[BUG][typescript-fetch] Schema with type array generates undefined function

[gk4m]

Bug Report Checklist

• Have you provided a full/minimal spec to reproduce the issue?
• Have you validated the input using an OpenAPI validator (example)?
• What's the version of OpenAPI Generator used?
• Have you search for related issues/PRs?
• What's the actual output vs expected output?
• [Optional] Bounty to sponsor the fix (example)

Description

I'm generating a typescript-fetch client using OpenAPI Generator 4.0.2. After running the generator, function stringToJSON is included in the output, but it is not defined.

openapi-generator version

4.0.2

OpenAPI declaration file content or url

{
  "swagger": "2.0",
  "info": {
    "description": "MyApi",
    "title": "MyApi",
    "version": "1.0.0"
  },
  "basePath": "/v1",
  "schemes": ["http"],
  "paths": {
    "/test": {
      "put": {
        "consumes": ["application/json"],
        "produces": ["application/json"],
        "parameters": [
          {
            "in": "body",
            "name": "body",
            "required": true,
            "schema": {
              "items": {
                "type": "string"
              },
              "type": "array"
            }
          }
        ],
        "responses": {
          "200": {
            "description": "OK"
          }
        }
      }
    }
  }
}

Command line used for generation

node_modules/.bin/openapi-generator generate -g typescript-fetch -i ./openapi.json -o ./src

Steps to reproduce

I've created a gist that should help to reproduce the issue.

git clone https://gist.github.com/gk4m/67045978063c7e2caf97fc8725620d62 bug-report
cd bug-report
yarn install
yarn generate
yarn test

You should see the following output:

src/apis/DefaultApi.ts:44:46 - error TS2304: Cannot find name 'stringToJSON'.

44             body: requestParameters.body.map(stringToJSON),

The source of the error can be found in src/apis/DefaultApi.ts which contains the following:

export interface TestPutRequest {
    body: Array<string>;
}

/**
 * no description
 */
export class DefaultApi extends runtime.BaseAPI {

    /**
     */
    async testPutRaw(requestParameters: TestPutRequest): Promise<runtime.ApiResponse<void>> {
        if (requestParameters.body === null || requestParameters.body === undefined) {
            throw new runtime.RequiredError('body','Required parameter requestParameters.body was null or undefined when calling testPut.');
        }

        const queryParameters: runtime.HTTPQuery = {};

        const headerParameters: runtime.HTTPHeaders = {};

        headerParameters['Content-Type'] = 'application/json';

        const response = await this.request({
            path: `/test`,
            method: 'PUT',
            headers: headerParameters,
            query: queryParameters,
            body: requestParameters.body.map(stringToJSON),
        });

        return new runtime.VoidApiResponse(response);
    }

    /**
     */
    async testPut(requestParameters: TestPutRequest): Promise<void> {
        await this.testPutRaw(requestParameters);
    }

}

Related issues/PRs

#1877

Suggest a fix

Function stringToJSON should be added to generated file.

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[macjohnny]

cc @TiFu

[macjohnny]

@gk4m would you like to give it a try and implement a fix? see also #2453

[dalinarkholin]

Sorry for the annoying bump, but any movement on this one? @wing328 @macjohnny

[macjohnny]

@dalinarkholin would you like to implement a fix for that? i can point you to the relevant files.

[macjohnny]

cc @Place1 @someone1

[dalinarkholin]

@macjohnny Was this included in 4.1.0? I still see the same behavior. stringToJSON function is undefined.

[macjohnny]

@dalinarkholin this should be inlcuded in 4.1.0
Can you post the relevant part of your spec?

[dalinarkholin]

@macjohnny my mistake. This is resolved.

[macjohnny]

thanks again to @someone1 for fixing this

[markspolakovs]

I'm still seeing this on 4.3.1. Here's a gist with a schema and the generated models/Listen.ts, invoked as npx @openapitools/openapi-generator-cli generate -i openapi.json -g typescript-fetch -o gen.

https://gist.github.com/markspolakovs/afd0bd3cdf6955a90fc1e75f60e166b1

[macjohnny]

@markspolakovs would you like to fix this issue?

[markocevar]

Any workaround possible for this issue?

[wing328]

@markspolakovs did you try the latest master or stable version v5.0.1?

What do the actual code and expected code look like?

[markspolakovs]

@wing328 Can still reproduce on v5.0.1, here's the input and output.

On line 40 the generator outputs syntactically invalid TypeScript ('boolean' only refers to a type, but is being used as a value here.). Will try master in a sec.

[ssalimit]

For me this happens when I use v5.0.0-beta3 onwards, but it looks fine when using v5.0.0-beta2. Is there any possible workaround?

[jacek-rzrz]

I'm seeing seemingly the same problem on v. 5.2.0 now:

JsonAPI spec:

...
"included" : {
  "type" : "array",
  "description" : "...",
  "items" : {
    "oneOf" : [ {
      "type" : "object"
    }, {
      "type" : "boolean"
    }, {
      "type" : "string"
    }, {
      "type" : "number"
    } ]
  }
}
...

Typescript type looks like that:

export interface V1BunnyBunnyId204409787 {
    included?: Array<object | boolean | string | number>;
}

And the generated fromJSON / toJSON functions are invalid:

return {
    'included': !exists(json, 'included') ? undefined : ((json['included'] as Array<any>).map(object | boolean | string | numberFromJSON)),
};

[simPod]

Has anyone found any workaround? 6.2.1 and I see a lot of undefined functions like stringToJSON etc.

[rohanrajpal]

Facing the same issue here, shall post a workaround tho if I find one

[Holt59]

Any update in 2023? How is anyone using this generator if a simple application/x-www-form-urlencoded completely breaks it...

[wing328]

If anyone would like to contribute a fix or sponsor a fix, please reply to let us know.