## Summary
Our internal inlay hints structure (`ty_ide::InlayHint`) now more
closely resembles `lsp_types::InlayHint`.
This mainly allows us to convert to `lsp_types::InlayHint` with less
hassle, but it also allows us to manage the different parts of the inlay
hint better, which in the future will allow us to implement features
like goto on the type part of the type inlay hint.
It also really isn't important to store a specific `Type` instance in
the `InlayHintContent`. So we remove this and use `InlayHintLabel`
instead which just shows the representation of the type (along with
other information).
We see a similar structure used in rust-analyzer too.
## Summary
This has been here for awhile (since our initial PEP 695 type alias
support) but isn't really correct. The right-hand-side of a PEP 695 type
alias is a distinct scope, and we don't mark it as an "eager" nested
scope, so it automatically gets "deferred" resolution of names from
outer scopes (just like a nested function). Thus it's
redundant/unnecessary for us to use `DeferredExpressionState::Deferred`
for resolving that RHS expression -- that's for deferring resolution of
individual names within a scope. Using it here causes us to wrongly
ignore applicable outer-scope narrowing.
## Test Plan
Added mdtest that failed before this PR (the second snippet -- the first
snippet always passed.)
## Summary
As noted in a code TODO, our `Diff` rendering code previously didn't
have any
special handling for notebooks. This was particularly obvious when the
diffs
were rendered right next to the corresponding diagnostic because the
diagnostic
used cell-based line numbers, while the diff was still using line
numbers from
the concatenated source. This PR updates the diff rendering to handle
notebooks
too.
The main improvements shown in the example below are:
- Line numbers are now remapped to be relative to their cell
- Context lines from other cells are suppressed
```
error[unused-import][*]: `math` imported but unused
--> notebook.ipynb:cell 2:2:8
|
1 | # cell 2
2 | import math
| ^^^^
3 |
4 | print('hello world')
|
help: Remove unused import: `math`
ℹ Safe fix
1 1 | # cell 2
2 |-import math
3 2 |
4 3 | print('hello world')
```
I tried a few different approaches here before finally just splitting
the notebook into separate text ranges by cell and diffing each one
separately. It seems to work and passes all of our tests, but I don't
know if it's actually enforced anywhere that a single edit doesn't span
cells. Such an edit would silently be dropped right now since it would
fail the `contains_range` check. I also feel like I may have overlooked
an existing way to partition a file into cells like this.
## Test Plan
Existing notebook tests, plus a new one in `ruff_db`
## Summary
Implement validation for `TypedDict` constructor calls and dictionary
literal assignments, including support for `total=False` and proper
field management.
Also add support for `Required` and `NotRequired` type qualifiers in
`TypedDict` classes, along with proper inheritance behavior and the
`total=` parameter.
Support both constructor calls and dict literal syntax
part of https://github.com/astral-sh/ty/issues/154
### Basic Required Field Validation
```py
class Person(TypedDict):
name: str
age: int | None
# Error: Missing required field 'name' in TypedDict `Person` constructor
incomplete = Person(age=25)
# Error: Invalid argument to key "name" with declared type `str` on TypedDict `Person`
wrong_type = Person(name=123, age=25)
# Error: Invalid key access on TypedDict `Person`: Unknown key "extra"
extra_field = Person(name="Bob", age=25, extra=True)
```
<img width="773" height="191" alt="Screenshot 2025-08-07 at 17 59 22"
src="https://github.com/user-attachments/assets/79076d98-e85f-4495-93d6-a731aa72a5c9"
/>
### Support for `total=False`
```py
class OptionalPerson(TypedDict, total=False):
name: str
age: int | None
# All valid - all fields are optional with total=False
charlie = OptionalPerson()
david = OptionalPerson(name="David")
emily = OptionalPerson(age=30)
frank = OptionalPerson(name="Frank", age=25)
# But type validation and extra fields still apply
invalid_type = OptionalPerson(name=123) # Error: Invalid argument type
invalid_extra = OptionalPerson(extra=True) # Error: Invalid key access
```
### Dictionary Literal Validation
```py
# Type checking works for both constructors and dict literals
person: Person = {"name": "Alice", "age": 30}
reveal_type(person["name"]) # revealed: str
reveal_type(person["age"]) # revealed: int | None
# Error: Invalid key access on TypedDict `Person`: Unknown key "non_existing"
reveal_type(person["non_existing"]) # revealed: Unknown
```
### `Required`, `NotRequired`, `total`
```python
from typing import TypedDict
from typing_extensions import Required, NotRequired
class PartialUser(TypedDict, total=False):
name: Required[str] # Required despite total=False
age: int # Optional due to total=False
email: NotRequired[str] # Explicitly optional (redundant)
class User(TypedDict):
name: Required[str] # Explicitly required (redundant)
age: int # Required due to total=True
bio: NotRequired[str] # Optional despite total=True
# Valid constructions
partial = PartialUser(name="Alice") # name required, age optional
full = User(name="Bob", age=25) # name and age required, bio optional
# Inheritance maintains original field requirements
class Employee(PartialUser):
department: str # Required (new field)
# name: still Required (inherited)
# age: still optional (inherited)
emp = Employee(name="Charlie", department="Engineering") # ✅
Employee(department="Engineering") # ❌
e: Employee = {"age": 1} # ❌
```
<img width="898" height="683" alt="Screenshot 2025-08-11 at 22 02 57"
src="https://github.com/user-attachments/assets/4c1b18cd-cb2e-493a-a948-51589d121738"
/>
## Implementation
The implementation reuses existing validation logic done in
https://github.com/astral-sh/ruff/pull/19782
### ℹ️ Why I did NOT synthesize an `__init__` for `TypedDict`:
`TypedDict` inherits `dict.__init__(self, *args, **kwargs)` that accepts
all arguments.
The type resolution system finds this inherited signature **before**
looking for synthesized members.
So `own_synthesized_member()` is never called because a signature
already exists.
To force synthesis, you'd have to override Python’s inheritance
mechanism, which would break compatibility with the existing ecosystem.
This is why I went with ad-hoc validation. IMO it's the only viable
approach that respects Python’s
inheritance semantics while providing the required validation.
### Refacto of `Field`
**Before:**
```rust
struct Field<'db> {
declared_ty: Type<'db>,
default_ty: Option<Type<'db>>, // NamedTuple and dataclass only
init_only: bool, // dataclass only
init: bool, // dataclass only
is_required: Option<bool>, // TypedDict only
}
```
**After:**
```rust
struct Field<'db> {
declared_ty: Type<'db>,
kind: FieldKind<'db>,
}
enum FieldKind<'db> {
NamedTuple { default_ty: Option<Type<'db>> },
Dataclass { default_ty: Option<Type<'db>>, init_only: bool, init: bool },
TypedDict { is_required: bool },
}
```
## Test Plan
Updated Markdown tests
---------
Co-authored-by: David Peter <mail@david-peter.de>
## Summary
This PR limits the argument type expansion size for an overload call
evaluation to 512.
The limit chosen is arbitrary but I've taken the 256 limit from Pyright
into account and bumped it x2 to start with.
Initially, I actually started out by trying to refactor the entire
argument type expansion to be lazy. Currently, expanding a single
argument at any position eagerly creates the combination (argument
lists) and returns that (`Vec<CallArguments>`) but I thought we could
make it lazier by converting the return type of `expand` from
`Iterator<Item = Vec<CallArguments>>` to `Iterator<Item = Iterator<Item
= CallArguments>>` but that's proving to be difficult to implement
mainly because we **need** to maintain the previous expansion to
generate the next expansion which is the main reason to use
`std::iter::successors` in the first place.
Another approach would be to eagerly expand all the argument types and
then use the `combinations` from `itertools` to generate the
combinations but we would need to find the "boundary" between arguments
lists produced from expanding argument at position 1 and position 2
because that's important for the algorithm.
Closes: https://github.com/astral-sh/ty/issues/868
## Test Plan
Add test case to demonstrate the limit along with the diagnostic
snapshot stating that the limit has been reached.
Part of astral-sh/ty#994
## Summary
Add new special forms to `ty_extensions`, `Top[T]` and `Bottom[T]`.
Remove `ty_extensions.top_materialization` and
`ty_extensions.bottom_materialization`.
## Test Plan
Converted the existing `materialization.md` mdtest to the new syntax.
Added some tests for invalid use of the new special form.
In effect, we make the Salsa query aspect keyed only on whether we want
global symbols. We move everything else (hierarchical and querying) to
an aggregate step *after* the query.
This was a somewhat involved change since we want to return a flattened
list from visiting the source while also preserving enough information
to reform the symbols into a hierarchical structure that the LSP
expects. But I think overall the API has gotten simpler and we encode
more invariants into the type system. (For example, previously you got a
runtime assertion if you tried to provide a query string while enabling
hierarchical mode. But now that's prevented by construction.)
Basically, this splits the implementation into two pieces:
the first piece does the traversal and finds *all* symbols
across the workspace. The second piece does filtering based
on a user provided query string. Only the first piece is
cached by Salsa.
This brings warm "workspace symbols" requests down from
500-600ms to 100-200ms.
While this doesn't typically matter, when ty returns a very
large list of symbols, this can have an impact. Specifically,
when searching `async` in home-assistant, this gets times
closer to 500ms versus closer to 600ms before this change.
It looks like an overall ~50ms improvement (so around 10%),
but variance is all over the place and I didn't do any
statistical tests.
But this does make intuitive sense. Previously, we were
allocating intermediate strings, doing UTF-8 decoding and
consulting Unicode casing tables. Now we're just doing what
is likely a single DFA scan. In effect, we front load all
of the Unicode junk into regex compilation.
There is a small amount of subtlety to this matching routine,
and it could be implemented in a faster way. So let's right some
tests for what we have to ensure we don't break anything when
we optimize it.
## Summary
Looks like an oversight at some point that led to two identical globals,
the one in `ty_project` just calls `ty_python_semantic::register_lints`.
## Summary
Removes the `module_ptr` field from `AstNodeRef` in release mode, and
change `NodeIndex` to a `NonZeroU32` to reduce the size of
`Option<AstNodeRef<_>>` fields.
I believe CI runs in debug mode, so this won't show up in the memory
report, but this reduces memory by ~2% in release mode.
## Summary
Previously we held off from doing this because we weren't sure that it
was worth the added complexity cost. But our code has changed in the
months since we made that initial decision, and I think the structure of
the code is such that it no longer really leads to much added complexity
to add precise inference when unpacking a string literal or a bytes
literal.
The improved inference we gain from this has real benefits to users (see
the mypy_primer report), and this PR doesn't appear to have a
performance impact.
## Test plan
mdtests
## Summary
We use the `System` abstraction in ty to abstract away the host/system
on which ty runs.
This has a few benefits:
* Tests can run in full isolation using a memory system (that uses an
in-memory file system)
* The LSP has a custom implementation where `read_to_string` returns the
content as seen by the editor (e.g. unsaved changes) instead of always
returning the content as it is stored on disk
* We don't require any file system polyfills for wasm in the browser
However, it does require extra care that we don't accidentally use
`std::fs` or `std::env` (etc.) methods in ty's code base (which is very
easy).
This PR sets up Clippy and disallows the most common methods, instead
pointing users towards the corresponding `System` methods.
The setup is a bit awkward because clippy doesn't support inheriting
configurations. That means, a crate can only override the entire
workspace configuration or not at all.
The approach taken in this PR is:
* Configure the disallowed methods at the workspace level
* Allow `disallowed_methods` at the workspace level
* Enable the lint at the crate level using the warn attribute (in code)
The obvious downside is that it won't work if we ever want to disallow
other methods, but we can figure that out once we reach that point.
What about false positives: Just add an `allow` and move on with your
life :) This isn't something that we have to enforce strictly; the goal
is to catch accidental misuse.
## Test Plan
Clippy found a place where we incorrectly used `std::fs::read_to_string`
Adds a method to `TStringValue` to detect whether the t-string is empty
_as an iterable_. Note the subtlety here that, unlike f-strings, an
empty t-string is still truthy (i.e. `bool(t"")==True`).
Closes#19951
## Summary
Rename `TypeAliasType::Bare` to `TypeAliasType::ManualPEP695`, and
`BareTypeAliasType` to `ManualPEP695TypeAliasType`.
Why?
Both existing variants of `TypeAliasType` are specific to features added
in PEP 695 (which introduced both the `type` statement and
`types.TypeAliasType`), so it doesn't make sense to name one with the
name `PEP695` and not the other.
A "bare" type alias, in my mind, is a legacy type alias like `IntOrStr =
int | str`, which is "bare" in that there is nothing at all
distinguishing it as a type alias. I will want to use the "bare" name
for this variant, in a future PR.
The renamed variant here describes a type alias created with `IntOrStr =
types.TypeAliasType("IntOrStr", int | str)`, which is not "bare", it's
just "manually" instantiated instead of using the `type` statement
syntax sugar. (This is useful when using the `typing_extensions`
backport of `TypeAliasType` on older Python versions.)
## Test Plan
Pure rename, existing tests pass.
## Summary
This PR fixes https://github.com/astral-sh/ty/issues/1071
The core issue is that `CallableType` is a salsa interned but
`Signature` (which `CallableType` stores) ignores the `Definition` in
its `Eq` and `Hash` implementation.
This PR tries to simplest fix by removing the custom `Eq` and `Hash`
implementation. The main downside of this fix is that it can increase
memory usage because `CallableType`s that are equal except for their
`Definition` are now interned separately.
The alternative is to remove `Definition` from `CallableType` and
instead, call `bindings` directly on the callee (call_expression.func).
However, this would require
addressing the TODO
here
39ee71c2a5/crates/ty_python_semantic/src/types.rs (L4582-L4586)
This might probably be worth addressing anyway, but is the more involved
fix. That's why I opted for removing the custom `Eq` implementation.
We already "ignore" the definition during normalization, thank's to
Alex's work in https://github.com/astral-sh/ruff/pull/19615
## Test Plan
https://github.com/user-attachments/assets/248d1cb1-12fd-4441-adab-b7e0866d23eb
While implementing similar logic for initializers I noticed that this
code appeared to be walking the ancestors in the wrong direction, and so
if you have nested function calls it would always grab the outermost one
instead of the closest-ancestor.
The four copies of the test are because there's something really evil in
our caching that can't seem to be demonstrated in our cursor testing
framework, which I'm filing a followup for.
Summary
--
This is a preparatory PR in support of #19919. It moves our `Diff`
rendering code from `ruff_linter` to `ruff_db`, where we have direct
access to the `DiagnosticStylesheet` used by our other diagnostic
rendering code. As shown by the tests, this shouldn't cause any visible
changes. The colors aren't exactly the same, as I note in a TODO
comment, but I don't think there's any existing way to see those, even
in tests.
The `Diff` implementation is mostly unchanged. I just switched from a
Ruff-specific `SourceFile` to a `DiagnosticSource` (removing an
`expect_ruff_source_file` call) and updated the `LineStyle` struct and
other styling calls to use `fmt_styled` and our existing stylesheet.
In support of these changes, I added three styles to our stylesheet:
`insertion` and `deletion` for the corresponding diff operations, and
`underline`, which apparently we _can_ use, as I hoped on Discord. This
isn't supported in all terminals, though. It worked in ghostty but not
in st for me.
I moved the `calculate_print_width` function from the now-deleted
`diff.rs` to a method on `OneIndexed`, where it was available everywhere
we needed it. I'm not sure if that's desirable, or if my other changes
to the function are either (using `ilog10` instead of a loop). This does
make it `const` and slightly simplifies things in my opinion, but I'm
happy to revert it if preferred.
I also inlined a version of `show_nonprinting` from the
`ShowNonprinting` trait in `ruff_linter`:
f4be05a83b/crates/ruff_linter/src/text_helpers.rs (L3-L5)
This trait is now only used in `source_kind.rs`, so I'm not sure it's
worth having the trait or the macro-generated implementation (which is
only called once). This is obviously closely related to our unprintable
character handling in diagnostic rendering, but the usage seems
different enough not to try to combine them.
f4be05a83b/crates/ruff_db/src/diagnostic/render.rs (L990-L998)
We could also move the trait to another crate where we can use it in
`ruff_db` instead of inlining here, of course.
Finally, this PR makes `TextEmitter` a very thin wrapper around a
`DisplayDiagnosticsConfig`. It's still used in a few places, though,
unlike the other emitters we've replaced, so I figured it was worth
keeping around. It's a pretty nice API for setting all of the options on
the config and then passing that along to a `DisplayDiagnostics`.
Test Plan
--
Existing snapshot tests with diffs
"Why would you do this? This looks like you just replaced `bool` with an
overly complex trait"
Yes that's correct!
This should be a no-op refactoring. It replaces all of the logic in our
assignability, subtyping, equivalence, and disjointness methods to work
over an arbitrary `Constraints` trait instead of only working on `bool`.
The methods that `Constraints` provides looks very much like what we get
from `bool`. But soon we will add a new impl of this trait, and some new
methods, that let us express "fuzzy" constraints that aren't always true
or false. (In particular, a constraint will express the upper and lower
bounds of the allowed specializations of a typevar.)
Even once we have that, most of the operations that we perform on
constraint sets will be the usual boolean operations, just on sets.
(`false` becomes empty/never; `true` becomes universe/always; `or`
becomes union; `and` becomes intersection; `not` becomes negation.) So
it's helpful to have this separate PR to refactor how we invoke those
operations without introducing the new functionality yet.
Note that we also have translations of `Option::is_some_and` and
`is_none_or`, and of `Iterator::any` and `all`, and that the `and`,
`or`, `when_any`, and `when_all` methods are meant to short-circuit,
just like the corresponding boolean operations. For constraint sets,
that depends on being able to implement the `is_always` and `is_never`
trait methods.
---------
Co-authored-by: Carl Meyer <carl@astral.sh>
Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>
## Summary
Part of: https://github.com/astral-sh/ty/issues/868
This PR adds a heuristic to avoid argument type expansion if it's going
to eventually lead to no matching overload.
This is done by checking whether the non-expandable argument types are
assignable to the corresponding annotated parameter type. If one of them
is not assignable to all of the remaining overloads, then argument type
expansion isn't going to help.
## Test Plan
Add mdtest that would otherwise take a long time because of the number
of arguments that it would need to expand (30).
This is a fairly simple but effective way to add docstrings to like 95%
of completions from initial experimentation.
Fixes https://github.com/astral-sh/ty/issues/1036
Although ironically this approach *does not* work specifically for
`print` and I haven't looked into why.
## Summary
Resolves#19561
Fixes the [unnecessary-future-import
(UP010)](https://docs.astral.sh/ruff/rules/unnecessary-future-import/)
rule to correctly identify when imported __future__ modules are actually
used in the code, preventing false positives.
I assume there is no way to check usage in `analyze::statements`,
because we don't have any usage bindings for imports. To determine
unused imports, we have to fully scan the file to create bindings and
then check usage, similar to [unused-import
(F401)](https://docs.astral.sh/ruff/rules/unused-import/#unused-import-f401).
So, `Rule::UnnecessaryFutureImport` was moved from the
`analyze::statements` to the `analyze::deferred_scopes` stage. This
caused the need to change the logic of future import handling to a
bindings-based approach.
Also, the diagnostic report was changed.
Before
```
|
1 | from __future__ import nested_scopes, generators
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ UP010
```
after
```
|
1 | from __future__ import nested_scopes, generators
| ^^^^^^^^^^^^^ UP010
```
I believe this is the correct way, because `generators` may be used, but
`nested_scopes` is not.
### Special case
I've found out about some specific case.
```python
from __future__ import nested_scopes
nested_scopes = 1
```
Here we can treat `nested_scopes` as an unused import because the
variable `nested_scopes` shadows it and we can safely remove the future
import (my fix does it).
But
[F401](https://docs.astral.sh/ruff/rules/unused-import/#unused-import-f401)
not triggered for such case
([sandbox](https://play.ruff.rs/296d9c7e-0f02-4659-b0c0-78cc21f3de76))
```
from foo import print_function
print_function = 1
```
In my mind, `print_function` here is an unused import and should be
deleted (my IDE highlight it). What do you think?
## Test Plan
Added test cases and snapshots:
- Split test file into separate _0 and _1 files for appropriate checks.
- Added test cases to verify fixes when future module are used.
---------
Co-authored-by: Igor Drokin <drokinii1017@gmail.com>
This commit corrects the type checker's behavior when handling
`dataclass_transform` decorators that don't explicitly specify
`field_specifiers`. According to [PEP 681 (Data Class
Transforms)](https://peps.python.org/pep-0681/#dataclass-transform-parameters),
when `field_specifiers` is not provided, it defaults to an empty tuple,
meaning no field specifiers are supported and
`dataclasses.field`/`dataclasses.Field` calls should be ignored.
Fixes https://github.com/astral-sh/ty/issues/980
