How to avoid "ERROR: Spec method has no expectations" even when success?

Question

I have Angular HTTP service that makes some HTTP-calls. Here's an example of my service:

import { Injectable } from '@angular/core';
import { HttpClient } from '@angular/common/http';

@Injectable()
export class APIService {
    constructor(private readonly http: HttpClient) {}

    public async getUsers<T>(): Promise<T[]> {
        return await this.http.get<T[]>('/api/users').toPromise();
    }
}

And here's my spec.ts file for APIService:

import { TestBed } from '@angular/core/testing';
import { HttpClientTestingModule, HttpTestingController } from '@angular/common/http/testing';
import { APIService } from './api.service';

describe('API Service', () => {
    let service: APIService;
    let controller: HttpTestingController;

    beforeEach(() => {
        TestBed.configureTestingModule({
            imports: [HttpClientTestingModule],
            providers: [APIService]
        });

        service = TetsBed.get(APIService);
        controller = TestBed.get(HttpTestingController);
    });

    it('should create the API service', () => {
        expect(service).toBeTruthy();
    });

    it('should get users', () => {
        const expected = [{id: 1, email: 'email1@domain.tld'},
                          {id: 2, email: 'email2@domain.tld'}];

        service.getUsers<MyUserClass>().then((res) => {
            expect(res).toEqual(expected);
            controller.verify();
        });

        controller.expectOne('/api/users').flush(expected);
    });

});

Everything seems to works, cause when I run ng test, I have message like this:

ERROR: 'Spec 'API Service should get users' has no expectations.'
HeadlessChrome 77.0.3865 (Windows 10.0.0): Executed 13 of 15 SUCCESS (0 secs / 0.256 secs)
HeadlessChrome 77.0.3865 (Windows 10.0.0): Executed 15 of 15 SUCCESS (0.42 secs / 0.28 secs)
TOTAL: 15 SUCCESS
TOTAL: 15 SUCCESS
TOTAL: 15 SUCCESS

When I change something under next code, I got error.

.then((res) => {
    // expect(res).toEqual(expected);
    expect(res).toBeNull();
    controller.verify();
});

So code above is fine and working.

Then, why I have an error message with ERROR: 'Spec 'API Service should get users' has no expectations.'? Any ideas?

I guess, async/await might cause this problem, cause I don't actually wait for it, however, it executes with no error, and when I put wrong data, then it fails.

I also tried to wrap everything into async/fakeAsync methods - no luck.

Possible duplicate of [Spec has no expectations - Jasmine testing the callback function](https://stackoverflow.com/questions/45578981/spec-has-no-expectations-jasmine-testing-the-callback-function) — Vlad, Oct 08 '19 at 18:58

score 2 · Answer 1 · answered Oct 08 '19 at 18:56

Well, actually (done) solved my problem;

import { TestBed } from '@angular/core/testing';
import { HttpClientTestingModule, HttpTestingController } from '@angular/common/http/testing';
import { APIService } from './api.service';

describe('API Service', () => {
    let service: APIService;
    let controller: HttpTestingController;

    beforeEach(() => {
        TestBed.configureTestingModule({
            imports: [HttpClientTestingModule],
            providers: [APIService]
        });

        service = TetsBed.get(APIService);
        controller = TestBed.get(HttpTestingController);
    });

    it('should create the API service', () => {
        expect(service).toBeTruthy();
    });

    it('should get users', (done) => {
        const expected = [{id: 1, email: 'email1@domain.tld'},
                          {id: 2, email: 'email2@domain.tld'}];

        service.getUsers<MyUserClass>().then((res) => {
            expect(res).toEqual(expected);
            controller.verify();
            done();
        });

        controller.expectOne('/api/users').flush(expected);
    });

});

How to avoid "ERROR: Spec method has no expectations" even when success?

1 Answers1