[BUG][typescript-angular] PDF Response Type Treated As JSON

[oaklandcorp-jkaiser]

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?
• [Optional] Sponsorship to speed up the bug fix or feature request (example)

Description

A runtime exception occurs when invoking a service method using options
{httpHeaderAccept: 'application/pdf'} when that route supports multiple media
types because it appears to be treated as JSON in the generated service code.

openapi-generator version

<= 5.3.0

OpenAPI declaration file content or url

openapi: 3.0.0
info:
    version: '1.0'
    title: Document API
paths:
    /document:
        get:
            summary: Returns a document.
            responses:
                '200':
                    description: Found a document.
                    content:
                        text/plain:
                            schema:
                                type: string
                        application/pdf:
                            schema:
                                type: string
                                format: binary

Generation Details

openapi-generator generate -g typescript-angular -i example.yaml

Steps to reproduce

Generate a client using the provided OpenAPI spec and command. Invoke the
documentGet method of default.service.ts.

service.documentGet('body', false, {httpHeaderAccept: 'application/pdf'});

Related issues/PRs

None.

Suggest a fix

A minimal fix would be to expand the logic to decide the response type found in
the api.service.mustache template to include blob MIME types.

diff --git a/modules/openapi-generator/src/main/resources/typescript-angular/api.service.mustache b/modules/openapi-generator/src/main/resources/typescript-angular/api.service.mustache
index b7dd7cbd94b..f33a19132e4 100644
--- a/modules/openapi-generator/src/main/resources/typescript-angular/api.service.mustache
+++ b/modules/openapi-generator/src/main/resources/typescript-angular/api.service.mustache
@@ -349,9 +349,13 @@ export class {{classname}} {

 {{/hasFormParams}}
     {{^isResponseFile}}
-        let responseType_: 'text' | 'json' = 'json';
-        if(localVarHttpHeaderAcceptSelected && localVarHttpHeaderAcceptSelected.startsWith('text')) {
-            responseType_ = 'text';
+        let responseType_: 'text' | 'json' | 'blob' = 'json';
+        if (localVarHttpHeaderAcceptSelected) {
+            if (localVarHttpHeaderAcceptSelected.startsWith('text')) {
+                responseType_ = 'text';
+            } else if (!localVarHttpHeaderAcceptSelected.includes('json')) {
+                responseType_ = 'blob';
+            }
         }

     {{/isResponseFile}}