@hey-api/client-fetch: Error is unknown when using default

[mlankamp]

Description

The I use a non-200 response code, the Error object is created with a specific type. But if I use response code default the response is created as unknown

OpenAPI specification (optional)

openapi: 3.0.1
info:
  title: Testing
  version: v1
paths:
  '/specific/{id}':
    post:
      tags:
        - Testing
      operationId: SpecficError
      parameters:
        - name: id
          in: path
          required: true
          schema:
            type: string
            format: uuid
      responses:
        '204':
          description: No Content
        '500':
          description: Unexpected error
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ProblemDetails'
  '/default/{id}':
    post:
      tags:
        - Testing
      operationId: DefaultError
      parameters:
        - name: id
          in: path
          required: true
          schema:
            type: string
            format: uuid
      responses:
        '204':
          description: No Content
        default:
          description: Unexpected error
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ProblemDetails'

components:
  schemas:
    ProblemDetails:
      type: object
      properties:
        type:
          type: string
          nullable: true
        title:
          type: string
          nullable: true
        status:
          type: integer
          format: int32
          nullable: true
        detail:
          type: string
          nullable: true
        instance:
          type: string
          nullable: true
      additionalProperties: { }

Configuration

import { defineConfig } from '@hey-api/openapi-ts';

export default defineConfig({
  input: 'source/swagger.yaml',
  output: {
    path: 'output',
    format: false,
    lint: false
  } ,
  client: '@hey-api/client-fetch',
  schemas: false,
  types: {
    enums: 'javascript'
  },
  services: {
    asClass: true,
  }
});

System information (optional)

Example repo: https://github.com/mlankamp/openapi

[mlankamp]

I think the problem is caused by

openapi-ts/packages/openapi-ts/src/utils/write/types.ts

Line 403 in 032bd93

const errorResults = getErrorResponses(operation.errors);

The causes the error to be filtered twice, because the operation.errors is already assigned with operation.errors = getErrorResponses(operationResponses);

Changing line 403 to : const errorResults = operation.errors; fixes the problem.

[mrlubos]

cc @gergan

[gergan]

Yes I think @mlankamp is correct -> operation.errors are set in operation.ts and they are already filtered through getErrorResponses so no need to filter them once more. It seems that removing the function call is the correct thing to do. Albeit my question is if the logic for the default in

openapi-ts/packages/openapi-ts/src/openApi/common/parser/operation.ts

Line 139 in a9dfda0

export const inferDefaultResponse = (

is correct. If I understand the specification correctly https://github.com/OAI/OpenAPI-Specification/blob/main/versions/2.0.md#fixed-fields-9 or https://github.com/OAI/OpenAPI-Specification/blob/main/versions/3.1.0.md#fixed-fields-14 it seems that default covers all the responses, which are not declared. But inferDefaultResponse tries to identify if there are declared success responses and in this way decides if the default is only for error responses...

[sbking]

I'm running into this as well - unfortunately it causes issues with discriminating the data type:

const { data, error } = await foo();
if (error) throw error;
data; // TypeScript still thinks this is `Response | undefined` because it can't discriminate the type of `data` based on the `unknown` error type.

[mrlubos]

Sorry for the delay all, try with the next version once it's released