Setting up ngrx/data for integration testing

Question

I am trying to set up an integration test which will grab some data from a backend API service using ngrx/data entities.

I have this StackBlitz set up: https://stackblitz.com/edit/ngrxdata-testing-not-working-pxfmkb?file=src/main.ts

It should run tests on startup - there are no expectations in my test cases, however I am looking in the console logs and expecting it to show the log in ClientDataService (/src/app/data/client/client-data.service.ts), that is:

console.log('never goes here :(');

In the integration test (data.integration.spec.ts) I am configuring the module, defining the Client entity type and including the AppDataServiceModule which in turn does this:

import { NgModule } from '@angular/core';
import { ClientDataService } from './client/client-data.service';
import { EntityDataService, EntityDefinitionService } from '@ngrx/data';

@NgModule({
  providers: [
    ClientDataService,
  ],
})
export class AppDataServiceModule {
  constructor(
    entityDataService: EntityDataService,
    clientDataService: ClientDataService
  ) {
    entityDataService.registerService('Client', clientDataService);
  }
}

As you can see I am registering the data service as suggested by the ngrx docs, here

I feel like I am pretty close but just need a nudge in the right direction to get it working!

Answer 1

A custom DataService has to extend the DefaultDataService. Should look something like this:

export class ClientDataService extends DefaultDataService<Client> {

  constructor(
    http: HttpClient, httpUrlGenerator: HttpUrlGenerator
  ) {
    super('Client', http, httpUrlGenerator);
  }

  public getAll(): Observable<any> {
    // get Data here
  }
}

The BackendService has to return the Observable:

public getClients(): Observable<Array<Client>> {
  // will be mocked
  return of([
    {
      id: '1: Will not return as it will be mocked'
    },
    {
      id: '2: Will not return as it will be mocked'
    }
  ])
}

There are two more things which look suspicious to me:

1. There is no subscription in the code, so I assume your Observable is cold.
2. The clientResolve.resolve({}, {}) call expects an ActivatedRouteSnapshot as first parameter. I'm not so familiar with the Resolve interface but maybe thats an issue too.