如何在go中模拟对ioutil.ReadFile的调用？

Question

I have the following function:

func ObtainTranslationStringsFile(path string) ([]string, error) {
    if contents, err := ioutil.ReadFile(path); err != nil {
        return ObtainTranslationStrings(string(contents))
    } else {
        return nil, err
    }
}

I need to mock ioutil.ReadFile, but I'm not sure how to do it. Is it possible?

Answer 1

Don't mock ioutil.ReadFile. Once you mocked it, testing ObtainTranslationStringsFile wouldn't test any more than testing ObtainTranslationStrings would. If you need to test ObtainTranslationStringsFile, create a temporary file and pass its path to ObtainTranslationStringsFile. That way you will actually test the functionality that is added by that function.