Not sure why she says static methods are easier to test:
In isolation, when testing the class that contains the method it really doesn’t matter whether it’s static or not - both are as easy to test.
In a larger system, when collaborating with other classes, using static functions is harder to test because you can’t1 swap them out at runtime. So if the static method accesses a database for example, it’s not possible to write to a fake (in-memory) database during tests, while this would be possible if it was a dynamic method on class that was injected.
Why exactly does she state that static methods are easier to test?
Also, it’s not a design pattern, but using static methods all over the place is usually a violation of the Depency Inversion Principle.
As far as I know there is no design pattern that really cares about static methods - that’s not what design patterns are about.
1 edited; it said can, but that’s incorrect