In order to allow users to type annotate fixtures they request, the
types need to be imported from the `pytest` namespace. They are/were
always available to import from the `_pytest` namespace, but that is
not guaranteed to be stable.
These types are only exported for the purpose of typing. Specifically,
the following are *not* public:
- Construction (`__init__`)
- Subclassing
- staticmethods and classmethods
We try to combat them being used anyway by:
- Marking the classes as `@final` when possible (already done).
- Not documenting private stuff in the API Reference.
- Using `_`-prefixed names or marking as `:meta private:` for private
stuff.
- Adding a keyword-only `_ispytest=False` to private constructors,
warning if False, and changing pytest itself to pass True. In the
future it will (hopefully) become a hard error.
Hopefully that will be enough.
It turns out all autouse fixtures are kept in a global list, and thinned
out for a particular node using a linear scan of the entire list each
time.
Change the list to a dict, and only take the nodes we need.
ischildnode can be quite hot in some cases involving many fixtures.
However it is always used in a way that the nodeid is constant and the
baseid is iterated. So we can save work by pre-computing the parents of
the nodeid and use a simple containment test.
The `_getautousenames` function has the same stuff open-coded, so change
it to use the new function as well.
This indicates at least for people using type checkers that these
classes are not designed for inheritance and we make no stability
guarantees regarding inheritance of them.
Currently this doesn't show up in the docs. Sphinx does actually support
`@final`, however it only works when imported directly from `typing`,
while we import from `_pytest.compat`.
In the future there might also be a `@sealed` decorator which would
cover some more cases.
This makes mypy raise an error whenever it detects code which is
statically unreachable, e.g.
x: int
if isinstance(x, str):
... # Statement is unreachable [unreachable]
This is really neat and finds quite a few logic and typing bugs.
Sometimes the code is intentionally unreachable in terms of types, e.g.
raising TypeError when a function is given an argument with a wrong
type. In these cases a `type: ignore[unreachable]` is needed, but I
think it's a nice code hint.
This prevents referring to a generic type without filling in its generic
type parameters.
The FixtureDef typing might need some more refining in the future.
We barely use it; the couple places that do are not really worth the
extra dependency, I think the code is clearer without it.
Also simplifies one (regular) itertools usage.
Also improves a check and an error message in `pytest.raises`.
The previous typing had an object passed to the user, which they can't
do anything with without asserting, which is inconvenient. Change it to
Any instead.
Note that what comes *back* to pytest (the return value) should be an
`object`, because we want to handle arbitrary objects without assuming
anything about them.
This option checks even functions which are not annotated. It's a good
step to ensure that existing type annotation are correct.
In a Pareto fashion, the last few holdouts are always the ugliest,
beware.
The FixtureFunctionMarker attrs class already converts the params
itself.
When adding types, the previous converter composition causes some type
error, but extracting it to a standalone function fixes the issue (a
lambda is not supported by the mypy plugin, currently).
pytest.fixture() can be used either as
@pytest.fixture
def func(): ...
or as
@pytest.fixture()
def func(): ...
or (while maybe not intended)
func = pytest.fixture(func)
so it needs to inspect internally whether it got a function in the first
positional argument or not.
Previously, there were was oddity. In the following,
func = pytest.fixture(func, autouse=True)
# OR
func = pytest.fixture(func, parms=['a', 'b'])
The result is as if `func` wasn't passed.
There isn't any reason for this special that I can understand, so remove
it.
This function is exposed and kept alive for the oejskit plugin which is
abandoned and no longer works with recent plugins, so let's prepare to
completely remove it.
The dynamic scope feature added in 10bf6aac76
necessitated some wrangling of arguments in pytest.fixture(). In
particular, it deprecated positional arguments in favor of keyword-only
arguments, while keeping backward compatibility.
The way it did this avoided some code duplication but ended up being
quite hard to follow and to annotate with types.
Replace it with some straightforward code, which is not very DRY but is
simple and easy to remove when the time comes.
Everything was using `_pytest.compat.getfslineno` basically, which
wrapped `_pytest._code.source.getfslineno`.
This moves the extra code from there into it directly, and uses the
latter everywhere.
This helps to eventually remove the one in compat eventually, and also
causes less cyclic imports.
This allows for e.g. Jedi to infer types (it checks the name).
It was only used to support Python 3.5.0/3.5.1, where this is is not
available in the `typing` module.
Ref: https://github.com/davidhalter/jedi/issues/1472
Uses `TYPE_CHECKING = False` in `_pytest.outcomes` to avoid having to
work around circular import.