public async Task Given_An_AllFormats_Query_Should_Invoke_AllFormats_Method_Once() { // Arrange const int expected = 1; _formatService.AllFormats().Returns(new List <Format> { new Format { Id = 2342, Name = "Test Format", Acronym = "TF", Banlist = new List <Banlist>() }, new Format { Id = 23424, Name = "Test Format 2", Acronym = "TF", Banlist = new List <Banlist>() } }); // Act await _sut.Handle(new AllFormatsQuery(), CancellationToken.None); // Assert await _formatService.Received(expected).AllFormats(); }