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 is a follow up to 3f8200676f which didn't
make it clear that log_print is also removed in the changelog and didn't remove
it from the reference docs.
There are some ones we *would* like to enforce, like
D401 First line should be in imperative mood
but have too many false positives, so I left them out.
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 the effort to reduce dependency on the py library.
Besides that, py.xml implements its own XML serialization which is
pretty scary.
I tried to keep the code with minimal changes (though it could use some
cleanups). The differences in behavior I have noticed are:
- Attributes in the output are not sorted.
- Some unneeded escaping is no longer performed, for example escaping
`"` to `"` in a text node.
Bruno Oliveira
Ran Benita
Florian Bruhin
Anthony Sottile
C. Titus Brown
Hugo van Kemenade
Mattreex