`TypeMapping` is no longer cow-shaped.
Before, `TypeMapping` defined a `to_owned` method, which would make an
owned copy of the type mapping. This let us apply type mappings to
function literals lazily. The primary part of a function that you have
to apply the type mapping to is its signature. The hypothesis was that
doing this lazily would prevent us from constructing the signature of a
function just to apply a type mapping; if you never ended up needed the
updated function signature, that would be extraneous work.
But looking at the CI for this PR, it looks like that hypothesis is
wrong! And this definitely cleans up the code quite a bit. It also means
that over time we can consider replacing all of these `TypeMapping` enum
variants with separate `TypeTransformer` impls.
---------
Co-authored-by: David Peter <mail@david-peter.de>
## Summary
Fixes a bug observed by @AlexWaygood where `C[Any] <: C[object]` should
hold for a class that is covariant in its type parameter (and similar
subtyping relations involving dynamic types for other variance
configurations).
## Test Plan
New and updated Markdown tests
While working on #20093, I kept running into test failures due to
constraint sets not simplifying as much as they could, and therefore not
being easily testable against "always true" and "always false".
This PR updates our constraint set representation to use BDDs. Because
BDDs are reduced and ordered, they are canonical — equivalent boolean
formulas are represented by the same interned BDD node.
That said, there is a wrinkle, in that the "variables" that we use in
these BDDs — the individual constraints like `Lower ≤ T ≤ Upper` are not
always independent of each other.
As an example, given types `A ≤ B ≤ C ≤ D` and a typevar `T`, the
constraints `A ≤ T ≤ C` and `B ≤ T ≤ D` "overlap" — their intersection
is non-empty. So we should be able to simplify
```
(A ≤ T ≤ C) ∧ (B ≤ T ≤ D) == (B ≤ T ≤ C)
```
That's not a simplification that the BDD structure can perform itself,
since those three constraints are modeled as separate BDD variables, and
are therefore "opaque" to the BDD algorithms.
That means we need to perform this kind of simplification ourselves. We
look at pairs of constraints that appear in a BDD and see if they can be
simplified relative to each other, and if so, replace the pair with the
simplification. A large part of the toil of getting this PR to work was
identifying all of those patterns and getting that substitution logic
correct.
With this new representation, all existing tests pass, as well as some
new ones that represent test failures that were occuring on #20093.
---------
Co-authored-by: Carl Meyer <carl@astral.sh>
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## Summary
Follow up on #20495. The improvement suggested by @AlexWaygood cannot be
applied as-is since the `argument_matches` vector is indexed by argument
number, while the two boolean vectors are indexed by parameter number.
Still coalescing the latter two saves one allocation.
## Summary
Closes: https://github.com/astral-sh/ty/issues/551
This PR adds support for step 4 of the overload call evaluation
algorithm which states that:
> If the argument list is compatible with two or more overloads,
determine whether one or more of the overloads has a variadic parameter
(either `*args` or `**kwargs`) that maps to a corresponding argument
that supplies an indeterminate number of positional or keyword
arguments. If so, eliminate overloads that do not have a variadic
parameter.
And, with that, the overload call evaluation algorithm has been
implemented completely end to end as stated in the typing spec.
## Test Plan
Expand the overload call test suite.
## Summary
This removes a hack in the protocol satisfiability check that was
previously needed to work around missing assignability-modeling of
inferable type variables. Assignability of type variables is not
implemented fully, but some recent changes allow us to remove that hack
with limited impact on the ecosystem (and the test suite). The change in
the typing conformance test is favorable.
## Test Plan
* Adapted Markdown tests
* Made sure that this change works in combination with
https://github.com/astral-sh/ruff/pull/20517
## Summary
Closes: https://github.com/astral-sh/ty/issues/1236
This PR fixes a bug where the variadic argument wouldn't match against
the variadic parameter in certain scenarios.
This was happening because I didn't realize that the `all_elements`
iterator wouldn't keep on returning the variable element (which is
correct, I just didn't realize it back then).
I don't think we can use the `resize` method here because we don't know
how many parameters this variadic argument is matching against as this
is where the actual parameter matching occurs.
## Test Plan
Expand test cases to consider a few more combinations of arguments and
parameters which are variadic.
## Summary
This applies the trick that we use for `builtins.open` to similar
functions that have the same problem. The reason is that the problem
would otherwise become even more pronounced once we add understanding of
the implicit type of `self` parameters, because then something like
`(base_path / "test.bin").open("rb")` also leads to a wrong return type
and can result in false positives.
## Test Plan
New Markdown tests
## Summary
I found this bug while working on #20528.
The minimum reproducible code is:
```python
from __future__ import annotations
from typing import NamedTuple
from ty_extensions import is_disjoint_from, static_assert
class Path(NamedTuple):
prev: Path | None
key: str
static_assert(not is_disjoint_from(Path, Path))
```
A stack overflow occurs when a nominal instance type inherits from
`NamedTuple` and is defined recursively.
This PR fixes this bug.
## Test Plan
mdtest updated
### Summary
This PR includes two changes, both of which are necessary to resolve
https://github.com/astral-sh/ty/issues/1196:
* For a generic class `C[T]`, we previously used `C[Unknown]` as the
upper bound of the `Self` type variable. There were two problems with
this. For one, when `Self` appeared in contravariant position, we would
materialize its upper bound to `Bottom[C[Unknown]]` (which might
simplify to `C[Never]` if `C` is covariant in `T`) when accessing
methods on `Top[C[Unknown]]`. This would result in `invalid-argument`
errors on the `self` parameter. Also, using an upper bound of
`C[Unknown]` would mean that inside methods, references to `T` would be
treated as `Unknown`. This could lead to false negatives. To fix this,
we now use `C[T]` (with a "nested" typevar) as the upper bound for
`Self` on `C[T]`.
* In order to make this work, we needed to allow assignability/subtyping
of inferable typevars to other types, since we now check assignability
of e.g. `C[int]` to `C[T]` (when checking assignability to the upper
bound of `Self`) when calling an instance-method on `C[int]` whose
`self` parameter is annotated as `self: Self` (or implicitly `Self`,
following https://github.com/astral-sh/ruff/pull/18007).
closes https://github.com/astral-sh/ty/issues/1196
closes https://github.com/astral-sh/ty/issues/1208
### Test Plan
Regression tests for both issues.
## Summary
@ibraheemdev notes this example failed
```py
from typing import Callable
class X:
...
def f(callable: Callable[[], X]) -> X:
return callable()
x = f(X)
```
Resolves https://github.com/astral-sh/ty/issues/1210
The issue was that we set the `Self` to the class type instead of the
instance type of the class.
## Test Plan
Fix tests in `is_subtype_of.md`
## Summary
Fixes https://github.com/astral-sh/ty/issues/1218.
This bug doesn't currently cause us any real-world issues, because we
don't yet understand the signatures typeshed gives us for `isinstance()`
and `issubclass()` (typeshed's annotations there use PEP-613 type
aliases). #20107 demonstrates that this will start causing us issues as
soon as we add support for PEP-613 aliases, however, so it makes sense
to fix it now.
## Test Plan
Added mdtests
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Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>
Co-authored-by: Micha Reiser <micha@reiser.io>
Co-authored-by: David Peter <mail@david-peter.de>
Co-authored-by: Ibraheem Ahmed <ibraheem@ibraheem.ca>
## Summary
This PR adds support for unpacking `**kwargs` argument.
This can be matched against any standard (positional or keyword),
keyword-only, or keyword variadic parameter that haven't been matched
yet.
This PR also takes care of special casing `TypedDict` because the key
names and the corresponding value type is known, so we can be more
precise in our matching and type checking step. In the future, this
special casing would be extended to include `ParamSpec` as well.
Part of astral-sh/ty#247
## Test Plan
Add test cases for various scenarios.
## Summary
This change reduces MD test compilation time from 6s to 3s on my laptop.
We don't need to build the unit tests and the corpus tests when we're
only interested in Markdown-based tests.
## Test Plan
local benchmarks
## Summary
Part of https://github.com/astral-sh/ty/issues/168. Infer more precise types for collection literals (currently, only `list` and `set`). For example,
```py
x = [1, 2, 3] # revealed: list[Unknown | int]
y: list[int] = [1, 2, 3] # revealed: list[int]
```
This could easily be extended to `dict` literals, but I am intentionally limiting scope for now.
Fixes: https://github.com/astral-sh/ty/issues/1173
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## Summary
This PR will change the logic of binding Self type variables to bind
self to the immediate function that it's used on.
Since we are binding `self` to methods and not the class itself we need
to ensure that we bind self consistently.
The fix is to traverse scopes containing the self and find the first
function inside a class and use that function to bind the typevar for
self.
If no such scope is found we fallback to the normal behavior. Using Self
outside of a class scope is not legal anyway.
## Test Plan
Added a new mdtest.
Checked the diagnostics that are not emitted anymore in [primer
results](https://github.com/astral-sh/ruff/pull/20366#issuecomment-3289411424).
It looks good altough I don't completely understand what was wrong
before.
---------
Co-authored-by: Douglas Creager <dcreager@dcreager.net>
This is somewhat inspired by a similar abstraction in
`ruff_linter`. The main idea is to create an importer once
for a module that you want to add imports to. And then call
`import` to generate an edit for each symbol you want to
add.
I haven't done any performance profiling here yet. I don't
know if it will be a bottleneck. In particular, I do expect
`Importer::import` (but not `Importer::new`) to get called
many times for a single completion request when auto-import
is enabled. Particularly in projects with a lot of unimported
symbols. Because I don't know the perf impact, I didn't do
any premature optimization here. But there are surely some
low hanging fruit if this does prove to be a problem.
New tests make up a big portion of the diff here. I tried to
think of a bunch of different cases, although I'm sure there
are more.
I think this is a better home for it. This way, `ty_ide`
more clearly owns how the "kind" of a completion is computed.
In particular, it is computed differently for things where
we know its type versus unimported symbols.
In the course of writing the "add an import" implementation,
I realized that we needed to know which symbols were in scope
and how they were defined. This was necessary to be able to
determine how to add a new import in a way that (minimally)
does not conflict with existing symbols.
I'm not sure that this is fully correct (especially for
symbol bindings) and it's unclear to me in which cases a
definition site will be missing. But this seems to work for
some of the basic cases that I tried.
The names of the submodules returned should be *complete*. This
is the contract of `Module::name`. However, we were previously
only returning the basename of the submodule.
## Summary
Catch infinite recursion in binary-compare inference.
Fixes the stack overflow in `graphql-core` in mypy-primer.
## Test Plan
Added two tests that stack-overflowed before this PR.
## Summary
Use `Type::Divergent` to short-circuit diverging types in type
expressions. This avoids panicking in a wide variety of cases of
recursive type expressions.
Avoids many panics (but not yet all -- I'll be tracking down the rest)
from https://github.com/astral-sh/ty/issues/256 by falling back to
Divergent. For many of these recursive type aliases, we'd like to
support them properly (i.e. really understand the recursive nature of
the type, not just fall back to Divergent) but that will be future work.
This switches `Type::has_divergent_type` from using `any_over_type` to a
custom set of visit methods, because `any_over_type` visits more than we
need to visit, and exercises some lazy attributes of type, causing
significantly more work. This change means this diff doesn't regress
perf; it even reclaims some of the perf regression from
https://github.com/astral-sh/ruff/pull/20333.
## Test Plan
Added mdtest for recursive type alias that panics on main.
Verified that we can now type-check `packaging` (and projects depending
on it) without panic; this will allow moving a number of mypy-primer
projects from `bad.txt` to `good.txt` in a subsequent PR.
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## Summary
This PR implements F406
https://docs.astral.sh/ruff/rules/undefined-local-with-nested-import-star-usage/
as a semantic syntax error
## Test Plan
I have written inline tests as directed in #17412
---------
Signed-off-by: 11happy <soni5happy@gmail.com>
Previously, we used a very fine-grained representation for individual
constraints: each constraint was _either_ a range constraint, a
not-equivalent constraint, or an incomparable constraint. These three
pieces are enough to represent all of the "real" constraints we need to
create — range constraints and their negation.
However, it meant that we weren't picking up as many chances to simplify
constraint sets as we could. Our simplification logic depends on being
able to look at _pairs_ of constraints or clauses to see if they
simplify relative to each other. With our fine-grained representation,
we could easily encounter situations that we should have been able to
simplify, but that would require looking at three or more individual
constraints.
For instance, negating a range constraint would produce:
```
¬(Base ≤ T ≤ Super) = ((T ≤ Base) ∧ (T ≠ Base)) ∨ (T ≁ Base) ∨
((Super ≤ T) ∧ (T ≠ Super)) ∨ (T ≁ Super)
```
That is, `T` must be (strictly) less than `Base`, (strictly) greater
than `Super`, or incomparable to either.
If we tried to union those back together, we should get `always`, since
`x ∨ ¬x` should always be true, no matter what `x` is. But instead we
would get:
```
(Base ≤ T ≤ Super) ∨ ((T ≤ Base) ∧ (T ≠ Base)) ∨ (T ≁ Base) ∨ ((Super ≤ T) ∧ (T ≠
Super)) ∨ (T ≁ Super)
```
Nothing would simplify relative to each other, because we'd have to look
at all five union elements to see that together they do in fact combine
to `always`.
The fine-grained representation was nice, because it made it easier to
[work out the math](https://dcreager.net/theory/constraints/) for
intersections and unions of each kind of constraint. But being able to
simplify is more important, since the example above comes up immediately
in #20093 when trying to handle constrained typevars.
The fix in this PR is to go back to a more coarse-grained
representation, where each individual constraint consists of a positive
range (which might be `always` / `Never ≤ T ≤ object`), and zero or more
negative ranges. The intuition is to think of a constraint as a region
of the type space (representable as a range) with zero or more "holes"
removed from it.
With this representation, negating a range constraint produces:
```
¬(Base ≤ T ≤ Super) = (always ∧ ¬(Base ≤ T ≤ Super))
```
(That looks trivial, because it is! We just move the positive range to
the negative side.)
The math is not that much harder than before, because there are only
three combinations to consider (each for intersection and union) —
though the fact that there can be multiple holes in a constraint does
require some nested loops. But the mdtest suite gives me confidence that
this is not introducing any new issues, and it definitely removes a
troublesome TODO.
(As an aside, this change also means that we are back to having each
clause contain no more than one individual constraint for any typevar.
This turned out to be important, because part of our simplification
logic was also depending on that!)
---------
Co-authored-by: Carl Meyer <carl@astral.sh>
## Summary
This mainly removes an internal inconsistency, where we didn't remove
the `Self` type variable when eagerly binding `Self` to an instance
type. It has no observable effect, apparently.
builds on top of https://github.com/astral-sh/ruff/pull/20328
## Test Plan
None
## Summary
Fixes https://github.com/astral-sh/ty/issues/1161
Include `NamedTupleFallback` members in `NamedTuple` instance
completions.
- Augment instance attribute completions when completing on NamedTuple
instances by merging members from
`_typeshed._type_checker_internals.NamedTupleFallback`
## Test Plan
Adds a minimal completion test `namedtuple_fallback_instance_methods`
---------
Co-authored-by: David Peter <mail@david-peter.de>
## Summary
This project was [recently removed from
mypy_primer](https://github.com/astral-sh/ruff/pull/20378), so we need
to remove it from `good.txt` in order for ecosystem-analyzer to work
correctly.
## Test Plan
Run mypy_primer and ecosystem-analyzer on this branch.
## Summary
https://github.com/astral-sh/ruff/pull/20165 added a lot of false
positives around calls to `builtins.open()`, because our missing support
for PEP-613 type aliases means that we don't understand typeshed's
overloads for `builtins.open()` at all yet, and therefore always select
the first overload. This didn't use to matter very much, but now that we
have a much stricter implementation of protocol assignability/subtyping
it matters a lot, because most of the stdlib functions dealing with I/O
(`pickle`, `marshal`, `io`, `json`, etc.) are annotated in typeshed as
taking in protocols of some kind.
In lieu of full PEP-613 support, which is blocked on various things and
might not land in time for our next alpha release, this PR adds some
temporary special-casing for `builtins.open()` to avoid the false
positives. We just infer `Todo` for anything that isn't meant to match
typeshed's first `open()` overload. This should be easy to rip out again
once we have proper support for PEP-613 type aliases, which hopefully
should be pretty soon!
## Test Plan
Added an mdtest
## Summary
Fixes https://github.com/astral-sh/ty/issues/377.
We were treating any function as being assignable to any callback
protocol, because we were trying to figure out a type's `Callable`
supertype by looking up the `__call__` attribute on the type's
meta-type. But a function-literal's meta-type is `types.FunctionType`,
and `types.FunctionType.__call__` is `(...) -> Any`, which is not very
helpful!
While working on this PR, I also realised that assignability between
class-literals and callback protocols was somewhat broken too, so I
fixed that at the same time.
## Test Plan
Added mdtests
## Summary
This looks like it should fix the errors that we've been seeing in sympy
in recent mypy-primer runs.
## Test Plan
I wasn't able to reproduce the sympy failures locally; it looks like
there is probably a dependency on the order in which files are checked.
So I don't have a minimal reproducible example, and wasn't able to add a
test :/ Obviously I would be happier if we could commit a regression
test here, but since the change is straightforward and clearly
desirable, I'm not sure how many hours it's worth trying to track it
down.
Mypy-primer is still failing in CI on this PR, because it fails on the
"old" ty commit already (i.e. on main). But it passes [on a no-op PR
stacked on top of this](https://github.com/astral-sh/ruff/pull/20370),
which strongly suggests this PR fixes the problem.
## Summary
This PR addresses an issue for a variadic argument when involved in
argument type expansion of overload call evaluation.
The issue is that the expansion of the variadic argument could result in
argument list of different arity. For example, in `*args: tuple[int] |
tuple[int, str]`, the expansion would lead to the variadic argument
being unpacked into 1 and 2 element respectively. This means that the
parameter matching that was performed initially isn't sufficient and
each expanded argument list would need to redo the parameter matching
again.
This is currently done by redoing the parameter matching directly,
maintaining the state of argument forms (and the conflicting forms), and
updating the `Bindings` values if it changes.
Closes: astral-sh/ty#735
## Test Plan
Update existing mdtest.
This PR removes the `Constraints` trait. We removed the `bool`
implementation several weeks back, and are using `ConstraintSet`
everywhere. There have been discussions about trying to include the
reason for an assignability failure as part of the result, but that
there are no concrete plans to do so soon, and it's not clear that we'll
need the `Constraints` trait to do that. (We can ideally just update the
`ConstraintSet` type directly.)
In the meantime, this just complicates the code for no good reason.
This PR is a pure refactoring, and contains no behavioral changes.
---------
Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>
Previously, `Type::object` would find the definition of the `object`
class in typeshed, load that in (to produce a `ClassLiteral` and
`ClassType`), and then create a `NominalInstance` of that class.
It's possible that we are using a typeshed that doesn't define `object`.
We will not be able to do much useful work with that kind of typeshed,
but it's still a possibility that we have to support at least without
panicking. Previously, we would handle this situation by falling back on
`Unknown`.
In most cases, that's a perfectly fine fallback! But `object` is also
our top type — the type of all values. `Unknown` is _not_ an acceptable
stand-in for the top type.
This PR adds a new `NominalInstance` variant for "instances of
`object`". Unlike other nominal instances, we do not need to load in
`object`'s `ClassType` to instantiate this variant. We will use this new
variant even when the current typeshed does not define an `object`
class, ensuring that we have a fully static representation of our top
type at all times.
There are several operations that need access to a nominal instance's
class, and for this new `object` variant we load it lazily only when
it's needed. That means this operation is now fallible, since this is
where the "typeshed doesn't define `object`" failure shows up.
This new approach also has the benefit of avoiding some salsa cycles
that were cropping up while I was debugging #20093, since the new
constraint set representation was trying to instantiate `Type::object`
while in the middle of processing its definition in typeshed. Cycle
handling was kicking in correctly and returning the `Unknown` fallback
mentioned above. But the constraint set implementation depends on
`Type::object` being a distinct and fully static type, highlighting that
this is a correctness fix, not just an optimization fix.
---------
Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>
## Summary
Use `Type::Divergent` to avoid "too many iterations" panic on an
infinitely-nested tuple in an implicit instance attribute.
The regression here is from checking all tuple elements to see if they
contain a Divergent type. It's 5% on one project, 1% on another, and
zero on the rest. I spent some time looking into eliminating this
regression by tracking a flag on inference results to note if they could
possibly contain any Divergent type, but this doesn't really work --
there are too many different ways a type containing a Divergent type
could enter an inference result. Still thinking about whether there are
other ways to reduce this. One option is if we see certain kinds of
non-atomic types that are commonly expensive to check for Divergent, we
could make `has_divergent_type` a Salsa query on those types.
## Test Plan
Added mdtest.
Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>
The debug representation isn't as useful as calling `.display(db)`, but
it's still kind-of annoying when `dbg!()` calls don't compile locally
due to the compiler not being able to guarantee that an object of type
`impl Constraints` implements `Debug`
## Summary
`CallableTypeOf[bound_method]` would previously bind `self` to the
bound method type itself, instead of binding it to the instance type
stored inside the bound method type.
## Test Plan
Added regression test
This PR adds a new `ty_extensions.ConstraintSet` class, which is used to
expose constraint sets to our mdtest framework. This lets us write a
large collection of unit tests that exercise the invariants and rewrite
rules of our constraint set implementation.
As part of this, `is_assignable_to` and friends are updated to return a
`ConstraintSet` instead of a `bool`, and we implement
`ConstraintSet.__bool__` to return when a constraint set is always
satisfied. That lets us still use
`static_assert(is_assignable_to(...))`, since the assertion will coerce
the constraint set to a bool, and also lets us
`reveal_type(is_assignable_to(...))` to see more detail about
whether/when the two types are assignable. That lets us get rid of
`reveal_when_assignable_to` and friends, since they are now redundant
with the expanded capabilities of `is_assignable_to`.
## Summary
When adding an enum literal `E = Literal[Color.RED]` to a union which
already contained a subtype of that enum literal(!), we were previously
not simplifying the union correctly. My assumption is that our property
tests didn't catch that earlier, because the only possible non-trivial
subytpe of an enum literal that I can think of is `Any & E`. And in
order for that to be detected by the property tests, it would have to
randomly generate `Any & E | E` and then also compare that with `E` on
the other side (in an equivalence test, or the subtyping-antisymmetry
test).
closes https://github.com/astral-sh/ty/issues/1155
## Test Plan
* Added a regression test.
* I also ran the property tests for a while, but probably not for two
months worth of daily CI runs.
The constraint representation that we added in #19997 was subtly wrong,
in that it didn't correctly model that type assignability is a _partial_
order — it's possible for two types to be incomparable, with neither a
subtype of the other. That means the negation of a constraint like `T ≤
t` (typevar `T` must be a subtype of `t`) is **_not_** `t < T`, but
rather `t < T ∨ T ≁ t` (using ≁ to mean "not comparable to").
That means we need to update our constraint representation to be an
enum, so that we can track both _range_ constraints (upper/lower bound
on the typevar), and these new _incomparable_ constraints.
Since we need an enum now, that also lets us simplify how we were
modeling range constraints. Before, we let the lower/upper bounds be
either open (<) or closed (≤). Now, range constraints are always closed,
and we add a third kind of constraint for _not equivalent_ (≠). We can
translate an open upper bound `T < t` into `T ≤ t ∧ T ≠ t`.
We already had the logic for doing adding _clauses_ to a _set_ by doing
a pairwise simplification. We copy that over to where we add
_constraints_ to a _clause_. To calculate the intersection or union of
two constraints, the new enum representation makes it easy to break down
all of the possibilities into a small number of cases: intersect range
with range, intersect range with not-equivalent, etc. I've done the math
[here](https://dcreager.net/theory/constraints/) to show that the
simplifications for each of these cases is correct.
## Summary
This is a follow-up to https://github.com/astral-sh/ruff/pull/19321.
Now lazy snapshots are updated to take into account new bindings on
every symbol reassignment.
```python
def outer(x: A | None):
if x is None:
x = A()
reveal_type(x) # revealed: A
def inner() -> None:
# lazy snapshot: {x: A}
reveal_type(x) # revealed: A
inner()
def outer() -> None:
x = None
x = 1
def inner() -> None:
# lazy snapshot: {x: Literal[1]} -> {x: Literal[1, 2]}
reveal_type(x) # revealed: Literal[1, 2]
inner()
x = 2
```
Closesastral-sh/ty#559.
## Test Plan
Some TODOs in `public_types.md` now work properly.
---------
Co-authored-by: Carl Meyer <carl@astral.sh>
## Summary
Adds support for generic PEP695 type aliases, e.g.,
```python
type A[T] = T
reveal_type(A[int]) # A[int]
```
Resolves https://github.com/astral-sh/ty/issues/677.
## Summary
Support cases like the following, where we need the generic context to
include both `Self` and `T` (not just `T`):
```py
from typing import Self
class C:
def method[T](self: Self, arg: T): ...
C().method(1)
```
closes https://github.com/astral-sh/ty/issues/1131
## Test Plan
Added regression test
## Summary
The sub-checks for assignability and subtyping of materializations
performed in `has_relation_in_invariant_position` and
`is_subtype_in_invariant_position` need to propagate the
`HasRelationToVisitor`, or we can stack overflow.
A side effect of this change is that we also propagate the
`ConstraintSet` through, rather than using `C::from_bool`, which I think
may also become important for correctness in cases involving type
variables (though it isn't testable yet, since we aren't yet actually
creating constraints other than always-true and always-false.)
## Test Plan
Added mdtest (derived from code found in pydantic) which
stack-overflowed before this PR.
With this change incorporated, pydantic now checks successfully on my
draft PR for PEP 613 TypeAlias support.
Now that https://github.com/astral-sh/ruff/pull/20263 is merged, we can
update mypy_primer and add the new `egglog-python` project to
`good.txt`. The ecosystem-analyzer run shows that we now add 1,356
diagnostics (where we had over 5,000 previously, due to the unsupported
project layout).
## Summary
Add backreferences to the original item declaration in TypedDict
diagnostics.
Thanks to @AlexWaygood for the suggestion.
## Test Plan
Updated snapshots
## Summary
An annotated assignment `name: annotation` without a right-hand side was
previously not covered by the range returned from
`DefinitionKind::full_range`, because we did expand the range to include
the right-hand side (if there was one), but failed to include the
annotation.
## Test Plan
Updated snapshot tests
## Summary
Add support for `typing.ReadOnly` as a type qualifier to mark
`TypedDict` fields as being read-only. If you try to mutate them, you
get a new diagnostic:
<img width="787" height="234" alt="image"
src="https://github.com/user-attachments/assets/f62fddf9-4961-4bcd-ad1c-747043ebe5ff"
/>
## Test Plan
* New Markdown tests
* The typing conformance changes are all correct. There are some false
negatives, but those are related to the missing support for the
functional form of `TypedDict`, or to overriding of fields via
inheritance. Both of these topics are tracked in
https://github.com/astral-sh/ty/issues/154
Alex Waygood
Douglas Creager
Takayuki Maeda
David Peter
Francesco Giacometti
Dhruv Manilawala
Aria Desires
Ibraheem Ahmed
Shunsuke Shibayama
Renkai Ge
Dan Parizher
justin
Matthew Mckee
Micha Reiser
GF
renovate[bot]
Eric Mark Martin
Shaygan Hooshyari
Andrew Gallant
Carl Meyer
Bhuminjay Soni