Firebase App named '[DEFAULT]' already exists (app/duplicate-app)

问题

Hi I am trying to unit test while developing a simple web with AngularJS + Firebase, but I have a problem defining the spec and trying the test runner

myProject/test/spec/main.js :

describe('Controller: MainCtrl', function() {

var MainCtrl, scope

beforeEach(module('MainApp'));

beforeEach(inject(function ($controller, $rootScope) {
    scope = $rootScope.$new();
    MainCtrl = $controller('MainCtrl', {
        $scope: scope
    })
}));

it('should....',function(){
    expect(true).toBe(true)
})
it('should2....',function(){
    expect(false).toBe(false)
})
});

result:

PhantomJS 2.1.1 (Mac OS X 0.0.0) Controller: MainCtrl should.... FAILED
Error: [$injector:modulerr] Failed to instantiate module MainApp due 
to: Firebase: Firebase App named '[DEFAULT]' already exists 
(app/duplicateapp).

However, defining the spec once is not a problem. For example:

it('should....',function(){
   expect(true).toBe(true)
})

I do not know why this is the reason I give a hint to me

Here is the project I am developing.

https://github.com/parkwookyun/firebase-angular-board

回答1:

if (!firebase.apps.length) {
   firebase.initializeApp({});
}

回答2:

I had the same issue using firebase, and I discover that I was initializing the firebase twice, example:

function initializeFirebase(){    
 var config = {
    apiKey: "myApiKey",
    authDomain: "myAuthDomain",
    databaseURL: "myDatabaseUrl",
    storageBucket: "myStorageBocket",
    messagingSenderId: "idhere"   
   };   
   //initialize firebase  
   firebase.initializeApp(config);  
}

In my case I was using react, And I was calling initializeFirebase() from two different components, but I've decided to call it from the parent component. And now I'm able to query my database, insert records, remove, etc.

Hope this helps someone

回答3:

i only glanced at your github repo to see that there is more .js files than suggested in your question. i had 2 separate .js files. both being included on the same html page that were both configuring and initializing the default app when it only needed to be done once for that page i believe. what worked for me was to comment out the second "initializeApp()" and i no longer got that error. try to look for the below in your .js and comment out or delete one of the initializations.

var config = { apiKey: "my api key", authDomain: "something.firebaseapp.com", databaseURL: "https://somesite.firebaseio.com", projectId: "myProjectId", storageBucket: "somesite.appspot.com", messagingSenderId: "someIntegers" }; //firebase.initializeApp(config);

回答4:

I recently solved this issue in my own code. My issue was caused by accidentally linking my javascript file, which calls initializeApp(), in the head and in the body of my html file. My fix was to delete the duplicate javascript tag in the head of my html file so only one existed in the body.

Scan through your code to make sure you only call initializeApp() once. This includes any js files that might be calling the method or duplicating the js file in your html file.