This blog post talks as if mocking the `open` function is a good thing that people should be told how to do. If you are mocking anything in the standard library your code is probably structured poorly.
In the example the author walks through, a cleaner way would be to have the second function take the Options as a parameter and decouple those two functions. You can then test both in isolation.
In the example the author walks through, a cleaner way would be to have the second function take the Options as a parameter and decouple those two functions. You can then test both in isolation.