Developer argues for writing custom test doubles over using mocking libraries

A software developer explains they have stopped using popular mocking libraries like Moq or NSubstitute. They argue that writing custom test doubles, such as fakes, results in less cluttered and more readable test code. The developer states that custom test doubles reduce coupling to implementation details, making tests more resilient to changes in the underlying code. They also claim this approach provides more freedom during implementation and can be accelerated with the help of AI coding assistants.