[BUG][javascript-flowtyped] Flow check error (node.js)

Created by: zole40

Bug Report Checklist

• Have you provided a full/minimal spec to reproduce the issue?
• Have you validated the input using an OpenAPI validator (example)?
• Have you tested with the latest master to confirm the issue still exists?
• Have you searched for related issues/PRs?
• What's the actual output vs expected output?

Description

I found the following problem in the generated code when tried to run the flow check:

Cannot delete localVarUrlObj.search because undefined [1] is incompatible with null [2]. [incompatible-type]

     openapi/src/api.js
   
              localVarUrlObj.query = Object.assign({}, localVarUrlObj.query, localVarQueryParameter, options.query);
                 // fix override query string Detail: https://stackoverflow.com/a/7517673/1077943
 [1]              delete localVarUrlObj.search;
           localVarRequestOptions.headers = Object.assign({}, localVarHeaderParameter, options.headers);
      
                 return {

     /private/tmp/flow/flowlib_34e1ce2/node.js
 [2] 2191│     search: string | null,

openapi-generator version: 4.3.1

OpenAPI declaration file content or url

openapi: '3.0.3'
info:
  version: 0.1.0
  title: Test
servers:
  - url: /api
tags:
  - name: test
    description: |
paths:
  /dummy:
    get:
      summary:  Dummy endpoint.
      operationId: dummy
      tags:
        - simulation
      description: |
        Dummy endpoint.
      responses:
        '200':
          description: Success call
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/DummySuccess'
        default:
          description: Server error
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/DummyError'

components:
  schemas:
    DummySuccess:
      type: string
      example: ok
    DummyError:
      properties:
        errorMassage:
          type: string
          example: error

Generation Details

• generatorName = "javascript-flowtyped"

Steps to reproduce

• run generator javascript-flowtyped
• run flow check

Related issues/PRs

Suggest a fix

Change this line delete localVarUrlObj.search; to this localVarUrlObj.search = null; It could solve the flow issue. It is seen to be ok, but I did not test it all possibilities yet.