fix(express-engine): set APP_BASE_HREF to req.baseUrl (#1252)

This avoids Angular route match failures when the Express engine is
mounted on a different URL (this happens e.g. with Firebase and other
serverless setups).

Author: vikerman

integration/express-engine-ivy/server.ts

@@ -5,6 +5,7 @@ import * as express from 'express';
 import { join } from 'path';
 
 import { AppServerModule } from './src/main.server';
+import { APP_BASE_HREF } from '@angular/common';
 
 // The Express app is exported so that it can be used by serverless Functions.
 export function app() {
@@ -28,7 +29,7 @@ export function app() {
 
   // All regular routes use the Universal engine
   server.get('*', (req, res) => {
-    res.render('index', { req });
+    res.render('index', { req, providers: [{ provide: APP_BASE_HREF, useValue: req.baseUrl }] });
   });
 
   return server;

integration/express-engine-ve/server.ts

@@ -5,6 +5,7 @@ import * as express from 'express';
 import { join } from 'path';
 
 import { AppServerModuleNgFactory } from './src/main.server';
+import { APP_BASE_HREF } from '@angular/common';
 
 // The Express app is exported so that it can be used by serverless Functions.
 export function app() {
@@ -28,7 +29,7 @@ export function app() {
 
   // All regular routes use the Universal engine
   server.get('*', (req, res) => {
-    res.render('index', { req });
+    res.render('index', { req, providers: [{ provide: APP_BASE_HREF, useValue: req.baseUrl }] });
   });
 
   return server;

modules/express-engine/schematics/install/files/__serverFileName@stripTsExtension__.ts

@@ -5,6 +5,7 @@ import * as express from 'express';
 import { join } from 'path';
 
 import { AppServerModule } from './src/<%= stripTsExtension(main) %>';
+import { APP_BASE_HREF } from '@angular/common';
 
 // The Express app is exported so that it can be used by serverless Functions.
 export function app() {
@@ -28,7 +29,7 @@ export function app() {
 
   // All regular routes use the Universal engine
   server.get('*', (req, res) => {
-    res.render('index', { req });
+    res.render('index', { req, providers: [{ provide: APP_BASE_HREF, useValue: req.baseUrl }] });
   });
 
   return server;