## 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
Closesastral-sh/ty#456. Part of astral-sh/ty#994.
After all the foundational work, this is only a small change, but let's
see if it exposes any unresolved issues.
## Summary
Part of astral-sh/ty#994. The goal of this PR was to add correct
behavior for attribute access on the top and bottom materializations.
This is necessary for the end goal of using the top materialization for
narrowing generics (`isinstance(x, list)`): we want methods like
`x.append` to work correctly in that case.
It turned out to be convenient to represent materialization as a
TypeMapping, so it can be stashed in the `type_mappings` list of a
function object. This also allowed me to remove most concrete
`materialize` methods, since they usually just delegate to the subparts
of the type, the same as other type mappings. That is why the net effect
of this PR is to remove a few hundred lines.
## Test Plan
I added a few more tests. Much of this PR is refactoring and covered by
existing tests.
## Followups
Assigning to attributes of top materializations is not yet covered. This
seems less important so I'd like to defer it.
I noticed that the `materialize` implementation of `Parameters` was
wrong; it did the same for the top and bottom materializations. This PR
makes the bottom materialization slightly more reasonable, but
implementing this correctly will require extending the struct.
## Summary
Two minor cleanups:
- Return `Option<ClassType>` rather than `Option<ClassLiteral>` from
`TypeInferenceBuilder::class_context_of_current_method`. Now that
`ClassType::is_protocol` exists as a method as well as
`ClassLiteral::is_protocol`, this simplifies most of the call-sites of
the `class_context_of_current_method()` method.
- Make more use of the `MethodDecorator::try_from_fn_type` method in
`class.rs`. Under the hood, this method uses the new methods
`FunctionType::is_classmethod()` and `FunctionType::is_staticmethod()`
that @sharkdp recently added, so it gets the semantics more precisely
correct than the code it's replacing in `infer.rs` (by accounting for
implicit staticmethods/classmethods as well as explicit ones). By using
these methods we can delete some code elsewhere (the
`FunctionDecorators::from_decorator_types()` constructor)
## Test Plan
Existing tests
## Summary
A small set of additional tests for `TypedDict` that I wrote while going
through the spec. Note that this certainly doesn't make the test suite
exhaustive (see remaining open points in the updated list here:
https://github.com/astral-sh/ty/issues/154).
This PR adds two new `ty_extensions` functions,
`reveal_when_assignable_to` and `reveal_when_subtype_of`. These are
closely related to the existing `is_assignable_to` and `is_subtype_of`,
but instead of returning when the property (always) holds, it produces a
diagnostic that describes _when_ the property holds. (This will let us
construct mdtests that print out constraints that are not always true or
always false — though we don't currently have any instances of those.)
I did not replace _every_ occurrence of the `is_property` variants in
the mdtest suite, instead focusing on the generics-related tests where
it will be important to see the full detail of the constraint sets.
As part of this, I also updated the mdtest harness to accept the shorter
`# revealed:` assertion format for more than just `reveal_type`, and
updated the existing uses of `reveal_protocol_interface` to take
advantage of this.
## Summary
Pull this out of https://github.com/astral-sh/ruff/pull/18473 as an
isolated change to make sure it has no adverse effects.
The wrong behavior is observable on `main` for something like
```py
class C:
def __new__(cls) -> "C":
cls.x = 1
C.x # previously: Attribute `x` can only be accessed on instances
# now: Type `<class 'C'>` has no attribute `x`
```
where we currently treat `x` as an *instance* attribute (because we
consider `__new__` to be a normal function and `cls` to be the "self"
attribute). With this PR, we do not consider `x` to be an attribute,
neither on the class nor on instances of `C`. If this turns out to be an
important feature, we should add it intentionally, instead of
accidentally.
## Test Plan
Ecosystem checks.
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## Summary
This PR implements
https://docs.astral.sh/ruff/rules/yield-from-in-async-function/ as a
syntax semantic error
## Test Plan
<!-- How was it tested? -->
I have written a simple inline test as directed in
[https://github.com/astral-sh/ruff/issues/17412](https://github.com/astral-sh/ruff/issues/17412)
---------
Signed-off-by: 11happy <soni5happy@gmail.com>
Co-authored-by: Alex Waygood <alex.waygood@gmail.com>
Co-authored-by: Brent Westbrook <36778786+ntBre@users.noreply.github.com>
This re-works the `all_symbols` based added previously to work across
all modules available, and not just what is directly in the workspace.
Note that we always pass an empty string as a query, which makes the
results always empty. We'll fix this in a subsequent commit.
This is to facilitate recursive traversal of all modules in an
environment. This way, we can keep asking for submodules.
This also simplifies how this is used in completions, and probably makes
it faster. Namely, since we return the `Module` itself, callers don't
need to invoke the full module resolver just to get the module type.
Note that this doesn't include namespace packages. (Which were
previously not supported in `Module::all_submodules`.) Given how they
can be spread out across multiple search paths, they will likely require
special consideration here.
This is similar to a change made in the "list top-level modules"
implementation that had been masked by poor Salsa failure modes.
Basically, if we can't find a root here, it *must* be a bug. And if we
just silently skip over it, we risk voiding Salsa's purity contract,
leading to more difficult to debug panics.
This did cause one test to fail, but only because the test wasn't
properly setting up roots.
## Summary
Thread visitors through the rest of `apply_type_mapping`: callable and
protocol types.
## Test Plan
Added mdtest that previously stack overflowed.
## Summary
We have the ability to defer type inference of some parts of
definitions, so as to allow us to create a type that may need to be
recursively referenced in those other parts of the definition.
We also have the ability to do type inference in a context where all
name resolution should be deferred (that is, names should be looked up
from all-reachable-definitions rather than from the location of use.)
This is used for all annotations in stubs, or if `from __future__ import
annotations` is active.
Previous to this PR, these two concepts were linked: deferred-inference
always implied deferred-name-resolution, though we also supported
deferred-name-resolution without deferred-inference, via
`DeferredExpressionState`.
For the upcoming `typing.TypeAlias` support, I will defer inference of
the entire RHS of the alias (so as to support cycles), but that doesn't
imply deferred name resolution; at runtime, the RHS of a name annotated
as `typing.TypeAlias` is executed eagerly.
So this PR fully de-couples the two concepts, instead explicitly setting
the `DeferredExpressionState` in those cases where we should defer name
resolution.
It also fixes a long-standing related bug, where we were deferring name
resolution of all names in class bases, if any of the class bases
contained a stringified annotation.
## Test Plan
Added test that failed before this PR.
## Summary
Fuzzer seed 208 seems to be timing out all fuzzer runs on PRs today.
This has happened on multiple unrelated PRs, as well as on an initial
version of this PR that made a comment-only change in ty and didn't skip
any seeds, so the timeout appears to be consistent in CI, on ty main
branch, as of today, but it started happening due to some change in a
factor outside ty; not sure what.
I checked the code generated for seed 208 locally, and it takes about
30s to check on current ty main branch. This is slow for a fuzzer seed,
but shouldn't be slow enough to make it time out after 20min in CI (even
accounting for GH runners being slower than my laptop.)
I tried to bisect the slowness of checking that code locally, but I
didn't go back far enough to find the change that made it slow. In fact
it seems like it became significantly faster in the last few days (on an
older checkout I had to stop it after several minutes.) So whatever the
cause of the slowness, it's not a recent change in ty.
I don't want to rabbit-hole on this right now (fuzzer-discovered issues
are lower-priority than real-world-code issues), and need a working CI,
so skip this seed for now until we can investigate it.
## Test Plan
CI. This PR contains a no-op (comment) change in ty, so that the fuzz
test is triggered in CI and we can verify it now works (as well as
verify, on the previous commit, that the fuzzer job is timing out on
that seed, even with just a no-op change in ty.)
Reverts astral-sh/ruff#20156. As @sharkdp noted in his post-merge
review, there were several issues with that PR that I didn't spot before
merging — but I'm out for four days now, and would rather not leave
things in an inconsistent state for that long. I'll revisit this on
Wednesday.
## Summary
These projects all check successfully now.
(Pandas still takes 9s, as the comment in `bad.txt` said, but I don't
think this is slow enough to exclude it; mypy-primer overall still runs
in 4 minutes, faster than e.g. the test suite on Windows.)
## Test Plan
mypy-primer CI.
## Summary
This error is about assigning to attributes rather than reading
attributes, so I think `invalid-assignment` makes more sense than
`invalid-attribute-access`
## Test Plan
existing mdtests updated
## Summary
In `is_disjoint_from_impl`, we should unpack type aliases before we
check `TypedDict`. This change probably doesn't have any visible effect
until we have a more discriminating implementation of disjointness for
`TypedDict`, but making the change now can avoid some confusion/bugs in
future.
In `type_ordering.rs`, we should order `TypedDict` near more similar
types, and leave Union/Intersection together at the end of the list.
This is not necessary for correctness, but it's more consistent and it
could have saved me some confusion trying to figure out why I was only
getting an unreachable panic when my code example included a `TypedDict`
type.
## Test Plan
None besides existing tests.
## Summary
Now that we have `Type::TypeAlias`, which can wrap a union, and the
possibility of unions including non-unpacked type aliases (which is
necessary to support recursive type aliases), we can no longer assume in
`UnionType::normalized_impl` that normalizing each element of an
existing union will result in a set of elements that we can order and
then place raw into `UnionType` to create a normalized union. It's now
possible for those elements to themselves include union types (unpacked
from an alias). So instead, we need to feed those elements into the full
`UnionBuilder` (with alias-unpacking turned on) to flatten/normalize
them, and then order them.
## Test Plan
Added mdtest.
---------
Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>
## Summary
This PR fixes various TODOs around overload call when a variadic
argument is used.
The reason this bug existed is because the specialization wouldn't
account for unpacking the type of the variadic argument.
This is fixed by expanding `MatchedArgument` to contain the type of that
argument _only_ when it is a variadic argument. The reason is that
there's a split for when the argument type is inferred -- the
non-variadic arguments are inferred using `infer_argument_types` _after_
parameter matching while the variadic argument type is inferred _during_
the parameter matching. And, the `MatchedArgument` is populated _during_
parameter matching which means the unpacking would need to happen during
parameter matching.
This split seems a bit inconsistent but I don't want to spend a lot of
time on trying to merge them such that all argument type inference
happens in a single place. I might look into it while adding support for
`**kwargs`.
## Test Plan
Update existing tests by resolving the todos.
The ecosystem changes looks correct to me except for the `slice` call
but it seems that it's unrelated to this PR as we infer `slice[Any, Any,
Any]` for a `slice(1, 2, 3)` call on `main` as well
([playground](https://play.ty.dev/9eacce00-c7d5-4dd5-a932-4265cb2bb4f6)).
This PR adds an implementation of constraint sets.
An individual constraint restricts the specialization of a single
typevar to be within a particular lower and upper bound: the typevar can
only specialize to types that are a supertype of the lower bound, and a
subtype of the upper bound. (Note that lower and upper bounds are fully
static; we take the bottom and top materializations of the bounds to
remove any gradual forms if needed.) Either bound can be “closed” (where
the bound is a valid specialization), or “open” (where it is not).
You can then build up more complex constraint sets using union,
intersection, and negation operations. We use a disjunctive normal form
(DNF) representation, just like we do for types: a _constraint set_ is
the union of zero or more _clauses_, each of which is the intersection
of zero or more individual constraints. Note that the constraint set
that contains no clauses is never satisfiable (`⋃ {} = 0`); and the
constraint set that contains a single clause, which contains no
constraints, is always satisfiable (`⋃ {⋂ {}} = 1`).
One thing to note is that this PR does not change the logic of the
actual assignability checks, and in particular, we still aren't ever
trying to create an "individual constraint" that constrains a typevar.
Technically we're still operating only on `bool`s, since we only ever
instantiate `C::always_satisfiable` (i.e., `true`) and
`C::unsatisfiable` (i.e., `false`) in the `has_relation_to` methods. So
if you thought that #19838 introduced an unnecessarily complex stand-in
for `bool`, well here you go, this one is worse! (But still seemingly
not yielding a performance regression!) The next PR in this series,
#20093, is where we will actually create some non-trivial constraint
sets and use them in anger.
That said, the PR does go ahead and update the assignability checks to
use the new `ConstraintSet` type instead of `bool`. That part is fairly
straightforward since we had already updated the assignability checks to
use the `Constraints` trait; we just have to actively choose a different
impl type. (For the `is_whatever` variants, which still return a `bool`,
we have to convert the constraint set, but the explicit
`is_always_satisfiable` calls serve as nice documentation of our
intent.)
---------
Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>
Co-authored-by: Carl Meyer <carl@astral.sh>
This is a variant of #20076 that moves some complexity out of
`apply_type_mapping_impl` in `generics.rs`. The tradeoff is that now
every place that applies `TypeMapping::Specialization` must take care to
call `.materialize()` afterwards. (A previous version of this didn't
work because I had missed a spot where I had to call `.materialize()`.)
@carljm as asked in
https://github.com/astral-sh/ruff/pull/20076#discussion_r2305385298 .
## Summary
Decrease the maximum number of literals in a union before we collapse to
the supertype. The better fix for this will be
https://github.com/astral-sh/ty/issues/957, but it is very tempting to
solve this for now by simply decreasing the limit by one, to get below
the salsa limit of 200.
closes https://github.com/astral-sh/ty/issues/660
## Test Plan
Added a regression test that would previously lead to a "too many cycle
iterations" panic.
## Summary
With this PR, we stop performing boundness analysis for implicit
instance attributes:
```py
class C:
def __init__(self):
if False:
self.x = 1
C().x # would previously show an error, with this PR we pretend the attribute exists
```
This PR is potentially just a temporary measure until we find a better
fix. But I have already invested a lot of time trying to find the root
cause of https://github.com/astral-sh/ty/issues/758 (and [this
example](https://github.com/astral-sh/ty/issues/758#issuecomment-3206108262),
which I'm not entirely sure is related) and I still don't understand
what is going on. This PR fixes the performance problems in both of
these problems (in a rather crude way).
The impact of the proposed change on the ecosystem is small, and the
three new diagnostics are arguably true positives (previously hidden
because we considered the code unreachable, based on e.g. `assert`ions
that depended on implicit instance attributes). So this seems like a
reasonable fix for now.
Note that we still support cases like these:
```py
class D:
if False: # or any other expression that statically evaluates to `False`
x: int = 1
D().x # still an error
class E:
if False: # or any other expression that statically evaluates to `False`
def f(self):
self.x = 1
E().x # still an error
```
closes https://github.com/astral-sh/ty/issues/758
## Test Plan
Updated tests, benchmark results
## Summary
closes https://github.com/astral-sh/ty/issues/692
If the expression (or any child expressions) is not definitely bound the
reachability constraint evaluation is determined as ambiguous.
This fixes the infinite cycles panic in the following code:
```py
from typing import Literal
class Toggle:
def __init__(self: "Toggle"):
if not self.x:
self.x: Literal[True] = True
```
Credit of this solution is for David.
## Test Plan
- Added a test case with too many cycle iterations panic.
- Previous tests.
---------
Co-authored-by: David Peter <mail@david-peter.de>
Part of #994. This adds a new field to the Specialization struct to
record when we're dealing with the top or bottom materialization of an
invariant generic. It also implements subtyping and assignability for
these objects.
Next planned steps after this is done are to implement other operations
on top/bottom materializations; probably attribute access is an
important one.
---------
Co-authored-by: Carl Meyer <carl@astral.sh>
There are some situations that we have a confusing diagnostics due to
identical class names.
## Class with same name from different modules
```python
import pandas
import polars
df: pandas.DataFrame = polars.DataFrame()
```
This yields the following error:
**Actual:**
error: [invalid-assignment] "Object of type `DataFrame` is not
assignable to `DataFrame`"
**Expected**:
error: [invalid-assignment] "Object of type `polars.DataFrame` is not
assignable to `pandas.DataFrame`"
## Nested classes
```python
from enum import Enum
class A:
class B(Enum):
ACTIVE = "active"
INACTIVE = "inactive"
class C:
class B(Enum):
ACTIVE = "active"
INACTIVE = "inactive"
```
**Actual**:
error: [invalid-assignment] "Object of type `Literal[B.ACTIVE]` is not
assignable to `B`"
**Expected**:
error: [invalid-assignment] "Object of type
`Literal[my_module.C.B.ACTIVE]` is not assignable to `my_module.A.B`"
## Solution
In this MR we added an heuristics to detect when to use a fully
qualified name:
- There is an invalid assignment and;
- They are two different classes and;
- They have the same name
The fully qualified name always includes:
- module name
- nested classes name
- actual class name
There was no `QualifiedDisplay` so I had to implement it from scratch.
I'm very new to the codebase, so I might have done things inefficiently,
so I appreciate feedback.
Should we pre-compute the fully qualified name or do it on demand?
## Not implemented
### Function-local classes
Should we approach this in a different PR?
**Example**:
```python
# t.py
from __future__ import annotations
def function() -> A:
class A:
pass
return A()
class A:
pass
a: A = function()
```
#### mypy
```console
t.py:8: error: Incompatible return value type (got "t.A@5", expected "t.A") [return-value]
```
From my testing the 5 in `A@5` comes from the like number.
#### ty
```console
error[invalid-return-type]: Return type does not match returned value
--> t.py:4:19
|
4 | def function() -> A:
| - Expected `A` because of return type
5 | class A:
6 | pass
7 |
8 | return A()
| ^^^ expected `A`, found `A`
|
info: rule `invalid-return-type` is enabled by default
```
Fixes https://github.com/astral-sh/ty/issues/848
---------
Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>
Co-authored-by: Carl Meyer <carl@astral.sh>
## Summary
While looking at some logging output that I added to
`ReachabilityConstraintBuilder::add_and_constraint` in order to debug
https://github.com/astral-sh/ty/issues/1091, I noticed that it seemed to
suggest that the TDD was built in an imbalanced way for code like the
following, where we have a sequence of non-nested `if` conditions:
```py
def f(t1, t2, t3, t4, …):
x = 0
if t1:
x = 1
if t2:
x = 2
if t3:
x = 3
if t4:
x = 4
…
```
To understand this a bit better, I added some code to the
`ReachabilityConstraintBuilder` to render the resulting TDD. On `main`,
we get a tree that looks like the following, where you can see a pattern
of N sub-trees that grow linearly with N (number of `if` statements).
This results in an overall tree structure that has N² nodes (see graph
below):
<img alt="normal order"
src="https://github.com/user-attachments/assets/aab40ce9-e82a-4fcd-823a-811f05f15f66"
/>
If we zoom in to one of these subgraphs, we can see what the problem is.
When we add new constraints that represent combinations like `t1 AND ~t2
AND ~t3 AND t4 AND …`, they start with the evaluation of "early"
conditions (`t1`, `t2`, …). This means that we have to create new
subgraphs for each new `if` condition because there is little sharing
with the previous structure. We evaluate the Boolean condition in a
right-associative way: `t1 AND (~t2 AND (~t3 AND t4)))`:
<img width="500" align="center"
src="https://github.com/user-attachments/assets/31ea7182-9e00-4975-83df-d980464f545d"
/>
If we change the ordering of TDD atoms, we can change that to a
left-associative evaluation: `(((t1 AND ~t2) AND ~t3) AND t4) …`. This
means that we can re-use previous subgraphs `(t1 AND ~t2)`, which
results in a much more compact graph structure overall (note how "late"
conditions are now at the top, and "early" conditions are further down
in the graph):
<img alt="reverse order"
src="https://github.com/user-attachments/assets/96a6b7c1-3d35-4192-a917-0b2d24c6b144"
/>
If we count the number of TDD nodes for a growing number if `if`
statements, we can see that this change results in a slower growth. It's
worth noting that the growth is still superlinear, though:
<img width="800" height="600" alt="plot"
src="https://github.com/user-attachments/assets/22e8394f-e74e-4a9e-9687-0d41f94f2303"
/>
On the actual code from the referenced ticket (the `t_main.py` file
reduced to its main function, with the main function limited to 2000
lines instead of 11000 to allow the version on `main` to run to
completion), the effect is much more dramatic. Instead of 26 million TDD
nodes (`main`), we now only create 250 thousand (this branch), which is
slightly less than 1%.
The change in this PR allows us to build the semantic index and
type-check the problematic `t_main.py` file in
https://github.com/astral-sh/ty/issues/1091 in 9 seconds. This is still
not great, but an obvious improvement compared to running out of memory
after *minutes* of execution.
An open question remains whether this change is beneficial for all kinds
of code patterns, or just this linear sequence of `if` statements. It
does not seem unreasonable to think that referring to "earlier"
conditions is generally a good idea, but I learned from Doug that it's
generally not possible to find a TDD-construction heuristic that is
non-pathological for all kinds of inputs. Fortunately, it seems like
this change here results in performance improvements across *all of our
benchmarks*, which should increase the confidence in this change:
| Benchmark | Improvement |
|---------------------|-------------------------|
| hydra-zen | +13% |
| DateType | +5% |
| sympy (walltime) | +4% |
| attrs | +4% |
| pydantic (walltime) | +2% |
| pandas (walltime) | +2% |
| altair (walltime) | +2% |
| static-frame | +2% |
| anyio | +1% |
| freqtrade | +1% |
| colour-science | +1% |
| tanjun | +1% |
closes https://github.com/astral-sh/ty/issues/1091
---------
Co-authored-by: Douglas Creager <dcreager@dcreager.net>
## Summary
Properly preserve type qualifiers when accessing attributes on unions
and intersections. This is a prerequisite for
https://github.com/astral-sh/ruff/pull/19579.
Also fix a completely wrong implementation of
`map_with_boundness_and_qualifiers`. It now closely follows
`map_with_boundness` (just above).
## Test Plan
I thought about it, but didn't find any easy way to test this. This only
affected `Type::member`. Things like validation of attribute writes
(where type qualifiers like `ClassVar` and `Final` are important) were
already handling things correctly.
