FakeXrmEasy is an invaluable tool for development of Dynamics CRM/365/Dataverse software and using it will make your life as a developer much easier and will undoubtedly help you write more robust, maintainable code. FakeXrmEasy implements an in-memory version of the XRM database and provides mocked version of most of the main methods provided by the IOrganisation service. You may, however, occasionally come across a method which has not been implemented in the library. When you test code which calls one of these methods, your test will fail with a message like this: The organization request type 'Microsoft.Crm.Sdk.Messages.NameOfTheUnimplementedRequest' is not yet supported... but we DO love pull requests so please feel free to submit one! :). This functionality is not available yet. Please consider contributing to the following Git project https://github.com/jordimontana82/fake-xrm-easy by cloning the repository and issuing a pull request."
When writing Unit tests one can focus on two different aspects of the code under test. We can call these two types of test ‘State-based’ and ‘Interaction-based’. The first of these concentrates on the end result achieved by the code under test – ie, what was the result of the code being run, whereas the second focuses on how that result was achieved.