Add test, update error message

Author: hsubox76

packages/app/src/api.test.ts

@@ -206,6 +206,13 @@ describe('API tests', () => {
     it('throws retrieving a non existing App (default name)', () => {
       expect(() => getApp()).throws(/No Firebase App/);
     });
+
+    it('does not throw on a non existing App (default name) if a defaults object exists', () => {
+      global.__FIREBASE_DEFAULTS__ = { config: { apiKey: 'abcd' } };
+      const app = getApp();
+      expect(app.options.apiKey).to.equal('abcd');
+      global.__FIREBASE_DEFAULTS__ = undefined;
+    });
   });
 
   describe('getApps', () => {

packages/app/src/errors.ts

@@ -34,7 +34,7 @@ export const enum AppError {
 const ERRORS: ErrorMap<AppError> = {
   [AppError.NO_APP]:
     "No Firebase App '{$appName}' has been created - " +
-    'call initializeApp()',
+    'call initializeApp() first',
   [AppError.BAD_APP_NAME]: "Illegal App name: '{$appName}",
   [AppError.DUPLICATE_APP]:
     "Firebase App named '{$appName}' already exists with different options or config",