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.
An upcoming commit wants to import from `_pytest.pytester` in the public
`pytest` module. This means that `_pytest.pytester` would start to get
imported during import time, which it hasn't up to now -- it was
imported by the plugin loader (if requested). When a plugin is loaded,
it is subjected to assertion rewriting, but only if the module isn't
imported yet, it issues a warning "Module already imported so cannot be
rewritten" and skips the rewriting. So we'd end up with the pytester
plugin not being rewritten, but it wants to be.
Absent better ideas, the solution here is to split the pytester
assertions to their own plugin (which will always only be imported by
the plugin loader) and exclude pytester itself from plugin rewriting.
Don't import `pytest` from within some `_pytest` modules since an
upcoming commit will import from them into `pytest`.
It would have been nice not to have to do it, so that internal plugins
look more like external plugins, but with the existing layout this seems
unavoidable.
In pytester tests, pytest stashes & restores the sys.modules for each
test. So if the test imports a new module, it is initialized anew each
time.
Turns out the readline module isn't multi-init safe, which causes
pytester.spawn to crash or hang. So preserve it as a workaround.
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 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.
_pytest.timing is an indirection to 'time' functions, which pytest production
code should use instead of 'time' directly.
'mock_timing' is a new fixture which then mocks those functions, allowing us
to write time-reliable tests which run instantly and are not flaky.
This was triggered by recent flaky junitxml tests on Windows related to timing
issues.
When using `(i)var` in the class docstring it would link `duration` to
`_pytest.runner.TestReport.duration`.
This moves the docstrings to the attributes properly.
ExitCode is used in several internal modules and hooks and so with type
annotations added, needs to be imported a lot.
_pytest.main, being the entry point, generally sits at the top of the
import tree.
So, it's not great to have ExitCode defined in _pytest.main, because it
will cause a lot of import cycles once type annotations are added (in
fact there is already one, which this change removes).
Move it to _pytest.config instead.
_pytest.main still imports ExitCode, so importing from there still
works, although external users should really be importing from `pytest`.
Without restoring the cwd, successive tests might fail to parse the
config (via `_pytest.config._prepareconfig()`, for when `--lsof` is
used).
And it is good practice to restore the cwd in any case anyway.
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.
This fixes some type: ignores due to typeshed update.
Newer mypy seem to ignore unannotated functions better, so add a few
minor annotations so that existing correct type:ignores make sense.
Sets `PY_COLORS=0` in the environment by default, which is used by pylib.
Via https://github.com/blueyed/pytest/pull/58
(initially cherry picked from commit f153ad33d10)