## Summary
Add support for generic PEP 613 type aliases and generic implicit type
aliases:
```py
from typing import TypeVar
T = TypeVar("T")
ListOrSet = list[T] | set[T]
def _(xs: ListOrSet[int]):
reveal_type(xs) # list[int] | set[int]
```
closes https://github.com/astral-sh/ty/issues/1643
closes https://github.com/astral-sh/ty/issues/1629
closes https://github.com/astral-sh/ty/issues/1596
closes https://github.com/astral-sh/ty/issues/573
closes https://github.com/astral-sh/ty/issues/221
## Typing conformance
```diff
-aliases_explicit.py:52:5: error[type-assertion-failure] Type `list[int]` does not match asserted type `@Todo(specialized generic alias in type expression)`
-aliases_explicit.py:53:5: error[type-assertion-failure] Type `tuple[str, ...] | list[str]` does not match asserted type `@Todo(Generic specialization of types.UnionType)`
-aliases_explicit.py:54:5: error[type-assertion-failure] Type `tuple[int, int, int, str]` does not match asserted type `@Todo(specialized generic alias in type expression)`
-aliases_explicit.py:56:5: error[type-assertion-failure] Type `(int, str, /) -> str` does not match asserted type `@Todo(Generic specialization of typing.Callable)`
-aliases_explicit.py:59:5: error[type-assertion-failure] Type `int | str | None | list[list[int]]` does not match asserted type `int | str | None | list[@Todo(specialized generic alias in type expression)]`
```
New true negatives ✔️
```diff
+aliases_explicit.py:41:36: error[invalid-type-arguments] Too many type arguments: expected 1, got 2
-aliases_explicit.py:57:5: error[type-assertion-failure] Type `(int, str, str, /) -> None` does not match asserted type `@Todo(Generic specialization of typing.Callable)`
+aliases_explicit.py:57:5: error[type-assertion-failure] Type `(int, str, str, /) -> None` does not match asserted type `(...) -> Unknown`
```
These require `ParamSpec`
```diff
+aliases_explicit.py:67:24: error[invalid-type-arguments] Too many type arguments: expected 0, got 1
+aliases_explicit.py:68:24: error[invalid-type-arguments] Too many type arguments: expected 0, got 1
+aliases_explicit.py:69:29: error[invalid-type-arguments] Too many type arguments: expected 1, got 2
+aliases_explicit.py:70:29: error[invalid-type-arguments] Too many type arguments: expected 1, got 2
+aliases_explicit.py:71:29: error[invalid-type-arguments] Too many type arguments: expected 1, got 2
+aliases_explicit.py:102:20: error[invalid-type-arguments] Too many type arguments: expected 0, got 1
```
New true positives ✔️
```diff
-aliases_implicit.py:63:5: error[type-assertion-failure] Type `list[int]` does not match asserted type `@Todo(specialized generic alias in type expression)`
-aliases_implicit.py:64:5: error[type-assertion-failure] Type `tuple[str, ...] | list[str]` does not match asserted type `@Todo(Generic specialization of types.UnionType)`
-aliases_implicit.py:65:5: error[type-assertion-failure] Type `tuple[int, int, int, str]` does not match asserted type `@Todo(specialized generic alias in type expression)`
-aliases_implicit.py:67:5: error[type-assertion-failure] Type `(int, str, /) -> str` does not match asserted type `@Todo(Generic specialization of typing.Callable)`
-aliases_implicit.py:70:5: error[type-assertion-failure] Type `int | str | None | list[list[int]]` does not match asserted type `int | str | None | list[@Todo(specialized generic alias in type expression)]`
-aliases_implicit.py:71:5: error[type-assertion-failure] Type `list[bool]` does not match asserted type `@Todo(specialized generic alias in type expression)`
```
New true negatives ✔️
```diff
+aliases_implicit.py:54:36: error[invalid-type-arguments] Too many type arguments: expected 1, got 2
-aliases_implicit.py:68:5: error[type-assertion-failure] Type `(int, str, str, /) -> None` does not match asserted type `@Todo(Generic specialization of typing.Callable)`
+aliases_implicit.py:68:5: error[type-assertion-failure] Type `(int, str, str, /) -> None` does not match asserted type `(...) -> Unknown`
```
These require `ParamSpec`
```diff
+aliases_implicit.py:76:24: error[invalid-type-arguments] Too many type arguments: expected 0, got 1
+aliases_implicit.py:77:24: error[invalid-type-arguments] Too many type arguments: expected 0, got 1
+aliases_implicit.py:78:29: error[invalid-type-arguments] Too many type arguments: expected 1, got 2
+aliases_implicit.py:79:29: error[invalid-type-arguments] Too many type arguments: expected 1, got 2
+aliases_implicit.py:80:29: error[invalid-type-arguments] Too many type arguments: expected 1, got 2
+aliases_implicit.py:81:25: error[invalid-type-arguments] Type `str` is not assignable to upper bound `int | float` of type variable `TFloat@GoodTypeAlias12`
+aliases_implicit.py:135:20: error[invalid-type-arguments] Too many type arguments: expected 0, got 1
```
New true positives ✔️
```diff
+callables_annotation.py:172:19: error[invalid-type-arguments] Too many type arguments: expected 0, got 1
+callables_annotation.py:175:19: error[invalid-type-arguments] Too many type arguments: expected 0, got 1
+callables_annotation.py:188:25: error[invalid-type-arguments] Too many type arguments: expected 0, got 1
+callables_annotation.py:189:25: error[invalid-type-arguments] Too many type arguments: expected 0, got 1
```
These require `ParamSpec` and `Concatenate`.
```diff
-generics_defaults_specialization.py:26:5: error[type-assertion-failure] Type `SomethingWithNoDefaults[int, str]` does not match asserted type `SomethingWithNoDefaults[int, typing.TypeVar]`
+generics_defaults_specialization.py:26:5: error[type-assertion-failure] Type `SomethingWithNoDefaults[int, str]` does not match asserted type `SomethingWithNoDefaults[int, DefaultStrT]`
```
Favorable diagnostic change ✔️
```diff
-generics_defaults_specialization.py:27:5: error[type-assertion-failure] Type `SomethingWithNoDefaults[int, bool]` does not match asserted type `@Todo(specialized generic alias in type expression)`
```
New true negative ✔️
```diff
-generics_defaults_specialization.py:30:1: error[non-subscriptable] Cannot subscript object of type `<class 'SomethingWithNoDefaults[int, typing.TypeVar]'>` with no `__class_getitem__` method
+generics_defaults_specialization.py:30:15: error[invalid-type-arguments] Too many type arguments: expected between 0 and 1, got 2
```
Correct new diagnostic ✔️
```diff
-generics_variance.py:175:25: error[non-subscriptable] Cannot subscript object of type `<class 'Contra[typing.TypeVar]'>` with no `__class_getitem__` method
-generics_variance.py:175:35: error[non-subscriptable] Cannot subscript object of type `<class 'Co[typing.TypeVar]'>` with no `__class_getitem__` method
-generics_variance.py:179:29: error[non-subscriptable] Cannot subscript object of type `<class 'Contra[typing.TypeVar]'>` with no `__class_getitem__` method
-generics_variance.py:179:39: error[non-subscriptable] Cannot subscript object of type `<class 'Contra[typing.TypeVar]'>` with no `__class_getitem__` method
-generics_variance.py:183:21: error[non-subscriptable] Cannot subscript object of type `<class 'Co[typing.TypeVar]'>` with no `__class_getitem__` method
-generics_variance.py:183:27: error[non-subscriptable] Cannot subscript object of type `<class 'Co[typing.TypeVar]'>` with no `__class_getitem__` method
-generics_variance.py:187:25: error[non-subscriptable] Cannot subscript object of type `<class 'Co[typing.TypeVar]'>` with no `__class_getitem__` method
-generics_variance.py:187:31: error[non-subscriptable] Cannot subscript object of type `<class 'Contra[typing.TypeVar]'>` with no `__class_getitem__` method
-generics_variance.py:191:33: error[non-subscriptable] Cannot subscript object of type `<class 'Contra[typing.TypeVar]'>` with no `__class_getitem__` method
-generics_variance.py:191:43: error[non-subscriptable] Cannot subscript object of type `<class 'Co[typing.TypeVar]'>` with no `__class_getitem__` method
-generics_variance.py:191:49: error[non-subscriptable] Cannot subscript object of type `<class 'Contra[typing.TypeVar]'>` with no `__class_getitem__` method
-generics_variance.py:196:5: error[non-subscriptable] Cannot subscript object of type `<class 'Contra[typing.TypeVar]'>` with no `__class_getitem__` method
-generics_variance.py:196:15: error[non-subscriptable] Cannot subscript object of type `<class 'Contra[typing.TypeVar]'>` with no `__class_getitem__` method
-generics_variance.py:196:25: error[non-subscriptable] Cannot subscript object of type `<class 'Contra[typing.TypeVar]'>` with no `__class_getitem__` method
```
One of these should apparently be an error, but not of this kind, so
this is good ✔️
```diff
-specialtypes_type.py:152:16: error[invalid-type-form] `typing.TypeVar` is not a generic class
-specialtypes_type.py:156:16: error[invalid-type-form] `typing.TypeVar` is not a generic class
```
Good, those were false positives. ✔️
I skipped the analysis for everything involving `TypeVarTuple`.
## Ecosystem impact
**[Full report with detailed
diff](https://david-generic-implicit-alias.ecosystem-663.pages.dev/diff)**
Previous iterations of this PR showed all kinds of problems. In it's
current state, I do not see any large systematic problems, but it is
hard to tell with 5k diagnostic changes.
## Performance
* There is a huge 4x regression in `colour-science/colour`, related to
[this large
file](https://github.com/colour-science/colour/blob/develop/colour/io/luts/tests/test_lut.py)
with [many assignments of hard-coded arrays (lists of lists) to
`np.NDArray`
types](83e754c8b6/colour/io/luts/tests/test_lut.py (L701-L781))
that we now understand. We now take ~2 seconds to check this file, so
definitely not great, but maybe acceptable for now.
## Test Plan
Updated and new Markdown tests
## Summary
This is a bugfix for subtyping of `type[Any]` / `type[T]` and protocols.
## Test Plan
Regression test that will only be really meaningful once
https://github.com/astral-sh/ruff/pull/21553 lands.
## Summary
**This is the final goto-targets with missing
goto-definition/declaration implementations!
You can now theoretically click on all the user-defined names in all the
syntax. 🎉**
This adds:
* goto definition/declaration on patterns/typevars
* find-references/rename on patterns/typevars
* fixes syntax highlighting of `*rest` patterns
This notably *does not* add:
* goto-type for patterns/typevars
* hover for patterns/typevars (because that's just goto-type for names)
Also I realized we were at the precipice of one of the great GotoTarget
sins being resolved, and so I made import aliases also resolve to a
ResolvedDefinition. This removes a ton of cruft and prevents further
backsliding.
Note however that import aliases are, in general, completely jacked up
when it comes to find-references/renames (both before and after this
PR). Previously you could try to rename an import alias and it just
wouldn't do anything. With this change we instead refuse to even let you
try to rename it.
Sorting out why import aliases are jacked up is an ongoing thing I hope
to handle in a followup.
## Test Plan
You'll surely not regret checking in 86 snapshot tests
## Summary
* Fixes https://github.com/astral-sh/ty/issues/1650
* Part of https://github.com/astral-sh/ty/issues/1610
We now handle:
* `.. warning::` (and friends) by bolding the line and rendering the
block as normal (non-code) text
* `.. code::` (and friends) by treating it the same as `::` (fully
deleted if seen, introduce a code block)
* `.. code:: lang` (and friends) by letting it set the language on the
codefence
* `.. versionchanged:: 1.2.3` (and friends) by rendering it like
`warning` but with the version included and italicized
* `.. dsfsdf-unknown:: (lang)` by assuming it's the same as `.. code::
(lang)`
## Test Plan
Snapshots added/updated. I also deleted a bunch of useless checks on
plaintext rendering. It's important for some edge-case tests but not for
the vast majority of tests.
## Summary
This PR adds a new `db` parameter to `Parameters::new` for
https://github.com/astral-sh/ruff/pull/21445. This change creates a
large diff so thought to split it out as it's just a mechanical change.
The `Parameters::new` method not only creates the `Parameters` but also
analyses the parameters to check what kind it is. For `ParamSpec`
support, it's going to require the `db` to check whether the annotated
type is `ParamSpec` or not. For the current set of parameters that isn't
required because it's only checking whether it's dynamic or not which
doesn't require `db`.
## Summary
Originally I planned to feed this in as a `fix` but I realized that we
probably don't want to be trying to resolve import suggestions while
we're doing type inference. Thus I implemented this as a fallback when
there's no fixes on a diagnostic, which can use the full lsp machinery.
Fixes https://github.com/astral-sh/ty/issues/1552
## Test Plan
Works in the IDE, added some e2e tests.
## Summary
Previously if an explicit specialization failed (e.g. wrong number of
type arguments or violates an upper bound) we just inferred `Unknown`
for the entire type. This actually caused us to panic on an a case of a
recursive upper bound with invalid specialization; the upper bound would
oscillate indefinitely in fixpoint iteration between `Unknown` and the
given specialization. This could be fixed with a cycle recovery
function, but in this case there's a simpler fix: if we infer
`C[Unknown]` instead of `Unknown` for an invalid attempt to specialize
`C`, that allows fixpoint iteration to quickly converge, as well as
giving a more precise type inference.
Other type checkers actually just go with the attempted specialization
even if it's invalid. So if `C` has a type parameter with upper bound
`int`, and you say `C[str]`, they'll emit a diagnostic but just go with
`C[str]`. Even weirder, if `C` has a single type parameter and you say
`C[str, bytes]`, they'll just go with `C[str]` as the type. I'm not
convinced by this approach; it seems odd to have specializations
floating around that explicitly violate the declared upper bound, or in
the latter case aren't even the specialization the annotation requested.
I prefer `C[Unknown]` for this case.
Fixing this revealed an issue with `collections.namedtuple`, which
returns `type[tuple[Any, ...]]`. Due to
https://github.com/astral-sh/ty/issues/1649 we consider that to be an
invalid specialization. So previously we returned `Unknown`; after this
PR it would be `type[tuple[Unknown]]`, leading to more false positives
from our lack of functional namedtuple support. To avoid that I added an
explicit Todo type for functional namedtuples for now.
## Test Plan
Added and updated mdtests.
The conformance suite changes have to do with `ParamSpec`, so no
meaningful signal there.
The ecosystem changes appear to be the expected effects of having more
precise type information (including occurrences of known issues such as
https://github.com/astral-sh/ty/issues/1495 ). Most effects are just
changes to types in diagnostics.
## Summary
Lots of Ruff rules encourage you to make changes that might then cause
ty to start complaining about Liskov violations. Most of these Ruff
rules already refrain from complaining about a method if they see that
the method is decorated with `@override`, but this usually isn't
documented. This PR updates the docs of many Ruff rules to note that
they refrain from complaining about `@override`-decorated methods, and
also adds a similar note to the ty `invalid-method-override`
documentation.
Helps with
https://github.com/astral-sh/ty/issues/1644#issuecomment-3581663859
## Test Plan
- `uvx prek run -a` locally
- CI on this PR
## Summary
This PR updates the explicit specialization logic to avoid using the
call machinery.
Previously, the logic would use the call machinery by converting the
list of type variables into a `Binding` with a single `Signature` where
all the type variables are positional-only parameters with bounds and
constraints as the annotated type and the default type as the default
parameter value. This has the advantage that it doesn't need to
implement any specific logic but the disadvantages are subpar diagnostic
messages as it would use the ones specific to a function call. But, an
important disadvantage is that the kind of type variable is lost in this
translation which becomes important in #21445 where a `ParamSpec` can
specialize into a list of types which is provided using list literal.
For example,
```py
class Foo[T, **P]: ...
Foo[int, [int, str]]
```
This PR converts the logic to use a simple loop using `zip_longest` as
all type variables and their corresponding type argument maps on a 1-1
basis. They cannot be specified using keyword argument either e.g.,
`dict[_VT=str, _KT=int]` is invalid.
This PR also makes an initial attempt to improve the diagnostic message
to specifically target the specialization part by using words like "type
argument" instead of just "argument" and including information like the
type variable, bounds, and constraints. Further improvements can be made
by highlighting the type variable definition or the bounds / constraints
as a sub-diagnostic but I'm going to leave that as a follow-up.
## Test Plan
Update messages in existing test cases.
## Summary
This caused "deterministic but chaotic" ordering of some intersection
types in diagnostics. When calling a union, we infer the argument type
once per matching parameter type, intersecting the inferred types for
the argument expression, and we did that in an unpredictable order.
We do need a hashset here for de-duplication. Sometimes we call large
unions where the type for a given parameter is the same across the
union, we should infer the argument once per parameter type, not once
per union element. So use an `FxIndexSet` instead of an `FxHashSet`.
## Test Plan
With this change, switching between `main` and
https://github.com/astral-sh/ruff/pull/21646 no longer changes the
ordering of the intersection type in the test in
cca3a8045d
## Summary
Derived from #17371Fixesastral-sh/ty#256
Fixes https://github.com/astral-sh/ty/issues/1415
Fixes https://github.com/astral-sh/ty/issues/1433
Fixes https://github.com/astral-sh/ty/issues/1524
Properly handles any kind of recursive inference and prevents panics.
---
Let me explain techniques for converging fixed-point iterations during
recursive type inference.
There are two types of type inference that naively don't converge
(causing salsa to panic): divergent type inference and oscillating type
inference.
### Divergent type inference
Divergent type inference occurs when eagerly expanding a recursive type.
A typical example is this:
```python
class C:
def f(self, other: "C"):
self.x = (other.x, 1)
reveal_type(C().x) # revealed: Unknown | tuple[Unknown | tuple[Unknown | tuple[..., Literal[1]], Literal[1]], Literal[1]]
```
To solve this problem, we have already introduced `Divergent` types
(https://github.com/astral-sh/ruff/pull/20312). `Divergent` types are
treated as a kind of dynamic type [^1].
```python
Unknown | tuple[Unknown | tuple[Unknown | tuple[..., Literal[1]], Literal[1]], Literal[1]]
=> Unknown | tuple[Divergent, Literal[1]]
```
When a query function that returns a type enters a cycle, it sets
`Divergent` as the cycle initial value (instead of `Never`). Then, in
the cycle recovery function, it reduces the nesting of types containing
`Divergent` to converge.
```python
0th: Divergent
1st: Unknown | tuple[Divergent, Literal[1]]
2nd: Unknown | tuple[Unknown | tuple[Divergent, Literal[1]], Literal[1]]
=> Unknown | tuple[Divergent, Literal[1]]
```
Each cycle recovery function for each query should operate only on the
`Divergent` type originating from that query.
For this reason, while `Divergent` appears the same as `Any` to the
user, it internally carries some information: the location where the
cycle occurred. Previously, we roughly identified this by having the
scope where the cycle occurred, but with the update to salsa, functions
that create cycle initial values can now receive a `salsa::Id`
(https://github.com/salsa-rs/salsa/pull/1012). This is an opaque ID that
uniquely identifies the cycle head (the query that is the starting point
for the fixed-point iteration). `Divergent` now has this `salsa::Id`.
### Oscillating type inference
Now, another thing to consider is oscillating type inference.
Oscillating type inference arises from the fact that monotonicity is
broken. Monotonicity here means that for a query function, if it enters
a cycle, the calculation must start from a "bottom value" and progress
towards the final result with each cycle. Monotonicity breaks down in
type systems that have features like overloading and overriding.
```python
class Base:
def flip(self) -> "Sub":
return Sub()
class Sub(Base):
def flip(self) -> "Base":
return Base()
class C:
def __init__(self, x: Sub):
self.x = x
def replace_with(self, other: "C"):
self.x = other.x.flip()
reveal_type(C(Sub()).x)
```
Naive fixed-point iteration results in `Divergent -> Sub -> Base -> Sub
-> ...`, which oscillates forever without diverging or converging. To
address this, the salsa API has been modified so that the cycle recovery
function receives the value of the previous cycle
(https://github.com/salsa-rs/salsa/pull/1012).
The cycle recovery function returns the union type of the current cycle
and the previous cycle. In the above example, the result type for each
cycle is `Divergent -> Sub -> Base (= Sub | Base) -> Base`, which
converges.
The final result of oscillating type inference does not contain
`Divergent` because `Divergent` that appears in a union type can be
removed, as is clear from the expansion. This simplification is
performed at the same time as nesting reduction.
```
T | Divergent = T | (T | (T | ...)) = T
```
[^1]: In theory, it may be possible to strictly treat types containing
`Divergent` types as recursive types, but we probably shouldn't go that
deep yet. (AFAIK, there are no PEPs that specify how to handle
implicitly recursive types that aren't named by type aliases)
## Performance analysis
A happy side effect of this PR is that we've observed widespread
performance improvements!
This is likely due to the removal of the `ITERATIONS_BEFORE_FALLBACK`
and max-specialization depth trick
(https://github.com/astral-sh/ty/issues/1433,
https://github.com/astral-sh/ty/issues/1415), which means we reach a
fixed point much sooner.
## Ecosystem analysis
The changes look good overall.
You may notice changes in the converged values for recursive types,
this is because the way recursive types are normalized has been changed.
Previously, types containing `Divergent` types were normalized by
replacing them with the `Divergent` type itself, but in this PR, types
with a nesting level of 2 or more that contain `Divergent` types are
normalized by replacing them with a type with a nesting level of 1. This
means that information about the non-divergent parts of recursive types
is no longer lost.
```python
# previous
tuple[tuple[Divergent, int], int] => Divergent
# now
tuple[tuple[Divergent, int], int] => tuple[Divergent, int]
```
The false positive error introduced in this PR occurs in class
definitions with self-referential base classes, such as the one below.
```python
from typing_extensions import Generic, TypeVar
T = TypeVar("T")
U = TypeVar("U")
class Base2(Generic[T, U]): ...
# TODO: no error
# error: [unsupported-base] "Unsupported class base with type `<class 'Base2[Sub2, U@Sub2]'> | <class 'Base2[Sub2[Unknown], U@Sub2]'>`"
class Sub2(Base2["Sub2", U]): ...
```
This is due to the lack of support for unions of MROs, or because cyclic
legacy generic types are not inferred as generic types early in the
query cycle.
## Test Plan
All samples listed in astral-sh/ty#256 are tested and passed without any
panic!
## Acknowledgments
Thanks to @MichaReiser for working on bug fixes and improvements to
salsa for this PR. @carljm also contributed early on to the discussion
of the query convergence mechanism proposed in this PR.
---------
Co-authored-by: Carl Meyer <carl@astral.sh>
## Summary
We now use the type context for a lot of things, so re-inferring without
type context actually makes diagnostics more confusing (in most cases).
Autocomplete suggestions were not suppressed correctly during
some variable bindings if the parameter name was currently
matching a keyword. E.g. `def f(foo<CURSOR>` was handled
correctly but not `def f(in<CURSOR>`.
Previously we extracted the entire token as the query
independently of the cursor position. By not doing that
you avoid having to do special range handling
to figure out the start position of the current token.
It's likely also more intuitive from a user perspective
to only consider characters left of the cursor when
suggesting autocompletions.
## Summary
The implementation here is to just record the idents of these statements
in `scopes_by_expression` (which already supported idents but only ones
that happened to appear in expressions), so that `definitions_for_name`
Just Works.
goto-type (and therefore hover) notably does not work on these
statements because the typechecker does not record info for them. I am
tempted to just introduce `type_for_name` which runs
`definitions_for_name` to find other expressions and queries the
inferred type... but that's a bit whack because it won't be the computed
type at the right point in the code. It probably wouldn't be
particularly expensive to just compute/record the type at those nodes,
as if they were a load, because global/nonlocal is so scarce?
## Test Plan
Snapshot tests added/re-enabled.
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## Summary
Don't allow edits of some more invalid syntax types.
## Test Plan
Add a test for `x = Literal['a']` (similar) to show we don't allow
edits.
Fixes https://github.com/astral-sh/ty/issues/1009
## Summary
This adds support for:
* semantic-tokens (syntax highlighting)
* goto-type **(partially implemented, but want to land as-is)**
* goto-declaration
* goto-definition (falls out of goto-declaration)
* hover **(limited by goto-type)**
* find-references
* rename-references (falls out of find-references)
There are 3 major things being introduced here:
* `TypeInferenceBuilder::string_annotations` is a `FxHashSet` of exprs
which were determined to be string annotations during inference. It's
bubbled up in `extras` to hopefully minimize the overhead as in most
contexts it's empty.
* Very happy to hear if this is too hacky and if I should do something
better, but it's IMO important that we get an authoritative answer on
whether something is a string annotation or not.
* `SemanticModel::enter_string_annotation` checks if the expr was marked
by `TypeInferenceBuilder::string_annotations` and then parses the subast
and produces a sub-SemanticModel that sets
`SemanticModel::in_string_annotation_expr`. This expr will be used by
the model whenever we need to query e.g. the scope of the current
expression (otherwise the code will constantly panic as the subast nodes
are not in the current File's AST)
* This hazard consequently encouraged me to refactor a bunch of code to
replace uses of file/db with SemanticModel to minimize hazards (it is no
longer as safe to randomly materialize a SemanticModel in the middle of
analysis, you need to thread through the one you have in case it has
`in_string_annotation_expr` set).
* `GotoTarget::StringAnnotationSubexpr` (and a semantic-tokens impl)
which involves invoking `SemanticModel::enter_string_annotation` before
invoking the same kind of subroutine a normal expression would.
* goto-type (and consequently displaying the type in hover) is the main
hole here, because we can only get the type iff the string annotation is
the entire subexpression (i.e. we can get the type of `"int"` but not
the parts of `"int | str"`). This is shippable IMO.
## Test Plan
Messed around in IDE, wrote a ton of tests.
## Summary
This PR adds a code action to remove unused ignore comments.
This PR also includes some infrastructure boilerplate to set up code
actions in the editor:
* Extend `snapshot-diagnostics` to render fixes
* Render fixes when using `--output-format=full`
* Hook up edits and the code action request in the LSP
* Add the `Unnecessary` tag to `unused-ignore-comment` diagnostics
* Group multiple unused codes into a single diagnostic
The same fix can be used on the CLI once we add `ty fix`
Note: `unused-ignore-comment` is currently disabled by default.
https://github.com/user-attachments/assets/f9e21087-3513-4156-85d7-a90b1a7a3489
## Summary
Building on https://github.com/astral-sh/ruff/pull/21436.
There's nothing conceptually more complicated about this, it just
requires its own set of tests and its own subdiagnostic hint.
I also uncovered another inconsistency between mypy/pyright/pyrefly,
which is fun. In this case, I suggest we go with pyright's behaviour.
## Test Plan
mdtests/snapshots
## Summary
For something like this:
```py
from typing import Callable
def my_lossy_decorator(fn: Callable[..., int]) -> Callable[..., int]:
return fn
class MyClass:
@my_lossy_decorator
def method(self) -> int:
return 42
```
we will currently infer the type of `MyClass.method` as a function-like
`Callable`, but we will infer the type of `MyClass().method` as a
`Callable` that is _not_ function-like. That's because a `CallableType`
currently "forgets" whether it was function-like or not during the
`bound_self` transformation:
a57e291311/crates/ty_python_semantic/src/types.rs (L10985-L10987)
This seems incorrect, and it's quite different to what we do when
binding the `self` parameter of `FunctionLiteral` types: `BoundMethod`
types are all seen as subtypes of function-like `Callable` supertypes --
here's `BoundMethodType::into_callable_type`:
a57e291311/crates/ty_python_semantic/src/types.rs (L10844-L10860)
The bug here is also causing lots of false positives in the ecosystem
report on https://github.com/astral-sh/ruff/pull/21611: a decorated
method on a subclass is currently not seen as validly overriding an
undecorated method with the same signature on a superclass, because the
undecorated superclass method is seen as function-like after binding
`self` whereas the decorated subclass method is not.
Fixing the bug required adding a new API in `protocol_class.rs`, because
it turns out that for our purposes in protocol subtyping/assignability,
we really do want a callable type to forget its function-like-ness when
binding `self`.
I initially tried out this change without changing anything in
`protocol_class.rs`. However, it resulted in many ecosystem false
positives and new false positives on the typing conformance test suite.
This is because it would mean that no protocol with a `__call__` method
would ever be seen as a subtype of a `Callable` type, since the
`__call__` method on the protocol would be seen as being function-like
whereas the `Callable` type would not be seen as function-like.
## Test Plan
Added an mdtest that fails on `main`
Before, we would collapse any constraint of the form `Never ≤ T ≤
object` down to the "always true" constraint set. This is correct in
terms of BDD semantics, but loses information, since "not constraining a
typevar at all" is different than "constraining a typevar to take on any
type". Once we get to specialization inference, we should fall back on
the typevar's default for the former, but not for the latter.
This is much easier to support now that we have a sequent map, since we
need to treat `¬(Never ≤ T ≤ object)` as being impossible, and prune it
when we walk through BDD paths, just like we do for other impossible
combinations.
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## Summary
Resolves
https://github.com/astral-sh/ty/issues/317#issuecomment-3567398107.
I can't get the auto import working great.
I haven't added many places where we specify that the type display is
invalid syntax.
## Test Plan
Nothing yet
This patch updates our protocol assignability checks to substitute for
any occurrences of `typing.Self` in method signatures, replacing it with
the class being checked for assignability against the protocol.
This requires a new helper method on signatures, `apply_self`, which
substitutes occurrences of `typing.Self` _without_ binding the `self`
parameter.
We also update the `try_upcast_to_callable` method. Before, it would
return a `Type`, since certain types upcast to a _union_ of callables,
not to a single callable. However, even in that case, we know that every
element of the union is a callable. We now return a vector of
`CallableType`. (Actually a smallvec to handle the most common case of a
single callable; and wrapped in a new type so that we can provide helper
methods.) If there is more than one element in the result, it represents
a union of callables. This lets callers get at the `CallableType`
instances in a more type-safe way. (This makes it easier for our
protocol checking code to call the new `apply_self` helper.) We also
provide an `into_type` method so that callers that really do want a
`Type` can get the original result easily.
---------
Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>
Aria Desires
Dylan
David Peter
Alex Waygood
Matthew Mckee
Micha Reiser
Dhruv Manilawala
Ibraheem Ahmed
Tsvika Shapira
Carl Meyer
Shunsuke Shibayama
Dan Parizher
Luca Chiodini
Shahar Naveh
Rasmus Nygren
Jack O'Connor
Douglas Creager