (Environment)

Version of the library: "@tsoa/runtime": "3.9.0", / "@tsoa/cli": "3.9.0",
Version of NodeJS: v14.16.0

• Confirm you were using yarn not npm: [ ]

Detailed Description

Breaking change?

This might be a breaking change for people who rely on unions of number ... but this would only impact the generated swagger file, not the runtime behavior.

[WoH]

I suspect this may happen when we transform to yaml. Does a spec JSON have numbers?

[tsimbalar]

I just gave it a try by switching yaml to false in tsoa.json.

The generated swagger.json looks like this :

"AnswerValue": {
				"type": "number",
				"enum": [
					"0",
					"1",
					"2",
					"3"
				]
			},

so the enum members are generated as strings , not numbers in the JSON as well.

[tsimbalar]

I can confirm this is now fixed as of tsoa/cli v3.14.1
probably thanks to changes in :

• Fixed usage of correct types in enums #1117