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.
Inline `_makeitem()` so that `self.ihook` (which is moderately
expensive) can be called only once.
Note: the removed test "test_makeitem_non_underscore" comes from an old
behavior of skipping names that start with `_` which has since been
generalized, making the test no longer relevant.
When a Python object (module/class/instance) is collected, for each name
in `obj.__dict__` (and up its MRO) the pytest_pycollect_makeitem hook is
called for potentially creating a node for it.
These Python objects have a bunch of builtin attributes that are
extremely unlikely to be collected. But due to their pervasiveness,
dispatching the hook for them ends up being mildly expensive and also
pollutes PYTEST_DEBUG=1 output and such.
Let's just ignore these attributes.
On the pandas test suite commit 04e9e0afd476b1b8bed930e47bf60e,
collect only, irrelevant lines snipped, about 5% improvement:
Before:
```
51195095 function calls (48844352 primitive calls) in 39.089 seconds
ncalls tottime percall cumtime percall filename:lineno(function)
226602/54 0.145 0.000 38.940 0.721 manager.py:90(_hookexec)
72227 0.285 0.000 20.146 0.000 python.py:424(_makeitem)
72227 0.171 0.000 16.678 0.000 python.py:218(pytest_pycollect_makeitem)
```
After:
```
48410921 function calls (46240870 primitive calls) in 36.950 seconds
ncalls tottime percall cumtime percall filename:lineno(function)
181429/54 0.113 0.000 36.777 0.681 manager.py:90(_hookexec)
27054 0.130 0.000 17.755 0.001 python.py:465(_makeitem)
27054 0.121 0.000 16.219 0.001 python.py:218(pytest_pycollect_makeitem)
```
In ff8b7884e8 NOTSET was changed to a
singleton enum, which ended up unexpectedly triggering a code path in ID
generation which checks for `isinstance(Enum)`.
Add an explicit case for it, which is not too bad anyway.
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.
In Python, if module A defines a name `name`, and module B does `import
name from A`, then another module C can `import name from B`.
Sometimes it is intentional -- module B is meant to "reexport" `name`.
But sometimes it is just confusion/inconsistency on where `name` should
be imported from.
mypy has a flag `--no-implicit-reexport` which puts some order into
this. A name can only be imported from a module if
1. The module defines the name
2. The module's `__all__` includes the name
3. The module imports the name as `from ... import .. as name`.
This flag is included in mypy's `--strict` flag.
I like this flag, but I realize it is a bit controversial, and in
particular item 3 above is a bit unfriendly to contributors who don't
know about it. So I didn't intend to add it to pytest.
But while investigating issue 7589 I came upon mypy issue 8754 which
causes `--no-implicit-reexport` to leak into installed libraries and
causes some unexpected typing differences *in pytest* if the user uses
this flag.
Since the diff mostly makes sense, let's just conform to it.
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`.
Part of reducing dependency on `py`. Also enables upcoming improvements.
In cases where there are simpler alternatives (in tests), I used those.
What's left are a couple of uses in `_pytest.main` and `_pytest.python`
and they only have modest requirements, so all of the featureful code
from py is not needed.
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.