Mock Cloud Firestore

The best way i found to test cloud_firestore is to use Firestore.channel.setMockMethodCallHandler. But this requires knowledge of firebase protocol. This implementation tries to provide easier way.

First define the firestore data as json

  String source = r"""
{
  "goals": {
    "1": {
      "$": "Goal",
      "id": "1",
      "taskId": "1",
      "projectId": "1",
      "profileId": "1",
      "state": "ASSIGNED"
    }
  },
  "projects": {
    "1": {
      "id": "1",
      "$": "Project",
      "title": "test title",
      "description": "description",
      "contributors": [
        "2"
      ],
      "creatorProfileId": "3",
      "state": "INCOMPLETE"
    },
    "__where__": {
      "id == 1": {
        "1": {
          "id": "1",
          "$": "Project",
          "title": "test title",
          "description": "description",
          "contributors": [
            "2"
          ],
          "creatorProfileId": "3",
          "state": "INCOMPLETE"
        }
      }
    }
  },
  "tasks": {
    "1": {
      "id": "1",
      "$": "Task",
      "projectId": "123",
      "description": "test desc",
      "closeReason": "",
      "closeReasonDescription": "",
      "creatorProfileId": "123",
      "assigneeProfileId": "123",
      "state": "INCOMPLETE"
    }
  }
}
""";

create the mock

  MockCloudFirestore mcf = MockCloudFirestore(source);

now you can

main() {
  test("get a document", () async {
      MockCollectionReference col = mcf.collection("projects");
      MockDocumentReference docSnapshot = col.document("1");
      MockDocumentSnapshot docSnapshot = await doc.get();
      expect(docSnapshot.data["id"], "1");
      expect(docSnapshot.data["title"], "test project 1");
  });
}

main() {
  test("get snapshots", () async {
      MockCollectionReference col = mcf.collection("projects");
      Stream<QuerySnapshot> snapshots = col.snapshots();
      QuerySnapshot first = await snaphosts.first;
      expect(first, isNotNull);
      MockDocumentSnapshot docSnap = first.documents[0];
      expect(docSnap.data["id"], "1");
  });
}

To test widgets

create a backend to wrap firestore api

class BackendApi {
  CollectionGet collectionGet;

  BackendApi(this.collectionGet);

  Future<Map<String, dynamic>> project() async {
    DocumentReference docRef = collectionGet("projects").document("1");
    DocumentSnapshot docSnap = await docRef.get();
    return docSnap.data;
  }
}

remove firestore dependency from widget

class FirebaseDepWidget extends StatelessWidget {
  BackendApi backend;

  FirebaseDepWidget(this.backend);

  @override
  Widget build(BuildContext context) {
    return FutureBuilder(
      future: backend.project(),
      builder: (BuildContext context, AsyncSnapshot snapshot) {
        if (!snapshot.hasData) {
          return Text("Loading...");
        }
        return Text("${snapshot.data["title"]}");
      },
    );
  }
}

now you can mock out firestore

void main() {
  MockCloudFirestore mcf = getMockCloudFirestore();

  //BackendApi realBackend = BackendApi(Firestore.instance.collection);
  BackendApi mockBackend = BackendApi(mcf.collection);

  testWidgets('check task info ', (WidgetTester tester) async {
    await tester.pumpWidget(
      MaterialApp(
        home: Container(
          child: FirebaseDepWidget(mockBackend),
        ),
      ),
    );
    await tester.pump(Duration.zero); // Duration.zero is required or you get a timer exception
    expect(find.text("test project 1"), findsOneWidget);
  });
}

using where on collection

add expected results to collection node with __where__ key.See example on projects collection.

condition format

field name operator expected value

condition operators (in order)

• isEqualTo: ==
• isLessThen: <
• isLessThanOrEqualTo: =<
• isGreaterThen: >
• isGreaterThanOrEqualTo: =>
• arrayContains: 'array-contains'
• isNull: null

about condition order

dart does't give order guarantee to named arguments, so order is hard coded with in code. See operators for the order. Don't expect logical conditions like id > 1 & id < 5 this is not valid because of ordering, it must be like id < 5 & id > 1

examples

• id == 1
• id < 5 & id > 1multiple conditions concat with &, spaces are required
• id array-contains ["1", "2"] value should be json encoded