mock

> The "os.listdir()" example in this blog is a pretty common case, using mocks to test code that works with filesystems, where you don't need or want to get involved with actually creating filesystems which may be a complex and expensive process, especially if the test suite runs concurrent processes. Alternative: have an abstract base class that describes a file system API. Have one implementation that builds on top of OS primitives and have another one that is a mock (potentially auto-generated through some mocking framework). That way there is no need to monkey-patch standard library functions at runtime. I did that within a project of mine, written in Go: https://github.com/buildbarn/bb-storage/blob/master/pkg/file... https://github.com/buildbarn/bb-storage/blob/master/pkg/file... Pretty slick that I can now use https://github.com/gol