Unit tests for private methods are a code smell
This week I attended a talk where some people were discussing techniques for unit testing private methods — they were going on about problems they had getting something called Private Accessors to work with ReSharper.
The tools they mentioned were completely foreign to me, and I wondered why I’d never heard of them. I think the reason is because I never bothered trying to test a private method before.
I take the approach that, if you have a private method worthy of having its own tests, then it is worthy of being extracted to a public method on a new class. Tests for private methods are a big smell you have an SRP violation somewhere. And they will be brittle anyway so just don’t do it!