Angular 5 service failing to pass unit tests with (NullInjectorError: No provider for...

I keep getting the following errors when running unit tests

Error: StaticInjectorError(DynamicTestModule)[ApiService -> HttpClient]:
StaticInjectorError(Platform: core)[ApiService -> HttpClient]:
NullInjectorError: No provider for HttpClient!


api.service.ts

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

@Injectable()
export class ApiService {

constructor(private http: HttpClient) { }
url = './assets/data.json';

get() {
return this.http.get(this.url);
}
}


api.service.spec.ts

import { TestBed, inject } from '@angular/core/testing';
import { HttpClientTestingModule, HttpTestingController } from '@angular/common/http/testing';

import { ApiService } from './api.service';

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

it('should get users', inject([HttpTestingController, ApiService],
(httpMock: HttpTestingController, apiService: ApiService) => {
expect(apiService).toBeTruthy();
}
)
);
});


I don't understand what is going wrong as I have included HttpClient into api.service.ts, the service works in the browser.

This is directly called in a component called MapComponent, and that is called inside HomeComponent.

Chrome 63.0.3239 (Mac OS X 10.13.3) HomeComponent expect opened to be false FAILED
Error: StaticInjectorError(DynamicTestModule)[ApiService -> HttpClient]:
StaticInjectorError(Platform: core)[ApiService -> HttpClient]:
NullInjectorError: No provider for HttpClient!

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