angular-cn/packages/http/testing/src/mock_backend.ts

265 lines
8.9 KiB
TypeScript

/**
* @license
* Copyright Google Inc. All Rights Reserved.
*
* Use of this source code is governed by an MIT-style license that can be
* found in the LICENSE file at https://angular.io/license
*/
import {Injectable} from '@angular/core';
import {Connection, ConnectionBackend, ReadyState, Request, Response} from '@angular/http';
import {ReplaySubject, Subject} from 'rxjs';
import {take} from 'rxjs/operators';
/**
*
* Mock Connection to represent a {@link Connection} for tests.
*
* @usageNotes
* ### Example of `mockRespond()`
*
* ```
* var connection;
* backend.connections.subscribe(c => connection = c);
* http.request('data.json').subscribe(res => console.log(res.text()));
* connection.mockRespond(new Response(new ResponseOptions({ body: 'fake response' }))); //logs
* 'fake response'
* ```
*
* ### Example of `mockError()`
*
* ```
* var connection;
* backend.connections.subscribe(c => connection = c);
* http.request('data.json').subscribe(res => res, err => console.log(err)));
* connection.mockError(new Error('error'));
* ```
*
* @deprecated see https://angular.io/guide/http
* @publicApi
*/
export class MockConnection implements Connection {
// TODO: Name `readyState` should change to be more generic, and states could be made to be more
// descriptive than ResourceLoader states.
/**
* Describes the state of the connection, based on `XMLHttpRequest.readyState`, but with
* additional states. For example, state 5 indicates an aborted connection.
*/
readyState: ReadyState;
/**
* {@link Request} instance used to create the connection.
*/
request: Request;
/**
* {@link EventEmitter} of {@link Response}. Can be subscribed to in order to be notified when a
* response is available.
*/
response: ReplaySubject<Response>;
constructor(req: Request) {
this.response = <any>new ReplaySubject(1).pipe(take(1));
this.readyState = ReadyState.Open;
this.request = req;
}
/**
* Sends a mock response to the connection. This response is the value that is emitted to the
* {@link EventEmitter} returned by {@link Http}.
*
*/
mockRespond(res: Response) {
if (this.readyState === ReadyState.Done || this.readyState === ReadyState.Cancelled) {
throw new Error('Connection has already been resolved');
}
this.readyState = ReadyState.Done;
this.response.next(res);
this.response.complete();
}
/**
* Not yet implemented!
*
* Sends the provided {@link Response} to the `downloadObserver` of the `Request`
* associated with this connection.
*/
mockDownload(res: Response) {
// this.request.downloadObserver.onNext(res);
// if (res.bytesLoaded === res.totalBytes) {
// this.request.downloadObserver.onCompleted();
// }
}
// TODO(jeffbcross): consider using Response type
/**
* Emits the provided error object as an error to the {@link Response} {@link EventEmitter}
* returned
* from {@link Http}.
*
*/
mockError(err?: Error) {
// Matches ResourceLoader semantics
this.readyState = ReadyState.Done;
this.response.error(err);
}
}
/**
* A mock backend for testing the {@link Http} service.
*
* This class can be injected in tests, and should be used to override providers
* to other backends, such as {@link XHRBackend}.
*
* @usageNotes
* ### Example
*
* ```
* import {Injectable, Injector} from '@angular/core';
* import {async, fakeAsync, tick} from '@angular/core/testing';
* import {BaseRequestOptions, ConnectionBackend, Http, RequestOptions} from '@angular/http';
* import {Response, ResponseOptions} from '@angular/http';
* import {MockBackend, MockConnection} from '@angular/http/testing';
*
* const HERO_ONE = 'HeroNrOne';
* const HERO_TWO = 'WillBeAlwaysTheSecond';
*
* @Injectable()
* class HeroService {
* constructor(private http: Http) {}
*
* getHeroes(): Promise<String[]> {
* return this.http.get('myservices.de/api/heroes')
* .toPromise()
* .then(response => response.json().data)
* .catch(e => this.handleError(e));
* }
*
* private handleError(error: any): Promise<any> {
* console.error('An error occurred', error);
* return Promise.reject(error.message || error);
* }
* }
*
* describe('MockBackend HeroService Example', () => {
* beforeEach(() => {
* this.injector = Injector.create([
* {provide: ConnectionBackend, useClass: MockBackend},
* {provide: RequestOptions, useClass: BaseRequestOptions},
* Http,
* HeroService,
* ]);
* this.heroService = this.injector.get(HeroService);
* this.backend = this.injector.get(ConnectionBackend) as MockBackend;
* this.backend.connections.subscribe((connection: any) => this.lastConnection = connection);
* });
*
* it('getHeroes() should query current service url', () => {
* this.heroService.getHeroes();
* expect(this.lastConnection).toBeDefined('no http service connection at all?');
* expect(this.lastConnection.request.url).toMatch(/api\/heroes$/, 'url invalid');
* });
*
* it('getHeroes() should return some heroes', fakeAsync(() => {
* let result: String[];
* this.heroService.getHeroes().then((heroes: String[]) => result = heroes);
* this.lastConnection.mockRespond(new Response(new ResponseOptions({
* body: JSON.stringify({data: [HERO_ONE, HERO_TWO]}),
* })));
* tick();
* expect(result.length).toEqual(2, 'should contain given amount of heroes');
* expect(result[0]).toEqual(HERO_ONE, ' HERO_ONE should be the first hero');
* expect(result[1]).toEqual(HERO_TWO, ' HERO_TWO should be the second hero');
* }));
*
* it('getHeroes() while server is down', fakeAsync(() => {
* let result: String[];
* let catchedError: any;
* this.heroService.getHeroes()
* .then((heroes: String[]) => result = heroes)
* .catch((error: any) => catchedError = error);
* this.lastConnection.mockError(new Response(new ResponseOptions({
* status: 404,
* statusText: 'URL not Found',
* })));
* tick();
* expect(result).toBeUndefined();
* expect(catchedError).toBeDefined();
* }));
* });
* ```
*
* @deprecated see https://angular.io/guide/http
* @publicApi
*/
@Injectable()
export class MockBackend implements ConnectionBackend {
/**
* {@link EventEmitter}
* of {@link MockConnection} instances that have been created by this backend. Can be subscribed
* to in order to respond to connections.
*
* This property only exists in the mock implementation, not in real Backends.
*/
connections: any; //<MockConnection>
/**
* An array representation of `connections`. This array will be updated with each connection that
* is created by this backend.
*
* This property only exists in the mock implementation, not in real Backends.
*/
connectionsArray: MockConnection[];
/**
* {@link EventEmitter} of {@link MockConnection} instances that haven't yet been resolved (i.e.
* with a `readyState`
* less than 4). Used internally to verify that no connections are pending via the
* `verifyNoPendingRequests` method.
*
* This property only exists in the mock implementation, not in real Backends.
*/
pendingConnections: any; // Subject<MockConnection>
constructor() {
this.connectionsArray = [];
this.connections = new Subject();
this.connections.subscribe(
(connection: MockConnection) => this.connectionsArray.push(connection));
this.pendingConnections = new Subject();
}
/**
* Checks all connections, and raises an exception if any connection has not received a response.
*
* This method only exists in the mock implementation, not in real Backends.
*/
verifyNoPendingRequests() {
let pending = 0;
this.pendingConnections.subscribe((c: MockConnection) => pending++);
if (pending > 0) throw new Error(`${pending} pending connections to be resolved`);
}
/**
* Can be used in conjunction with `verifyNoPendingRequests` to resolve any not-yet-resolve
* connections, if it's expected that there are connections that have not yet received a response.
*
* This method only exists in the mock implementation, not in real Backends.
*/
resolveAllConnections() { this.connections.subscribe((c: MockConnection) => c.readyState = 4); }
/**
* Creates a new {@link MockConnection}. This is equivalent to calling `new
* MockConnection()`, except that it also will emit the new `Connection` to the `connections`
* emitter of this `MockBackend` instance. This method will usually only be used by tests
* against the framework itself, not by end-users.
*/
createConnection(req: Request): MockConnection {
if (!req || !(req instanceof Request)) {
throw new Error(`createConnection requires an instance of Request, got ${req}`);
}
const connection = new MockConnection(req);
this.connections.next(connection);
return connection;
}
}