test: Introduce fakes for app config

[artonge]

The goal is to reduce the dependence of most tests on actual implementation and in the end the database.
This also make it much easier to prepare the environment for tests.

I used the fake in some tests to try out, and it is indeed easy and clean.

[ChristophWurst]

This is more of a convenience helper, right? Because mocks already allow us to have that

[artonge]

This is more of a convenience helper, right? Because mocks already allow us to have that

My problem with mocks is that it is super lengthy to configure all the expected interactions that the tested method will have. Also, it binds the test to the implementation, so every time the implementation changes, the test needs to change too.

Currently, this is rather an experiment, I'll try to pick it up again when I have time.

[ChristophWurst]

I agree for tests that use the at/consecutive pattern. They are fragile and you are indeed testing the internals.

(App) config should be arranged like $config->method('getValueBool')->with('maintenance')->willReturn(true) so call order doesn't matter. In fact it doesn't even matter if the config is fetched or not. You just set up the environment.

Just my 2c