firebase - Flutter 单元测试 Firestore

Question

总的来说，我是单元测试的新手。我正在尝试从我的 DataRepository 测试简单的方法。

点击此链接但似乎已弃用:https://utkarshkore.medium.com/writing-unit-tests-in-flutter-with-firebase-firestore-72f99be85737

class DataRepository {
  final CollectionReference collection =
      FirebaseFirestore.instance.collection('notes');

  //Retour de models a la place de snapshots
  Stream<QuerySnapshot> getStream() {
    return collection.snapshots();
  }

  Stream<QuerySnapshot> getStreamDetail(String id) {
    return collection.doc(id).collection('tasks').snapshots();
  }

  Stream<List<Note>> noteStream() {
    final CollectionReference collection =
        FirebaseFirestore.instance.collection('notes');

    try {
      return collection.snapshots().map((notes) {
        final List<Note> notesFromFirestore = <Note>[];
        for (var doc in notes.docs) {
          notesFromFirestore.add(Note.fromSnapshot(doc));
        }
        return notesFromFirestore;
      });
    } catch (e) {
      rethrow;
    }
  }

到目前为止，这是我的测试文件的样子:

import 'package:cloud_firestore/cloud_firestore.dart';
import 'package:flutter_test/flutter_test.dart';
import 'package:mockito/mockito.dart';

class MockFirestore extends Mock implements FirebaseFirestore {}
class MockCollectionReference extends Mock implements CollectionReference {}

void main() {
  MockFirestore instance = MockFirestore();
  MockCollectionReference mockCollectionReference = MockCollectionReference();

  test('should return data when the call to remote source is succesful.',
      () async {
    when(instance.collection('notes')).thenReturn(mockCollectionReference);
  });
}

第一个实例抛出这个错误

The argument type 'MockCollectionReference' can't be assigned to the parameter type 'CollectionReference<Map<String, dynamic>>'

非常感谢测试该方法的帮助。

新编辑:

void main() {
  test('should return data when the call to remote source is succesful.',
      () async {
    final FakeFirebaseFirestore fakeFirebaseFirestore = FakeFirebaseFirestore();
    final DataRepository dataRepository = DataRepository();
    final CollectionReference mockCollectionReference =
        fakeFirebaseFirestore.collection(dataRepository.collection.path);

    final List<Note> mockNoteList = <Note>[];

    for (Note mockNote in mockNoteList) {
      await mockCollectionReference.add(mockNote.toJson());
    }

    final Stream<List<Note>> noteStreamFromRepository =
        dataRepository.noteStream();

    final List<Note> actualNoteList = await noteStreamFromRepository.first;
    final List<Note> expectedNoteList = mockNoteList;

    expect(actualNoteList, expectedNoteList);
  });
}

Answer 1

您可以使用 fake_cloud_firestore使用 FakeCloudFirestore 模拟 Firestore 实例可用于代替实际 FirebaseFirestore 的对象对象。

一个例子:

 import 'package:cloud_firestore/cloud_firestore.dart';
 import 'package:fake_cloud_firestore/fake_cloud_firestore.dart';

 test('noteStream returns Stream containing List of Note objects', () async {
      //Define parameters and objects

      final FakeFirebaseFirestore fakeFirebaseFirestore = FakeFirebaseFirestore();

      final DataRepository dataRepository =
          DataRepository(firestore: fakeFirebaseFirestore);

      final CollectionReference mockCollectionReference =
          fakeFirebaseFirestore.collection(dataRepository.collection.path);

      final List<Note> mockNoteList = [Note()];

      // Add data to mock Firestore collection
      for (Note mockNote in mockNoteList) {
        await mockCollectionReference.add(mockNote.toSnapshot());
      }

      // Get data from DataRepository's noteStream i.e the method being tested
      final Stream<List<Note>> noteStreamFromRepository =
          dataRepository.noteStream();

      final List<Note> actualNoteList = await noteStreamFromRepository.first;

      final List<Note> expectedNoteList = mockNoteList;

      // Assert that the actual data matches the expected data
      expect(actualNoteList, expectedNoteList);
    });

解释:

上面的测试对您的代码做了以下假设:

• 您通过 FirebaseFirestore对象进入 DataRepository对象。
• 您有一个 toSnapshot您的 Note 上的方法转换您的 Note 的对象对象变成 Map<String, dynamic>对象。

测试按以下方式进行:

1. 它创建测试所需的必要对象，即 FakeFirebaseFirestore对象，DataRepository对象，模拟 CollectionReference对象和要传递到模拟集合引用 (mockNoteList) 的模拟数据。
2. 它将数据添加到模拟集合引用中。
3. 它使用 DataRepository 获取数据的noteStream方法。
4. 它断言来自 DataRepository 的实际数据等于预期数据，即最初传递给模拟集合引用的数据。

资源:

如需进一步了解 Flutter 中的单元测试 Firestore，请查看以下资源:

• FlutterFire's Documentation on Testing ，关于如何使用 fake_cloud_firestore 的概述打包在 Flutter 中的小部件测试中。
• Mocking and Testing Firestore Operations in Flutter Unit Tests | Part 1 (Documents and Collections) ，一篇关于使用 fake_cloud_firestore 的文章在 Flutter 单元测试中测试 Firestore 操作的包，由我编写。

更新

将 FirebaseFirestore 对象添加为您的构造函数参数之一，并使用它来代替 FirebaseFirestore.instance .

更新您的DataRepository到下面这个:

class DataRepository {
  DataRepository({required this.firestore});

  final FirebaseFirestore firestore;

   CollectionReference get collection =>
     firestore.collection('notes');

  //Retour de models a la place de snapshots
  Stream<QuerySnapshot> getStream() {
    return collection.snapshots();
  }

  Stream<QuerySnapshot> getStreamDetail(String id) {
    return collection.doc(id).collection('tasks').snapshots();
  }

  Stream<List<Note>> noteStream() {
    try {
      return collection.snapshots().map((notes) {
        final List<Note> notesFromFirestore = <Note>[];
        for (var doc in notes.docs) {
          notesFromFirestore.add(Note.fromSnapshot(doc));
        }
        return notesFromFirestore;
      });
    } catch (e) {
      rethrow;
    }
  }

更新的 DataRepository 使用:

• 在测试中:

 final FakeFirebaseFirestore fakeFirebaseFirestore = FakeFirebaseFirestore();
 final DataRepository dataRepository =
          DataRepository(firestore: fakeFirebaseFirestore);

• 在应用中:

 final FirebaseFirestore firebaseFirestore = FirebaseFirestore.instance;
 final DataRepository dataRepository =
          DataRepository(firestore: firebaseFirestore);