Mock library for Cloud Firestore

Assuming that you're using npm as your package manager:

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

If you're not using any module bundler, you can use the precompiled UMD builds in the dist folder. For this build, MockFirebase would be available as a window.MockFirebase global variable. You can download the files at unpkg.

This accepts the following option:

• isNaiveSnapshotListenerEnabled - When true, changes to any data would cause the onSnapshot() to fire. Otherwise, onSnapshot() won't get realtime updates.

You'll need to replace the Firebase instance that you're app is using. That would depend on how you use it. Below are some sample use-cases:

Example 1 - Overriding the Firebase global variable

import MockFirebase from 'mock-cloud-firestore';

window.firebase = new MockFirebase(fixtureData);

const db = firebase.firestore();

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

Example 2 - Dependency injection

import MockFirebase from 'mock-cloud-firestore';

function addUser(firebase) {
  return firebase.firestore.collection('users').add({ ... });
}

const firebase = new MockFirebase(fixtureData);

addUser(firebase);

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')

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

• Transaction
• onSnapshot() is supported but doesn't get realtime updates by default.
  • A naive listener is available in that changes to any data would cause it to fire.

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.

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

• npm test