[BUG] [typescript-fetch] TS2339: Property 'map' does not exist on type 'Set '.

Hello,

The code generated by openapitools generator does not compile for my app.

openapi-generator version : 5.1.0

export function UserToJSON(value?: User | null): any {
    if (value === undefined) {
        return undefined;
    }
    if (value === null) {
        return null;
    }
    return {
        
        'id': value.id,
        'firstName': value.firstName,
        'lastName': value.lastName,
        'matricule': value.matricule,
        'civility': CivilityToJSON(value.civility),
=>        // This line generates the following error => TS2339: Property 'map' does not exist on type 'Set '.
        'roles': value.roles === undefined ? undefined : (Array.from((value.roles as Set<any>).map(RoleToJSON))),
    };
}

Steps to reproduce

npx @openapitools/openapi-generator-cli generate -i http://localhost:8082/v3/api-docs -g typescript-fetch -o ./src/lib/sdk --additional-properties=typescriptThreePlus --additional-properties=supportES6=true

tsconfig =>

  "compileOnSave": false,
  "compilerOptions": {
    "rootDir": ".",
    "sourceMap": true,
    "declaration": false,
    "moduleResolution": "node",
    "emitDecoratorMetadata": true,
    "experimentalDecorators": true,
    "importHelpers": true,
    "target": "es2015",
    "module": "esnext",
    "lib": [ "dom","es6",
      "dom.iterable",
      "esnext"],
    "skipLibCheck": true,
    "skipDefaultLibCheck": true,
    "baseUrl": ".",
    "paths": {
      "@hlpr-front/utils": ["libs/utils/src/index.ts"],
      "@hlpr-front/hlpr-api-sdk": ["libs/hlpr-api-sdk/src/index.ts"],
      "@hlpr-front/ui": ["libs/ui/src/index.ts"]
    },
    "jsx": "react",
    "forceConsistentCasingInFileNames": true
  },
  "exclude": ["node_modules", "tmp"]
}

OpenAPI model =>

"roles":{"uniqueItems":true,"type":"array","items":{"$ref":"#/components/schemas/Role"}}}}
... "Role":{"type":"object","properties":{"managementJob":...}

Any Help appreciated...

Start with the typescript-fetch generator output shown in the report, especially UserToJSON and the roles serialization expression. Reproduce the issue with the provided openapi-generator command and TypeScript configuration. Done means the generated TypeScript compiles for the uniqueItems array model without the TS2339 error.