Warn when GCLOUD_PROJECT env variable does not exist (#200)

Author: kevmo314

spec/providers/firestore.spec.ts

@@ -33,15 +33,16 @@ describe('Firestore Functions', () => {
     };
   };
 
-  before(() => {
+  beforeEach(() => {
     process.env.GCLOUD_PROJECT = 'project1';
     process.env.FIREBASE_PROJECT = JSON.stringify({
       databaseUrl: '[email protected]',
     });
   });
 
-  after(() => {
+  afterEach(() => {
     delete process.env.GCLOUD_PROJECT;
+    delete process.env.FIREBASE_PROJECT;
   });
 
   describe('document builders and event types', () => {
@@ -60,6 +61,11 @@ describe('Firestore Functions', () => {
       expect(cloudFunction.__trigger).to.deep.equal(expectedTrigger(resource, 'document.write'));
     });
 
+    it('should throw useful error when GCLOUD_PROJECT missing', () => {
+      delete process.env.GCLOUD_PROJECT;
+      expect(() => firestore.document('users/{uid}')).to.throw(Error, 'GCLOUD_PROJECT');
+    });
+
     it('should allow custom namespaces', () => {
       let resource = 'projects/project1/databases/(default)/documents@v2/users/{uid}';
       let cloudFunction = firestore.namespace('v2').document('users/{uid}').onWrite(() => null);

src/providers/firestore.ts

@@ -35,6 +35,9 @@ export const defaultDatabase = '(default)';
 let firestoreInstance;
 
 export function database(database: string = defaultDatabase) {
+  if (!process.env.GCLOUD_PROJECT) {
+    throw new Error('Environment variable GCLOUD_PROJECT is not set.');
+  }
   return new DatabaseBuilder(posix.join('projects', process.env.GCLOUD_PROJECT, 'databases', database));
 }