There's a bug in the following code:
def test_should_filter_foobar_by_foo_id(self) -> None:
first_foo = Foo(name="a")
second_foo = Foo(name="b")
first_foobar = FooBar(foo=first_foo)
second_foobar = FooBar(foo=second_foo)
results = FooBarFilter(data={"foo": first_foobar.id}
self.assertListEqual([first_foobar], results.qs.order_by("id"))
The test passes for the wrong reason, because when starting from a newly initialized DB the Foo.id
and FooBar.id
sequences both start at 1. first_foobar.id
should be first_foo.id
. This is very similar to real-world tests I've written where the sequences running in lockstep has caused misleading test implementations.
Is there a (cheap, simple) way to do something similar to Django's reset_sequences
to jolt all the sequences out of lockstep? Whether randomly or by adding 1 million to the first sequence, 2 million to the next etc., or some other method. A few suboptimal options come to mind:
- Create dummy instances at the start of the test to move the sequences out of lockstep.
- Prohibitively expensive.
- Error prone because we'd have to keep track of how many instances of each model we create.
- Adds irrelevant complexity to the tests.
- Change the current values of each sequence as part of test setup.
- Error prone because we'd have to make sure to change all the relevant sequences as we add more models to the tests.
- Adds irrelevant complexity to the tests.
- Swap around the order in which we create the instances in the test, so that
first_foo
has ID 2 andsecond_foo
has ID 1.- Adds irrelevant complexity to the tests.
- Once we have three or more models in the test at least two of them will be in lockstep, and we'd need to complement this with some other technique.
- Modify the IDs of each instance after saving, thereby bypassing the sequences entirely.
- Again, adds irrelevant complexity to the tests.
- Error prone, since now it would be easy to accidentally end up with ID collisions.
- Change the current values of each sequence as part of the template DB. I'm not sure how to do this, and I'm not sure how expensive it would be.
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