>You cannot have quality software without these basic testing techniques
Of course you can, wtf?
Mock are often the reason of tests being green and app not working :)
Of course you can, wtf?
Mock are often the reason of tests being green and app not working :)
Explain then what is your alternative to unit and integration tests.
> Mock are often the reason of tests being green and app not working :)
I don't think that's a valid assumption. Tests just verify the system under test, and test doubles are there only to provide inputs in a way that isolates your system under test. If your tests either leave out invariants that are behind bugs and regressions or have invalid/insufficient inputs, the problem lies in how you created tests, not in the concept of a mock.
Workman and it's tools.
I am fine with having fake implementations and so forth, but the whole "when function X is called with Y arguments, return Z" thing is bad. It leads to very tight coupling of the test code with the implementation, and often means the tests are only testing against the engineer's understanding of what's happening - which is the same thing they coded against in the first place. I've seen GP's example of tests being green but the code not working correctly a number of times because of that.
This is pretty important since "unit tests" would be far too constraining for reasonable modifications to the compiler, e.g. adding a new pass could change the actual output code without modifying the semantics.
I mean they run single pass with some small llvm ir input and check if the output IR is fine
For example of such intertwined architecture see Mutter, a window manager of Gnome Shell (a program that manages windows on Linux desktop). A code that handles key presses (accessibility features, shortcuts), needs objects like MetaDisplay or MetaSeat and cannot be tested in isolation; you figuratively need a half of wayland for it to work.
The good tests use black box principle; i.e. they only use public APIs and do not rely on knowledge of inner working of a component. When the component changes, tests do not break. Tests with mocks rely on knowing how component work, which functions it calls; the tests with mocks become brittle, break often and require lot of effort to update when the code changes.
Avoid mocks as much as you can.
Tests against real components instead of mocks.
>If your tests either leave out invariants that are behind bugs and regressions or have invalid/insufficient inputs, the problem lies in how you created tests, not in the concept of a mock.
Nowadays external components can be very complex systems e.g dbs, messaging queues, 3rd APIs and so on
A lot of things can go wrong and you arent even aware of them in order to get mocks right.
Examples? fuckin emojis.
On mocked in memory database they work fine, but fail on real db due to encoding settings.
Wdym?
You're testing e.g simple crude operation, e.g create hn thread
With mocked db it passed, with real db it fails due to encoding issue.
The result is that tests are green, but app does not work.