[typescript-angular] error TS1345: An expression of type 'void' cannot be tested for truthiness

[itsTeknas]

Description

The generated typescript client fails in angular 7 build when there seems to be any sort of file field.

Typescript version

"typescript": "^3.1.3"

Swagger-codegen version

The latest online version

Swagger declaration file content or url

parameters:
        - name: attachment1
          type: file
          in: formData
          required: false

Produces:

if (attachment1 !== undefined) {
            formParams = formParams.append('attachment1', <any>attachment1) || formParams;
}

The definition of append tracks down to

let formParams: { append(param: string, value: any): void; };

Steps to reproduce

Generate a new client with angular-typescript selected.

[artwel]

Same problem in our environment, after updating angular from v6 to v7 it is not possible to compile the genereated swagger services with the same error as seen above.
tried swagger-codegen-cli 2.4.0-SNAPSHOT and 3.0.2

[Dviejopomata]

Also happens with

import { Observable } from 'rxjs/Observable'

Which has to be :

import { Observable } from 'rxjs'

As a workaround you can use some bash after generating the code

sed -i 's/rxjs\/Observable/rxjs/' ./src/app/swagger/api/api.service.ts 
sed -i 's/formParams = formParams/formParams/' ./src/app/swagger/api/api.service.ts 
sed -i 's/ || formParams//' ./src/app/swagger/api/api.service.ts 

[itsTeknas]

@Dviejopomata yeah this has been the case after updating the rxjs version to 6.0.0

[itsTeknas]

@Dviejopomata , this actually has been implemented, you just need to pass the ngversion parameter while generating. The online generator is generating for angular 4.3 as a default.

[awalland]

@Dviejopomata , this actually has been implemented, you just need to pass the ngversion parameter while generating. The online generator is generating for angular 4.3 as a default.

do you have any pointers to what to set it? i tried with --additional-properties ngVersion=6.0.0 but that didn't seem to do anything.

[Dviejopomata]

@awalland Make sure you are using v3.0.0 at least, i had to change from v2.3.1 to v3.0.0 and it worked fine:

Since i'm using docker this is what my command looks like:

docker run --rm -v ${PWD}/src/app/swagger:/local swaggerapi/swagger-codegen-cli:unstable generate -i http://192.168.1.47:5070/swagger/v1/swagger.json -l typescript-angular -o /local --additional-properties ngVersion=6.0.0

[jkarun]

I'm facing same problem, after I updating angular from v5 to v7. I used all version of swagger cli jars. I used following command to generate swagger code

java -jar ./swagger-codegen-cli-3.0.0-20180710.190537-87.jar generate -i http:///swagger/v1/swagger.json -l typescript-angular -o ./local --additional-properties ngVersion=7.0.0

[TvrtkoM]

With swagger-codegen-cli-3.0.3.jar I get invalid petApi.service.ts

petApi.service.ts(364,1): error TS1005: '}' expected.

Used command is
java -jar ./swagger-codegen-cli-3.0.3.jar generate -i petstore.yaml -l typescript-angular -o ./local --additional-prop erties ngVersion=7.0.0

Same if I use ngVersion 7.1.0

Also all codegen-cli (jars) are generating invalid typescript 3 code. Errors are related to rxjs Imports and An expression of type 'void' cannot be tested for truthiness

Problematic code is

    let formParams: { append(param: string, value: any): void; };
    let useForm = false;
    let convertFormParamsToString = false;
    if (useForm) {
        formParams = new FormData();
    } else {
        formParams = new HttpParams({encoder: new CustomHttpUrlEncodingCodec()});
    }
    if (name !== undefined) {
        formParams = formParams.append('name', <any>name) || formParams;
    }
    if (status !== undefined) {
        formParams = formParams.append('status', <any>status) || formParams;
    }

useForm boolean is basically hardcoded and FormData constructor is never used.
formParams should be of this type and formParams=new FormData() line removed (i thinlk):
let formParams: { append(param: string, value: any): HttpParams; };

[plathub]

Proposed fix: change the line

let formParams: { append(param: string, value: any): void; };

to

let formParams: { append(param: string, value: any): void | HttpParams; };

in the template file api.service.mustache

[tilowestermann]

Is there any update on this issue (or the proposed PRs)?