multi-project/projects/app/_helpers/fake-backend.ts

77 lines
2.7 KiB
TypeScript

import { Injectable } from '@angular/core';
import { HttpRequest, HttpResponse, HttpHandler, HttpEvent, HttpInterceptor, HTTP_INTERCEPTORS } from '@angular/common/http';
import { Observable, of, throwError } from 'rxjs';
import { delay, mergeMap, materialize, dematerialize } from 'rxjs/operators';
const users = [{ id: 1, username: 'test', password: 'test', firstName: 'Test', lastName: 'User' }];
@Injectable()
export class FakeBackendInterceptor implements HttpInterceptor {
intercept(request: HttpRequest<any>, next: HttpHandler): Observable<HttpEvent<any>> {
const { url, method, headers, body } = request;
// wrap in delayed observable to simulate server api call
return of(null)
.pipe(mergeMap(handleRoute))
.pipe(materialize()) // call materialize and dematerialize to ensure delay even if an error is thrown (https://github.com/Reactive-Extensions/RxJS/issues/648)
.pipe(delay(500))
.pipe(dematerialize());
function handleRoute() {
switch (true) {
case url.endsWith('/users/authenticate') && method === 'POST':
return authenticate();
case url.endsWith('/users') && method === 'GET':
return getUsers();
default:
// pass through any requests not handled above
return next.handle(request);
}
}
// route functions
function authenticate() {
const { username, password } = body;
const user = users.find(x => x.username === username && x.password === password);
if (!user) return error('Username or password is incorrect');
return ok({
id: user.id,
username: user.username,
firstName: user.firstName,
lastName: user.lastName,
token: 'fake-jwt-token'
})
}
function getUsers() {
if (!isLoggedIn()) return unauthorized();
return ok(users);
}
// helper functions
function ok(body?) {
return of(new HttpResponse({ status: 200, body }))
}
function error(message) {
return throwError({ error: { message } });
}
function unauthorized() {
return throwError({ status: 401, error: { message: 'Unauthorised' } });
}
function isLoggedIn() {
return headers.get('Authorization') === 'Bearer fake-jwt-token';
}
}
}
export let fakeBackendProvider = {
// use fake backend in place of Http service for backend-less development
provide: HTTP_INTERCEPTORS,
useClass: FakeBackendInterceptor,
multi: true
};