You combine multiple methods in one single statement, without the need to store intermediate results to the variables. But each line can only contain 2 numbers s. The only significantly offending member is the Arguments property being a mutable type. Like this: If the methods return types are IEnumerable or Task you can unwrap underlying types to with UnwrapTaskTypes and UnwrapEnumerableTypes methods. When I asked others' opinions on how they read the above snippet, most of the answers I received were among the lines that the test verifies if the first name is correct and if the last name is correct. In this article, Ill show a few examples of how FluentAssertions can improve unit tests by comparing it with the built-in assertions (from Microsoft.VisualStudio.TestTools.UnitTesting). The following test uses the built-in assertions to check if the two references are pointing to the same object: Compare this with the FluentAssertions equivalent using Should().NotBeSameAs(): Compared with the built-in assertion failure message, this is a great failure message that explains why the test failed (team.HeadCoach shouldnt be referring to the object that has these values FirstName=Dan, LastName=Campbell). After writing in the edit field and. Is Koestler's The Sleepwalkers still well regarded? By looking at the error message, you can immediately see what is wrong. What if you want to only compare a few of the properties for equality? If any assertion of a test will fail, the test will fail. Occasional writer. Fluent Assertions' unique features and a large set of extension methods achieve these goals. In the OrderBL example above, the methods have been called in a sequence but youve had to write multiple lines of code one for each method call. What we really wanted here is to do an assert on each parameter using NUnit. You can also write custom assertions for your custom classes by inheriting from ReferenceTypeAssertions. Instead of thinking in single independent assertions (tests) cases within a test case, the better way to look at it would be to say "The test case verifies if the person is created correctly". But the downside is having to write the extra code to achieve it. So, whatever the object you are asserting, all methods are available. When needing to verify some method call, Moq provides a Verify-metod on the Mock object: [Test] public void SomeTest () { // Arrange var mock = new Mock<IDependency> (); var sut = new ServiceUnderTest (mock.Object); // Act sut.DoIt (); // Assert mock.Verify (x => x.AMethodCall ( It.Is<string> (s => s.Equals ("Hello")), Human Kinetics P.O. The Mock<T> class is given by Moq and allows us to create mocks that represents each of the services that we want to inject.We use the Object property to get the instance of the mocked service.. To mock a method or property we use the Setup() method, giving to it a lambda expression with the selected method and parameter.Then we use the Returns() method to tell the mock what it has to return . We could rewrite the assertion to use another method from FluentAssertions (for example BeEquivalentTo). Here is how we would test this: And here is the actual test with comments within the code for further clarification: Note: By default Moq will stub all the properties and methods as soon as you create a Mock object. "The person is created with the correct names". This mindset is where I think the problem lies. The goal of fluent interfaces is to make the code simple, readable, and maintainable. While method chaining usually works on a simple set of data, fluent interfaces are usually used to modify a complex object. A fluent interface is an object-oriented API that depends largely on method chaining. In addition, they allow you to chain together multiple assertions into a single statement. In testing this, it is important we can verify that the calls remain in the correct order. One might argue, that we compromise a bit with AAA, though. Can Mockito capture arguments of a method called multiple times? Copyright 2020 IDG Communications, Inc. Refresh the page, check Medium 's site. This method can screw you over. Is it possible to pass number of times invocation is met as parameter to a unit test class method? I mentioned this to @kzu, and he was suggesting that you migrate to Moq 5, which offers much better introspection into a mock's state and already includes the possibility to look at all invocations that have occurred on a mock. Making a "fluent assertion" on something will automatically integrate with your test framework, registering a failed test if something doesn't quite match. to compare an object excluding the DateCreated element. For example, lets say you want to test the DeepCopy() method. This makes it easy to understand what the assertion is testing for. // Will throw if the test code has didn't call HasInventory. In the Create new project window, select Console App (.NET Core) from the list of templates displayed. My experience has been that most application require passing more complex DTO-like arguments. I think there's probably a lot of overlap in these things: you can make clearer error messages if you understand the scenario better, knowing more about the expectations, and adding support for more specific scenarios gives you that additional knowledge. You could do that. Code needs to be readable in software development because it makes it easier for other developers to understand and contribute to the code base. Fluent Assertions is a set of .Net extension methods that allow you to more naturally specify the expected outcome of a TDD or BDD-style test. SomeInheritedOrDirectlyDecoratedAttribute, "because this is required to intercept exceptions", "because all Actions with HttpPost require ValidateAntiForgeryToken", "all the return types should be immutable". And for Hello! A Shouldly assertion framework is a tool used for verifying the behavior of applications. To give a simple example, let's take a look at the following tests. Moq Namespace. About Documentation Releases Github Toggle Menu Toggle Menu About A great one is always thinking about the future of the software. They are pretty similar, but I prefer Fluent Assertions since its more popular. Moq is a NuGet package, so before we can use it, we need to add it to our project via NuGet. For example, to verify that a string begins, ends and contains a particular phrase. If it cannot find any of the supported frameworks, it will fall back to using a custom AssertFailedException exception class. IEnumerable1 and all items in the collection are structurally equal. The most minimal, but still feasible API when we want to focus on Verify without blowing up the Setup stage might look like this: // Arrange: var a = new Mock < IFoo > (); var b = new Mock < IFoo > (); var seq = MockSequence. The Great Debate: Integration vs Functional Testing. The test creates a new person and verifies if the first name and the last name have the correct value. For loose mocks (which are the default), you can skip Setup and just have Verify calls. Note that because the return type of Save is void, the method chain shown in the preceding code snippet ends there. Also, you dont have to override Equals(object o) to get this functionality. The contract defined by Invocation is that the Return methods should ensure that these get properly written back for the calling code. I find that FluentAssertions improves the readability of the test assertions, and thus I can encourage you to take a look at it if you haven't already. @Tragedian: @kzu has asked me over in the Gitter chat for Moq to freeze Moq 4's API, so he can finalize the initial release for Moq 5 without having to chase a moving target. I haven't thought about it in detail, but the publicly visible Mock.Invocations would ideally appear to be a IReadOnlyList, where the interface type IInvocation defines two properties MethodInfo Method { get; } and IReadOnlyList