Enable firestore sdk to talk to emulator

packages/testing/index.ts

@@ -26,5 +26,6 @@ export {
   assertSucceeds,
   initializeAdminApp,
   initializeTestApp,
+  initializeFirestoreTestApp,
   loadDatabaseRules
 } from './src/api';

packages/testing/src/api/index.ts

@@ -14,9 +14,12 @@
  * limitations under the License.
  */
 
+import { firebase } from '@firebase/app';
 import * as admin from 'firebase-admin';
 import request from 'request-promise';
 import * as fs from 'fs';
+import { FirebaseApp } from '@firebase/app-types';
+import { base64 } from '@firebase/util';
 
 const DBURL = 'http://localhost:9000';
 
@@ -64,6 +67,34 @@ export function initializeTestApp(options: any): admin.app.App {
   );
 }
 
+export function initializeFirestoreTestApp(options: any): FirebaseApp {
+  if (!('projectId' in options)) {
+    throw new Error('projectId not specified');
+  }
+  if (typeof options.auth != 'object') {
+    throw new Error('auth must be an object');
+  }
+  var header = {
+    alg: 'RS256',
+    kid: 'fakekid'
+  };
+  var fakeToken = [
+    base64.encodeString(JSON.stringify(header), /*webSafe=*/ true),
+    base64.encodeString(JSON.stringify(options.auth), /*webSafe=*/ true),
+    'fakesignature'
+  ].join('.');
+  let app = firebase.initializeApp(
+    {
+      projectId: options.projectId,
+      tokenOverride: fakeToken
+    },
+    'app-' + new Date().getTime() + '-' + Math.random()
+  );
+  (app as any).INTERNAL.getToken = () =>
+    Promise.resolve({ accessToken: fakeToken });
+  return app;
+}
+
 export type LoadDatabaseRulesOptions = {
   databaseName: String;
   rules: String;

packages/testing/test/database.test.ts

@@ -84,6 +84,47 @@ describe('Testing Module Tests', function() {
     );
   });
 
+  it('initializeFirestoreTestApp() throws if no projectId', function() {
+    expect(
+      firebase.initializeFirestoreTestApp.bind(null, { auth: {} })
+    ).to.throw(/projectId not specified/);
+    expect(
+      firebase.initializeFirestoreTestApp.bind(null, {
+        projectId: 'foo',
+        auth: {}
+      })
+    ).to.not.throw();
+  });
+
+  it('initializeFirestoreTestApp() throws if auth is not an object', function() {
+    expect(
+      firebase.initializeFirestoreTestApp.bind(null, {
+        projectId: 'a',
+        auth: 'b'
+      })
+    ).to.throw(/auth must be an object/);
+    expect(
+      firebase.initializeFirestoreTestApp.bind(null, {
+        projectId: 'a',
+        auth: {}
+      })
+    ).to.not.throw();
+  });
+
+  it('initializeFirestoreTestApp() uses specified auth.', function() {
+    let app = firebase.initializeFirestoreTestApp({
+      projectId: 'foo',
+      auth: {}
+    });
+    expect(app.options).to.have.any.keys('tokenOverride');
+
+    app = firebase.initializeFirestoreTestApp({
+      projectId: 'foo',
+      auth: { uid: 'alice' }
+    });
+    expect(app.options).to.have.any.keys('tokenOverride');
+  });
+
   it('loadDatabaseRules() throws if no databaseName or rulesPath', async function() {
     expect(firebase.loadDatabaseRules.bind(null, {})).to.throw(
       /databaseName not specified/