atako / mock-cloud-firestore

Mock library for Cloud Firestore

mock-cloud-firestore

Mock library for Cloud Firestore

Installation

Install the library by running this command:

npm install --save-dev mock-cloud-firestore

Importing

Browsers

Import the mock-cloud-firestore.js file from the dist/browser folder in your app

Node.js

Import the library by using require('mock-cloud-firestore')

Usage

MockFirebase

MockFirebase class is provided to replace your app's Firebase instance

const firebase = new MockFirebase(fixtureData);

Replacing the Firebase instance depends on how your app consumes it. As an example, you could do window.firebase = new MockFirebase(fixtureData) on a browser environment.

Using in test environment

If you're using firebase as-is like a global variable you could do:

window.firebase = new MockFirebase(fixtureData);
const db = firebase.firestore();

db.collection('users').add({ ... });

If you're passing firebase as a param in a function (dependency injection) you could do:

function initialiseApp(firebaseDependency) {
  const db = firebaseDependency.firestore();

  db.collection('users').add({ ... });
}

// then in your test file
const firebaseDependency = new MockFirebase(fixtureData);
initialiseApp(firebaseDependency);

Fixture Data

Here's a sample fixture data

const fixtureData = {
  __collection__: {
    users: {
      __doc__: {
        user_a: {
          age: 15,
          username: 'user_a',

          __collection__: {
            friends: {
              __doc__: {
                user_b: {
                  reference: '__ref__:users/user_b'
                }
              }
            }
          }
        },

        user_b: {
          age: 10,
          username: 'user_b',

          __collection__: {
            friends: {
              __doc__: {
                user_a: {
                  reference: '__ref__:users/user_a'
                }
              }
            }
          }
        },

        user_c: {
          age: 20,
          username: 'user_c'
        }
      }
    }
  }
}

Here's whats going on with the example above

• There will be a users collection
• There will be user_a, user_b, and user_c documents under users collection
• There will be a friends subcollection under user_a and user_b documents
• __ref__: indicates that this is a Reference data type to a document
  • __ref__:users/user_a will be equivalent to firestore.collection('users').doc('user_a')

Caveats

Not all APIs are supported. Here are some unsupported major ones

• Transaction
• onSnapshot() is supported but doesn't get realtime updates

You can look into the source code to see if an API you're using is supported. I've written it in a way that you could quickly scan the APIs.

Developing

Installation

• git clone <repository-url> this repository
• cd mock-cloud-firestore
• npm install

Running Tests

• npm test