TestCaseSource

TestCaseSource is a concept commonly found in unit testing frameworks, particularly in .NET with the NUnit framework. It is an attribute that allows a test method to specify a separate method or property from which it can obtain the test data. This is a powerful technique for data-driven testing, where a single test method can be executed multiple times with different sets of input values and expected outcomes.

When a test method is decorated with the TestCaseSource attribute, the framework will invoke the specified source method or property. This source must return a collection of test cases. Each test case typically consists of the arguments that will be passed to the test method. The TestCaseSource attribute can take a string name of the source method or property, or it can reference the source directly.

Using TestCaseSource offers several advantages. It promotes code reusability by separating test logic from test data. This makes tests cleaner, more maintainable, and easier to read. It also allows for a more structured approach to defining complex test scenarios. Developers can define their test data in a dedicated location, making it easy to add, modify, or remove test cases without altering the test method itself. This is particularly useful when dealing with large datasets or intricate input combinations.