public async Task LeaveGroup_Success_NotifyCurrentAndAllConnection() { var testPayload = new UserWssPayload { GroupId = TestGroupId }; var testGroup = new Group { Id = TestGroupId }; _chatServiceMock .Setup(s => s.LeaveGroupAsync(TestUserId, TestGroupId)) .Returns(Task.CompletedTask); _chatServiceMock .Setup(s => s.GetGroupAsync(testGroup.Id)) .ReturnsAsync(testGroup); await _target.LeaveGroup(testPayload); AssertMessageSentToCurrentConnection(ChatHub.LeaveSuccessMessage, content => (string)content == TestGroupId); AssertMessageSentToAllConnections(ChatHub.MemberLeftMessage, content => ((MemberChangeResponse)content).Group == testGroup); }