repository_test.dart

//Note: This code is just for demonstration purpose

class MockRemoteDateSourceSuccess extends DataSource {
  @override
  Future<String> fetch() async {
    return Future.value("Mock Result");
  }
}

class MockRemoteDateSourceFailure extends DataSource {
  @override
  Future<String> fetch() async {
    throw SocketException("Mock exception");
  }
}

void main(){
  test("fetch() should return an instance of student on remoteDataSource's fetch success", () {
    Repository repo = Repository(MockRemoteDateSourceSuccess());
    final result = repo.fetch();
    expect(result, isInstanceOf<Student>());
  });

  test("fetch() should throw an exception on remoteDataSource's fetch throws any exception", () {
    Repository repo = Repository(MockRemoteDateSourceFailure());
    expect(() => repo.fetch(), throwsException);
  });
}