Mocks to write unit tests for Cloud Firestore. Instantiate a MockFirestoreInstance, then pass it around your project as if it were a FirestoreInstance. This mock will act like Firestore except it will only keep the state in memory. To help debug, you can use MockFirestoreInstance.dump() to see what's in the mock database. This is useful to mock the state of your database, then check that your UI behaves the way you expect.


A simple usage example

import 'package:cloud_firestore_mocks/cloud_firestore_mocks.dart';

void main() {
  final instance = MockFirestoreInstance();
  await instance.collection('users').add({
    'username': 'Bob',
  final snapshot = await instance.collection('users').getDocuments();
  print(snapshot.documents.length); // 1
  print(snapshot.documents.first['username']); // 'Bob'

// Prints out:
// {
//   "users": {
//     "z": {
//       "name": "Bob"
//     }
//   }
// }

See more examples at cloud_firestore_mocks/test/cloud_firestore_mocks_test.dart.

Usage in a UI test:

import 'package:cloud_firestore/cloud_firestore.dart';
import 'package:cloud_firestore_mocks/cloud_firestore_mocks.dart';
import 'package:firestore_example/main.dart';
import 'package:flutter/material.dart';
import 'package:flutter_test/flutter_test.dart';

const MessagesCollection = 'messages';

void main() {
  testWidgets('shows messages', (WidgetTester tester) async {
    // Populate the mock database.
    final firestore = MockFirestoreInstance();
    await firestore.collection(MessagesCollection).add({
      'message': 'Hello world!',
      'created_at': FieldValue.serverTimestamp(),

    // Render the widget.
    await tester.pumpWidget(MaterialApp(
        title: 'Firestore Example', home: MyHomePage(firestore: firestore)));
    // Let the snapshots stream fire a snapshot.
    await tester.idle();
    // Re-render.
    await tester.pump();
    // // Verify the output.
    expect(find.text('Hello world!'), findsOneWidget);
    expect(find.text('Message 1 of 1'), findsOneWidget);

See more examples at cloud_firestore_mocks/example/test/widget_test.dart.


  • Dump the state of the mock firebase with MockFirestoreInstance.dump().
  • Create documents and collections.
  • Create documents with collection.add or document.setData.
  • Batch writes and runTransaction.
  • Query documents with collection.snapshots or query.getDocuments.
  • Queries:
    • Filter results with query.where. The library supports equals, isGreaterThan, isGreaterThanOrEqualTo, isLessThan, and isLessThanOrEqualTo.
    • Sort results with query.orderBy.
    • Limit results with query.limit.
  • ValueField:
    • set timestamps with FieldValue.serverTimestamp().
    • delete values with FieldValue.delete().
    • update numerical values with FieldValue.increment.
    • update arrays with FieldValue.arrayUnion and FieldValue.arrayRemove.

Features and bugs

Please file feature requests and bugs at the issue tracker.


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