typescript-fetch generated code BaseAPI class doesn't compile

[CluEleSsUK]

Description

The generated BaseAPI has a non-nullable field Configuration, but it is conditionally assigned in the constructor, resulting in a TS2564 Property 'configuration' has no initializer and is not definitely assigned in the constructor.

Also, in the RequiredError below, the value name has the same issue. It seems to use a semicolon instead of an = symbol

Swagger-codegen version

2.3.1 using version 1.0.44 parser (due to the bundled parser not following refs correctly as has been detailed on another issue)

Swagger declaration file content or url

Any yaml produces it, but here's an abridged version for referenced
If you post the code inline, please wrap it with

swagger: "2.0"
info:
  description: API for VK
  version: "1.0.0"
  title: Blah
tags:
  - name: Miscellaneous
    description: A collection of endpoints for miscellaneous technical tasks

paths:


  '/actuator/health':
    get:
      tags:
        - Miscellaneous
      produces:
        - application/json
      responses:
        200:
          description: Service is health
        503:
          description: Service is unavailable

schemes:
  - http

Command line used for generation

maven plugin

Steps to reproduce

maven install, then try and use a typescript compiler or see the generated output

Related issues/PRs

Nope

Suggest a fix/enhancement

Within the following file: https://github.com/swagger-api/swagger-codegen/blob/master/modules/swagger-codegen/src/main/resources/typescript-fetch/api.mustache,

Either make configuration nullable , or provide a default one.
Change the colon to an equals in RequiredError.

[CluEleSsUK]

I have raised a PR with my suggested changes here:
#9460

[Fenopiu]

The problem is still there and even the brew one doesn't compile installing the swagger-codegen v 2.4.6.
It writes some very old Typescript style that is no more supported in TS >= 3 (probable even some TS2 version have the same problem because it is a JS approach more than a TS approach).
Example with the suggested Petstore API:

export class BaseAPI {
    protected configuration: Configuration;

    constructor(configuration?: Configuration, protected basePath: string = BASE_PATH, protected fetch: FetchAPI = portableFetch) {
        if (configuration) {
            this.configuration = configuration;
            this.basePath = configuration.basePath || this.basePath;
        }
    }
};

The configuration variable has not always an assignment in the constructor.

export class RequiredError extends Error {
    name: "RequiredError"
    constructor(public field: string, msg?: string) {
        super(msg);
    }
}

The name variable has clearly no instantiation nor assignment.

So the api.ts doesn't compile.

[CluEleSsUK]

Unfortunately, looking at the top contributors here, none of them seem to be committing this year :( I fear my PR to fix this will not get merged for a while (as it's sat there for a while already!). Any advice as to whom I could tag to get this merged?

[CluEleSsUK]

@mhardorf @leonyu do either of you guys have merge access? could you possibly take a look?

[akd-io]

I've run into this problem today. Anyone know anything about the status on this?
Do you remember how you solved it, @CluEleSsUK?

[CluEleSsUK]

Ended up using https://github.com/OpenAPITools/openapi-generator instead, but you could pull my fork and build locally to get it to work

[nathanstitt]

5.4.0 seems to correct this.

I'd been locked to 5.1.1 due to this bug, but just upgraded to 5.4.0 and was able to compile TS without errors.

[onlyanegg]

@nathanstitt , are you talking about openapi-generator? Or am I missing something. The latest swagger-codegen seems to be 3.0.34

https://github.com/swagger-api/swagger-codegen/releases/tag/v3.0.34