## Summary
This is to support https://github.com/astral-sh/ruff/pull/18607.
This PR adds support for generating the top materialization (or upper
bound materialization) and the bottom materialization (or lower bound
materialization) of a type. This is the most general and the most
specific form of the type which is fully static, respectively.
More concretely, `T'`, the top materialization of `T`, is the type `T`
with all occurrences
of dynamic type (`Any`, `Unknown`, `@Todo`) replaced as follows:
- In covariant position, it's replaced with `object`
- In contravariant position, it's replaced with `Never`
- In invariant position, it's replaced with an unresolved type variable
(For an invariant position, it should actually be replaced with an
existential type, but this is not currently representable in our type
system, so we use an unresolved type variable for now instead.)
The bottom materialization is implemented in the same way, except we
start out in "contravariant" position.
## Test Plan
Add test cases for various types.
## Summary
Minor documentation update to make `mypy_primer` instructions a bit more
verbose/helpful for running against a local branch
## Test Plan
N/A
This makes it work for a number of additional cases, like nested
attribute access and things like `[].<CURSOR>`.
The basic idea is that instead of selecting a covering node closest to a
leaf that contains the cursor, we walk up the tree as much as we can.
This lets us access the correct `ExprAttribute` node when performing
nested access.
This routine lets us climb up the AST tree when we find
a contiguous sequence of nodes that satisfy our predicate.
This will be useful for making things like `a.b.<CURSOR>`
work. That is, we don't want the `ExprAttribute` closest
to a leaf. We also don't always want the `ExprAttribute`
closest to the root. Rather, (I think) we want the
`ExprAttribute` closest to the root that has an unbroken
chain to the `ExprAttribute` closest to the leaf.
This commit doesn't change any functionality, but instead changes the
representation of `CoveringNode` to make the implementation simpler (as
well as planned future additions). By putting the found node last in the
list of ancestors (now just generically called `nodes`), we reduce the
amount of special case handling we need.
The downside is that the representation now allows invalid states (a
`CoveringNode` with no elements). But I think this is well mitigated by
encapsulation.
## Summary
Fixes https://github.com/astral-sh/ty/issues/557
## Test Plan
Stable property tests succeed with a million iterations. Added mdtests.
---------
Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>
Summary
--
Updates the rule docs to explicitly state how cases like
`Decimal("0.1")` are handled (not affected) because the discussion of
"float casts" referring to values like `nan` and `inf` is otherwise a
bit confusing.
These changes are based on suggestions from @AlexWaygood on Notion, with
a slight adjustment to use 0.1 instead of 0.5 since it causes a more
immediate issue in the REPL:
```pycon
>>> from decimal import Decimal
>>> Decimal(0.5) == Decimal("0.5")
True
>>> Decimal(0.1) == Decimal("0.1")
False
```
Test plan
--
N/a
Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>
Summary
--
This PR updates the docs for PLW1641 to place less emphasis on the
example of inheriting a parent class's `__hash__` implementation by both
reducing the length of the example and warning that it may be unsound in
general, as @AlexWaygood pointed out on Notion.
Test plan
--
Existing tests
---------
Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>
## Summary
Fixes https://github.com/astral-sh/ruff/issues/18602 by:
1. Avoiding a fix when `*args` are present
2. Inserting the `Generic` base class right before the first keyword
argument, if one is present
In an intermediate commit, I also had special handling to avoid a fix in
the `**kwargs` case, but this is treated (roughly) as a normal keyword,
and I believe handling it properly falls out of the other keyword fix.
I also updated the `add_argument` utility function to insert new
arguments right before the keyword argument list instead of at the very
end of the argument list. This changed a couple of snapshots unrelated
to `PYI059`, but there shouldn't be any functional changes to other
rules because all other calls to `add_argument` were adding a keyword
argument anyway.
## Test Plan
Existing PYI059 cases, plus new tests based on the issue
---------
Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>
## Summary
Closes https://github.com/astral-sh/ty/issues/577. Make global
`__debug__` a `bool` constant.
## Test Plan
Mdtest `global-constants.md` was created to check if resolved type was
`bool`.
---------
Co-authored-by: David Peter <mail@david-peter.de>
Summary
--
Fixes#18590 by adding parentheses around lambdas and if expressions in
`for` loop iterators for FURB122 and FURB142. I also updated the docs on
the helper function to reflect the part actually being parenthesized and
the new checks.
The `lambda` case actually causes a `TypeError` at runtime, but I think
it's still worth handling to avoid causing a syntax error.
```pycon
>>> s = set()
... for x in (1,) if True else (2,):
... s.add(-x)
... for x in lambda: 0:
... s.discard(-x)
...
Traceback (most recent call last):
File "<python-input-0>", line 4, in <module>
for x in lambda: 0:
^^^^^^^^^
TypeError: 'function' object is not iterable
```
Test Plan
--
New test cases based on the bug report
---------
Co-authored-by: Dylan <dylwil3@gmail.com>