Coming up with guidelines on how we write tests (3410)

[GalacticEmperor1]

Issue №3410 opened by illume at 2022-08-20 08:27:52

Was thinking about improvements to our tests to make them easier to read.

Many of the tests were written in a time before best practices were known, and also before python even included the unit test module! We never really made a guide of how we should do them. Some files follow different styles a bit too.

Here's one example from the math tests (which follows the style of the other tests in that file):

    def test_move_towards_max_distance(self):

        expected = Vector3(12.30, 2021, 42.5)

        origin = Vector3(7.22, 2004.0, 17.5)

        change_ip = origin.copy()



        change = origin.move_towards(expected, 100)

        change_ip.move_towards_ip(expected, 100)



        self.assertEqual(change, expected)

        self.assertEqual(change_ip, expected)

A few ideas:

def test_move_towards_does_not_go_past(self):

    """It should stop at the destination vector and not go past it."""



    origin = Vector3(7.22, 2004.0, 17.5)

    destination = Vector3(12.30, 2021, 42.5)

    distance_too_far = 100

    self.assertEqual(origin.move_towards(destination, distance_too_far), destination)

    self.assertNotEqual(origin.distance_to(destination), distance_too_far, "we didn't go that far")



def test_move_towards_does_not_go_past_ip(self):

    """It should stop at the destination vector and not go past it. In place operation."""



    origin = Vector3(7.22, 2004.0, 17.5)

    destination = Vector3(12.30, 2021, 42.5)

    too_far = 100

    origin.move_towards_ip(destination=destination, distance=too_far)

    self.assertEqual(origin, destination, "it changed in place")

    self.assertNotEqual(origin.distance_to(destination), too_far, "we didn't go that far")

• how the test should be named

• Naming the variables (distance = 100)

• testing one thing at a time

• use keyword arguments

• using the message part of the assertion (and how that should be written)

• using the test doc string (and how that should be written)

• using keyword arguments (here with move_towards the argument names are not documented).

This example and list aren't necessarily correct or good, but a starting point. I guess there are a good set of best practices we could settle on. Then those guidelines can be documented, and the big process of going through all the tests for improvement can begin.

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