The document discusses testing and mocking with the Moq framework. It covers different types of tests like unit tests, integration tests, and acceptance tests. It also discusses the AAA pattern for arranging, acting, and asserting in tests. The document dives into code dependencies, priorities for testing, and how mocking with Moq can help isolate components for testing. It provides examples of creating mocks with Moq and verifying mock behavior using methods like Returns, Callback, and It.

1. TESTING AND MOCKING
WITH THE MOQ FRAMEWORK
BY: ARTHUR CHARLTON
EMAIL: LYNXSTAR@KERVANA.COM

2. UNIT TESTS VS “UNIT TESTS”
• Different test types
• Unit Test – Atomic, method sized, used for TDD, isolated
• Functional/Feature Test – Story/task requirements, isolated
• Acceptance Test – Black box test of a piece of functionality by itself
• Integration Test – Black box testing of the system as a whole, test
harness

3. AAA PATTERN
• Arrange – Configure testing infrastructure (mocking, DI, etc)
• Act – Execute the method under test
• Assert – Verify results

4. CODE DEPENDENCIES
• Dependency Inversion Principle is your friend
• Spaghetti Code is hard to test
• Heavily coupled code is hard to isolate for unit and functional
testing
• Coupled code can lead to large unit tests.
• Depend on abstractions not concretions

5. TESTING PRIORITIES
• Output
• Service Dependencies
• State

6. MOCKING
• Assists in isolating the method/class/component under test.
• Allows you to simulate parts of the system during test
• Isolation helps with unit test and functional test level problems

7. MOQ
• .NET Mocking Framework
• Handles mocking boilerplate
• Gives you powerful assertion tools
• Can mock both abstraction and virtual concretions

8. CREATING A MOQ

9. VERIFY
• Used to assert that a moq method has been called under
certain conditions
• Allows you verify the amount of calls
• Allows you to verify the parameters passed in

10. VERIFY - TIMES
• The Times struct lets you specific invocation amount
restrictions when verifying.
• Exactly
• At Most
• At Least
• Between
• Once/Never as convenience

11. VERIFIABLE - EXAMPLE

12. SETUP - RETURNS
• Allows you to configure what a mocked out method will return
• Chain .Returns(delegate) onto a setup method.
• Return delegate
• Type of Func<ParameterType1, ParameterType2,… ReturnType>
• Input: All method arguments
• Output: Method output
• Great place to use lambda expressions

13. RETURNS - EXAMPLE

14. CONTINUED

15. RETURN PITFALLS
• Be careful of shortcuts.
• Returns(SomeCollection.Count) will only be evaluated once,
regardless of how many times the mocked method is invoked
• Returns(() => SomeCollection.Count) will be evaluated every
time.
• This applies to just returning a variable too, if for some reason
this would change in between invocations you need to use a
delegate.

16. CALLBACKS
• Arbitrary block of code to be executed every time a mocked out
method is invoked.
• Useful for functional testing when trying to simulate parts of
the system.
• Similar to returns it takes in a delegate
• Action, matching the parameter type/order
• No returns
• You can chain a callback to a return

17. CALLBACKS

18. THE POWER OF IT
• It is a special class that is a part of MoQ
• Allows you to configure mocked method arguments in a
generic manner

19. IT - SETUP

20. IT- VERIFY

21. IT – VARIATIONS
• It.Is
• Func<Ptype, bool> - Pass it a delegate that determines if it is a match
• It.IsAny<Ptype> (Most commonly used)
• Passes if parameter is the supplied type
• It.IsIn
• Passes if parameter is in the supplied collection
• It.Regex
• Passes if string parameter passes the regex, fails if not string parameter

22. QUESTIONS/DEMO
• Any questions?
• Time to show off some real code running with MoQ