From 7a8ffed28d797d93e36a66b79f062d154476a4b6 Mon Sep 17 00:00:00 2001 From: Alex Waygood Date: Sun, 14 Dec 2025 19:26:48 +0000 Subject: [PATCH] several improvements --- crates/ty/docs/rules.md | 193 ++++++++---------- .../diagnostics/invalid_type_param_order.md | 29 --- .../invalid_type_parameter_order.md | 43 ++++ .../mdtest/generics/legacy/paramspec.md | 2 +- ...nvalid_Type_Param_O…_(8ff6f101710809cb).snap | 63 ------ ...nvalid_Order_of_Leg…_(eaa359e8d6b3031d).snap | 190 +++++++++++++++++ .../src/types/diagnostic.rs | 121 +++++++---- .../src/types/infer/builder.rs | 80 +++++--- 8 files changed, 449 insertions(+), 272 deletions(-) delete mode 100644 crates/ty_python_semantic/resources/mdtest/diagnostics/invalid_type_param_order.md create mode 100644 crates/ty_python_semantic/resources/mdtest/diagnostics/invalid_type_parameter_order.md delete mode 100644 crates/ty_python_semantic/resources/mdtest/snapshots/invalid_type_param_o…_-_Invalid_Type_Param_O…_(8ff6f101710809cb).snap create mode 100644 crates/ty_python_semantic/resources/mdtest/snapshots/invalid_type_paramet…_-_Invalid_Order_of_Leg…_(eaa359e8d6b3031d).snap diff --git a/crates/ty/docs/rules.md b/crates/ty/docs/rules.md index 86e1d127a8..8b35be52a6 100644 --- a/crates/ty/docs/rules.md +++ b/crates/ty/docs/rules.md @@ -39,7 +39,7 @@ def test(): -> "int": Default level: error · Added in 0.0.1-alpha.1 · Related issues · -View source +View source @@ -63,7 +63,7 @@ Calling a non-callable object will raise a `TypeError` at runtime. Default level: error · Added in 0.0.1-alpha.1 · Related issues · -View source +View source @@ -95,7 +95,7 @@ f(int) # error Default level: error · Added in 0.0.1-alpha.1 · Related issues · -View source +View source @@ -126,7 +126,7 @@ a = 1 Default level: error · Added in 0.0.1-alpha.1 · Related issues · -View source +View source @@ -158,7 +158,7 @@ class C(A, B): ... Default level: error · Added in 0.0.1-alpha.1 · Related issues · -View source +View source @@ -190,7 +190,7 @@ class B(A): ... Default level: error · Preview (since 1.0.0) · Related issues · -View source +View source @@ -218,7 +218,7 @@ type B = A Default level: error · Added in 0.0.1-alpha.1 · Related issues · -View source +View source @@ -245,7 +245,7 @@ class B(A, A): ... Default level: error · Added in 0.0.1-alpha.12 · Related issues · -View source +View source @@ -357,7 +357,7 @@ def test(): -> "Literal[5]": Default level: error · Added in 0.0.1-alpha.1 · Related issues · -View source +View source @@ -387,7 +387,7 @@ class C(A, B): ... Default level: error · Added in 0.0.1-alpha.1 · Related issues · -View source +View source @@ -413,7 +413,7 @@ t[3] # IndexError: tuple index out of range Default level: error · Added in 0.0.1-alpha.12 · Related issues · -View source +View source @@ -502,7 +502,7 @@ an atypical memory layout. Default level: error · Added in 0.0.1-alpha.1 · Related issues · -View source +View source @@ -529,7 +529,7 @@ func("foo") # error: [invalid-argument-type] Default level: error · Added in 0.0.1-alpha.1 · Related issues · -View source +View source @@ -557,7 +557,7 @@ a: int = '' Default level: error · Added in 0.0.1-alpha.1 · Related issues · -View source +View source @@ -591,7 +591,7 @@ C.instance_var = 3 # error: Cannot assign to instance variable Default level: error · Added in 0.0.1-alpha.19 · Related issues · -View source +View source @@ -627,7 +627,7 @@ asyncio.run(main()) Default level: error · Added in 0.0.1-alpha.1 · Related issues · -View source +View source @@ -651,7 +651,7 @@ class A(42): ... # error: [invalid-base] Default level: error · Added in 0.0.1-alpha.1 · Related issues · -View source +View source @@ -678,7 +678,7 @@ with 1: Default level: error · Added in 0.0.1-alpha.1 · Related issues · -View source +View source @@ -707,7 +707,7 @@ a: str Default level: error · Added in 0.0.1-alpha.1 · Related issues · -View source +View source @@ -751,7 +751,7 @@ except ZeroDivisionError: Default level: error · Added in 0.0.1-alpha.28 · Related issues · -View source +View source @@ -793,7 +793,7 @@ class D(A): Default level: error · Added in 0.0.1-alpha.35 · Related issues · -View source +View source @@ -837,7 +837,7 @@ class NonFrozenChild(FrozenBase): # Error raised here Default level: error · Added in 0.0.1-alpha.1 · Related issues · -View source +View source @@ -848,16 +848,21 @@ Checks for the creation of invalid generic classes **Why is this bad?** There are several requirements that you must follow when defining a generic class. +Many of these result in `TypeError` being raised at runtime if they are violated. **Examples** ```python -from typing import Generic, TypeVar +from typing_extensions import Generic, TypeVar -T = TypeVar("T") # okay +T = TypeVar("T") +U = TypeVar("U", default=int) # error: class uses both PEP-695 syntax and legacy syntax class C[U](Generic[T]): ... + +# error: type parameter with default comes before type parameter without default +class D(Generic[U, T]): ... ``` **References** @@ -870,7 +875,7 @@ class C[U](Generic[T]): ... Default level: error · Added in 0.0.1-alpha.17 · Related issues · -View source +View source @@ -909,7 +914,7 @@ carol = Person(name="Carol", age=25) # typo! Default level: error · Added in 0.0.1-alpha.1 · Related issues · -View source +View source @@ -944,7 +949,7 @@ def f(t: TypeVar("U")): ... Default level: error · Added in 0.0.1-alpha.1 · Related issues · -View source +View source @@ -978,7 +983,7 @@ class B(metaclass=f): ... Default level: error · Added in 0.0.1-alpha.20 · Related issues · -View source +View source @@ -1085,7 +1090,7 @@ Correct use of `@override` is enforced by ty's `invalid-explicit-override` rule. Default level: error · Added in 0.0.1-alpha.19 · Related issues · -View source +View source @@ -1139,7 +1144,7 @@ AttributeError: Cannot overwrite NamedTuple attribute _asdict Default level: error · Preview (since 1.0.0) · Related issues · -View source +View source @@ -1169,7 +1174,7 @@ Baz = NewType("Baz", int | str) # error: invalid base for `typing.NewType` Default level: error · Added in 0.0.1-alpha.1 · Related issues · -View source +View source @@ -1219,7 +1224,7 @@ def foo(x: int) -> int: ... Default level: error · Added in 0.0.1-alpha.1 · Related issues · -View source +View source @@ -1245,7 +1250,7 @@ def f(a: int = ''): ... Default level: error · Added in 0.0.1-alpha.1 · Related issues · -View source +View source @@ -1276,7 +1281,7 @@ P2 = ParamSpec("S2") # error: ParamSpec name must match the variable it's assig Default level: error · Added in 0.0.1-alpha.1 · Related issues · -View source +View source @@ -1310,7 +1315,7 @@ TypeError: Protocols can only inherit from other protocols, got Default level: error · Added in 0.0.1-alpha.1 · Related issues · -View source +View source @@ -1359,7 +1364,7 @@ def g(): Default level: error · Added in 0.0.1-alpha.1 · Related issues · -View source +View source @@ -1384,7 +1389,7 @@ def func() -> int: Default level: error · Added in 0.0.1-alpha.1 · Related issues · -View source +View source @@ -1442,7 +1447,7 @@ TODO #14889 Default level: error · Added in 0.0.1-alpha.6 · Related issues · -View source +View source @@ -1469,7 +1474,7 @@ NewAlias = TypeAliasType(get_name(), int) # error: TypeAliasType name mus Default level: error · Added in 0.0.1-alpha.29 · Related issues · -View source +View source @@ -1516,7 +1521,7 @@ Bar[int] # error: too few arguments Default level: error · Added in 0.0.1-alpha.1 · Related issues · -View source +View source @@ -1546,7 +1551,7 @@ TYPE_CHECKING = '' Default level: error · Added in 0.0.1-alpha.1 · Related issues · -View source +View source @@ -1576,7 +1581,7 @@ b: Annotated[int] # `Annotated` expects at least two arguments Default level: error · Added in 0.0.1-alpha.11 · Related issues · -View source +View source @@ -1610,7 +1615,7 @@ f(10) # Error Default level: error · Added in 0.0.1-alpha.11 · Related issues · -View source +View source @@ -1638,47 +1643,13 @@ class C: def f(self) -> TypeIs[int]: ... # Error, only positional argument expected is `self` ``` -## `invalid-type-param-order` - - -Default level: error · -Added in 0.0.1-alpha.1 · -Related issues · -View source - - - -**What it does** - -Checks for type parameters without defaults that come after type parameters with defaults. - -**Why is this bad?** - -Type parameters without defaults must come before type parameters with defaults. - -**Example** - - -```python -from typing import Generic, TypeVar - -T = TypeVar("T") -U = TypeVar("U") -# Error: T has no default but comes after U which has a default -class Foo(Generic[U = int, T]): ... -``` - -**References** - -- [PEP 696: Type defaults for type parameters](https://peps.python.org/pep-0696/) - ## `invalid-type-variable-constraints` Default level: error · Added in 0.0.1-alpha.1 · Related issues · -View source +View source @@ -1713,7 +1684,7 @@ T = TypeVar('T', bound=str) # valid bound TypeVar Default level: error · Added in 0.0.1-alpha.1 · Related issues · -View source +View source @@ -1738,7 +1709,7 @@ func() # TypeError: func() missing 1 required positional argument: 'x' Default level: error · Added in 0.0.1-alpha.20 · Related issues · -View source +View source @@ -1771,7 +1742,7 @@ alice["age"] # KeyError Default level: error · Added in 0.0.1-alpha.1 · Related issues · -View source +View source @@ -1800,7 +1771,7 @@ func("string") # error: [no-matching-overload] Default level: error · Added in 0.0.1-alpha.1 · Related issues · -View source +View source @@ -1824,7 +1795,7 @@ Subscripting an object that does not support it will raise a `TypeError` at runt Default level: error · Added in 0.0.1-alpha.1 · Related issues · -View source +View source @@ -1850,7 +1821,7 @@ for i in 34: # TypeError: 'int' object is not iterable Default level: error · Added in 0.0.1-alpha.29 · Related issues · -View source +View source @@ -1883,7 +1854,7 @@ class B(A): Default level: error · Added in 0.0.1-alpha.1 · Related issues · -View source +View source @@ -1910,7 +1881,7 @@ f(1, x=2) # Error raised here Default level: error · Added in 0.0.1-alpha.22 · Related issues · -View source +View source @@ -1968,7 +1939,7 @@ def test(): -> "int": Default level: error · Added in 0.0.1-alpha.1 · Related issues · -View source +View source @@ -1998,7 +1969,7 @@ static_assert(int(2.0 * 3.0) == 6) # error: does not have a statically known tr Default level: error · Added in 0.0.1-alpha.1 · Related issues · -View source +View source @@ -2027,7 +1998,7 @@ class B(A): ... # Error raised here Default level: error · Preview (since 0.0.1-alpha.30) · Related issues · -View source +View source @@ -2061,7 +2032,7 @@ class F(NamedTuple): Default level: error · Added in 0.0.1-alpha.1 · Related issues · -View source +View source @@ -2088,7 +2059,7 @@ f("foo") # Error raised here Default level: error · Added in 0.0.1-alpha.1 · Related issues · -View source +View source @@ -2116,7 +2087,7 @@ def _(x: int): Default level: error · Added in 0.0.1-alpha.1 · Related issues · -View source +View source @@ -2162,7 +2133,7 @@ class A: Default level: error · Added in 0.0.1-alpha.1 · Related issues · -View source +View source @@ -2189,7 +2160,7 @@ f(x=1, y=2) # Error raised here Default level: error · Added in 0.0.1-alpha.1 · Related issues · -View source +View source @@ -2217,7 +2188,7 @@ A().foo # AttributeError: 'A' object has no attribute 'foo' Default level: error · Added in 0.0.1-alpha.1 · Related issues · -View source +View source @@ -2242,7 +2213,7 @@ import foo # ModuleNotFoundError: No module named 'foo' Default level: error · Added in 0.0.1-alpha.1 · Related issues · -View source +View source @@ -2267,7 +2238,7 @@ print(x) # NameError: name 'x' is not defined Default level: error · Added in 0.0.1-alpha.1 · Related issues · -View source +View source @@ -2304,7 +2275,7 @@ b1 < b2 < b1 # exception raised here Default level: error · Added in 0.0.1-alpha.1 · Related issues · -View source +View source @@ -2332,7 +2303,7 @@ A() + A() # TypeError: unsupported operand type(s) for +: 'A' and 'A' Default level: error · Added in 0.0.1-alpha.1 · Related issues · -View source +View source @@ -2357,7 +2328,7 @@ l[1:10:0] # ValueError: slice step cannot be zero Default level: warn · Added in 0.0.1-alpha.20 · Related issues · -View source +View source @@ -2398,7 +2369,7 @@ class SubProto(BaseProto, Protocol): Default level: warn · Added in 0.0.1-alpha.16 · Related issues · -View source +View source @@ -2486,7 +2457,7 @@ a = 20 / 0 # type: ignore Default level: warn · Added in 0.0.1-alpha.22 · Related issues · -View source +View source @@ -2514,7 +2485,7 @@ A.c # AttributeError: type object 'A' has no attribute 'c' Default level: warn · Added in 0.0.1-alpha.22 · Related issues · -View source +View source @@ -2546,7 +2517,7 @@ A()[0] # TypeError: 'A' object is not subscriptable Default level: warn · Added in 0.0.1-alpha.22 · Related issues · -View source +View source @@ -2578,7 +2549,7 @@ from module import a # ImportError: cannot import name 'a' from 'module' Default level: warn · Added in 0.0.1-alpha.1 · Related issues · -View source +View source @@ -2605,7 +2576,7 @@ cast(int, f()) # Redundant Default level: warn · Added in 0.0.1-alpha.1 · Related issues · -View source +View source @@ -2629,7 +2600,7 @@ reveal_type(1) # NameError: name 'reveal_type' is not defined Default level: warn · Added in 0.0.1-alpha.15 · Related issues · -View source +View source @@ -2687,7 +2658,7 @@ def g(): Default level: warn · Added in 0.0.1-alpha.7 · Related issues · -View source +View source @@ -2726,7 +2697,7 @@ class D(C): ... # error: [unsupported-base] Default level: warn · Added in 0.0.1-alpha.22 · Related issues · -View source +View source @@ -2789,7 +2760,7 @@ def foo(x: int | str) -> int | str: Default level: ignore · Preview (since 0.0.1-alpha.1) · Related issues · -View source +View source @@ -2813,7 +2784,7 @@ Dividing by zero raises a `ZeroDivisionError` at runtime. Default level: ignore · Added in 0.0.1-alpha.1 · Related issues · -View source +View source diff --git a/crates/ty_python_semantic/resources/mdtest/diagnostics/invalid_type_param_order.md b/crates/ty_python_semantic/resources/mdtest/diagnostics/invalid_type_param_order.md deleted file mode 100644 index 2b5d956f9b..0000000000 --- a/crates/ty_python_semantic/resources/mdtest/diagnostics/invalid_type_param_order.md +++ /dev/null @@ -1,29 +0,0 @@ -# Invalid Type Param Order - - - -```toml -[environment] -python-version = "3.13" -``` - -```py -from typing import TypeVar, Generic - -T1 = TypeVar("T1", default=int) -T2 = TypeVar("T2") -T3 = TypeVar("T3") -DefaultStrT = TypeVar("DefaultStrT", default=str) - -class SubclassMe(Generic[T1, DefaultStrT]): - x: DefaultStrT - -class Baz(SubclassMe[int, DefaultStrT]): - pass - -class Foo(Generic[T1, T2]): # error: [invalid-type-param-order] - pass - -class Bar(Generic[T2, T1, T3]): # error: [invalid-type-param-order] - pass -``` diff --git a/crates/ty_python_semantic/resources/mdtest/diagnostics/invalid_type_parameter_order.md b/crates/ty_python_semantic/resources/mdtest/diagnostics/invalid_type_parameter_order.md new file mode 100644 index 0000000000..705ceae6b6 --- /dev/null +++ b/crates/ty_python_semantic/resources/mdtest/diagnostics/invalid_type_parameter_order.md @@ -0,0 +1,43 @@ +# Invalid Order of Legacy Type Parameters + + + +```toml +[environment] +python-version = "3.13" +``` + +```py +from typing import TypeVar, Generic, Protocol + +T1 = TypeVar("T1", default=int) + +T2 = TypeVar("T2") +T3 = TypeVar("T3") + +DefaultStrT = TypeVar("DefaultStrT", default=str) + +class SubclassMe(Generic[T1, DefaultStrT]): + x: DefaultStrT + +class Baz(SubclassMe[int, DefaultStrT]): + pass + +# error: [invalid-generic-class] "Type parameter `T2` without a default cannot follow earlier parameter `T1` with a default" +class Foo(Generic[T1, T2]): + pass + +class Bar(Generic[T2, T1, T3]): # error: [invalid-generic-class] + pass + +class Spam(Generic[T1, T2, DefaultStrT, T3]): # error: [invalid-generic-class] + pass + +class Ham(Protocol[T1, T2, DefaultStrT, T3]): # error: [invalid-generic-class] + pass + +class VeryBad( + Protocol[T1, T2, DefaultStrT, T3], # error: [invalid-generic-class] + Generic[T1, T2, DefaultStrT, T3], +): ... +``` diff --git a/crates/ty_python_semantic/resources/mdtest/generics/legacy/paramspec.md b/crates/ty_python_semantic/resources/mdtest/generics/legacy/paramspec.md index 00f50240e4..5e3cbe3888 100644 --- a/crates/ty_python_semantic/resources/mdtest/generics/legacy/paramspec.md +++ b/crates/ty_python_semantic/resources/mdtest/generics/legacy/paramspec.md @@ -425,7 +425,7 @@ reveal_type(p3.attr1) # revealed: (int, /) -> None reveal_type(p3.attr2) # revealed: (str, /) -> None # Un-ordered type variables as the default of `PAnother` is `P` -class ParamSpecWithDefault5(Generic[PAnother, P]): # error: [invalid-type-param-order] +class ParamSpecWithDefault5(Generic[PAnother, P]): # error: [invalid-generic-class] attr: Callable[PAnother, None] # TODO: error diff --git a/crates/ty_python_semantic/resources/mdtest/snapshots/invalid_type_param_o…_-_Invalid_Type_Param_O…_(8ff6f101710809cb).snap b/crates/ty_python_semantic/resources/mdtest/snapshots/invalid_type_param_o…_-_Invalid_Type_Param_O…_(8ff6f101710809cb).snap deleted file mode 100644 index 74cc600ed1..0000000000 --- a/crates/ty_python_semantic/resources/mdtest/snapshots/invalid_type_param_o…_-_Invalid_Type_Param_O…_(8ff6f101710809cb).snap +++ /dev/null @@ -1,63 +0,0 @@ ---- -source: crates/ty_test/src/lib.rs -expression: snapshot ---- ---- -mdtest name: invalid_type_param_order.md - Invalid Type Param Order -mdtest path: crates/ty_python_semantic/resources/mdtest/diagnostics/invalid_type_param_order.md ---- - -# Python source files - -## mdtest_snippet.py - -``` - 1 | from typing import TypeVar, Generic - 2 | - 3 | T1 = TypeVar("T1", default=int) - 4 | T2 = TypeVar("T2") - 5 | T3 = TypeVar("T3") - 6 | DefaultStrT = TypeVar("DefaultStrT", default=str) - 7 | - 8 | class SubclassMe(Generic[T1, DefaultStrT]): - 9 | x: DefaultStrT -10 | -11 | class Baz(SubclassMe[int, DefaultStrT]): -12 | pass -13 | -14 | class Foo(Generic[T1, T2]): # error: [invalid-type-param-order] -15 | pass -16 | -17 | class Bar(Generic[T2, T1, T3]): # error: [invalid-type-param-order] -18 | pass -``` - -# Diagnostics - -``` -error[invalid-type-param-order]: Type parameter T2 without a default follows type parameter with a default - --> src/mdtest_snippet.py:14:7 - | -12 | pass -13 | -14 | class Foo(Generic[T1, T2]): # error: [invalid-type-param-order] - | ^^^^^^^^^^^^^^^^^^^^ -15 | pass - | -info: rule `invalid-type-param-order` is enabled by default - -``` - -``` -error[invalid-type-param-order]: Type parameter T3 without a default follows type parameter with a default - --> src/mdtest_snippet.py:17:7 - | -15 | pass -16 | -17 | class Bar(Generic[T2, T1, T3]): # error: [invalid-type-param-order] - | ^^^^^^^^^^^^^^^^^^^^^^^^ -18 | pass - | -info: rule `invalid-type-param-order` is enabled by default - -``` diff --git a/crates/ty_python_semantic/resources/mdtest/snapshots/invalid_type_paramet…_-_Invalid_Order_of_Leg…_(eaa359e8d6b3031d).snap b/crates/ty_python_semantic/resources/mdtest/snapshots/invalid_type_paramet…_-_Invalid_Order_of_Leg…_(eaa359e8d6b3031d).snap new file mode 100644 index 0000000000..290fbb0ae0 --- /dev/null +++ b/crates/ty_python_semantic/resources/mdtest/snapshots/invalid_type_paramet…_-_Invalid_Order_of_Leg…_(eaa359e8d6b3031d).snap @@ -0,0 +1,190 @@ +--- +source: crates/ty_test/src/lib.rs +expression: snapshot +--- +--- +mdtest name: invalid_type_parameter_order.md - Invalid Order of Legacy Type Parameters +mdtest path: crates/ty_python_semantic/resources/mdtest/diagnostics/invalid_type_parameter_order.md +--- + +# Python source files + +## mdtest_snippet.py + +``` + 1 | from typing import TypeVar, Generic, Protocol + 2 | + 3 | T1 = TypeVar("T1", default=int) + 4 | + 5 | T2 = TypeVar("T2") + 6 | T3 = TypeVar("T3") + 7 | + 8 | DefaultStrT = TypeVar("DefaultStrT", default=str) + 9 | +10 | class SubclassMe(Generic[T1, DefaultStrT]): +11 | x: DefaultStrT +12 | +13 | class Baz(SubclassMe[int, DefaultStrT]): +14 | pass +15 | +16 | # error: [invalid-generic-class] "Type parameter `T2` without a default cannot follow earlier parameter `T1` with a default" +17 | class Foo(Generic[T1, T2]): +18 | pass +19 | +20 | class Bar(Generic[T2, T1, T3]): # error: [invalid-generic-class] +21 | pass +22 | +23 | class Spam(Generic[T1, T2, DefaultStrT, T3]): # error: [invalid-generic-class] +24 | pass +25 | +26 | class Ham(Protocol[T1, T2, DefaultStrT, T3]): # error: [invalid-generic-class] +27 | pass +28 | +29 | class VeryBad( +30 | Protocol[T1, T2, DefaultStrT, T3], # error: [invalid-generic-class] +31 | Generic[T1, T2, DefaultStrT, T3], +32 | ): ... +``` + +# Diagnostics + +``` +error[invalid-generic-class]: Type parameters without defaults cannot follow type parameters with defaults + --> src/mdtest_snippet.py:17:19 + | +16 | # error: [invalid-generic-class] "Type parameter `T2` without a default cannot follow earlier parameter `T1` with a default" +17 | class Foo(Generic[T1, T2]): + | ^^^^^^ + | | + | Type variable `T2` does not have a default + | Earlier TypeVar `T1` does +18 | pass + | + ::: src/mdtest_snippet.py:3:1 + | + 1 | from typing import TypeVar, Generic, Protocol + 2 | + 3 | T1 = TypeVar("T1", default=int) + | ------------------------------- `T1` defined here + 4 | + 5 | T2 = TypeVar("T2") + | ------------------ `T2` defined here + 6 | T3 = TypeVar("T3") + | +info: rule `invalid-generic-class` is enabled by default + +``` + +``` +error[invalid-generic-class]: Type parameters without defaults cannot follow type parameters with defaults + --> src/mdtest_snippet.py:20:19 + | +18 | pass +19 | +20 | class Bar(Generic[T2, T1, T3]): # error: [invalid-generic-class] + | ^^^^^^^^^^ + | | + | Type variable `T3` does not have a default + | Earlier TypeVar `T1` does +21 | pass + | + ::: src/mdtest_snippet.py:3:1 + | + 1 | from typing import TypeVar, Generic, Protocol + 2 | + 3 | T1 = TypeVar("T1", default=int) + | ------------------------------- `T1` defined here + 4 | + 5 | T2 = TypeVar("T2") + 6 | T3 = TypeVar("T3") + | ------------------ `T3` defined here + 7 | + 8 | DefaultStrT = TypeVar("DefaultStrT", default=str) + | +info: rule `invalid-generic-class` is enabled by default + +``` + +``` +error[invalid-generic-class]: Type parameters without defaults cannot follow type parameters with defaults + --> src/mdtest_snippet.py:23:20 + | +21 | pass +22 | +23 | class Spam(Generic[T1, T2, DefaultStrT, T3]): # error: [invalid-generic-class] + | ^^^^^^^^^^^^^^^^^^^^^^^ + | | + | Type variables `T2` and `T3` do not have defaults + | Earlier TypeVar `T1` does +24 | pass + | + ::: src/mdtest_snippet.py:3:1 + | + 1 | from typing import TypeVar, Generic, Protocol + 2 | + 3 | T1 = TypeVar("T1", default=int) + | ------------------------------- `T1` defined here + 4 | + 5 | T2 = TypeVar("T2") + | ------------------ `T2` defined here + 6 | T3 = TypeVar("T3") + | +info: rule `invalid-generic-class` is enabled by default + +``` + +``` +error[invalid-generic-class]: Type parameters without defaults cannot follow type parameters with defaults + --> src/mdtest_snippet.py:26:20 + | +24 | pass +25 | +26 | class Ham(Protocol[T1, T2, DefaultStrT, T3]): # error: [invalid-generic-class] + | ^^^^^^^^^^^^^^^^^^^^^^^ + | | + | Type variables `T2` and `T3` do not have defaults + | Earlier TypeVar `T1` does +27 | pass + | + ::: src/mdtest_snippet.py:3:1 + | + 1 | from typing import TypeVar, Generic, Protocol + 2 | + 3 | T1 = TypeVar("T1", default=int) + | ------------------------------- `T1` defined here + 4 | + 5 | T2 = TypeVar("T2") + | ------------------ `T2` defined here + 6 | T3 = TypeVar("T3") + | +info: rule `invalid-generic-class` is enabled by default + +``` + +``` +error[invalid-generic-class]: Type parameters without defaults cannot follow type parameters with defaults + --> src/mdtest_snippet.py:30:14 + | +29 | class VeryBad( +30 | Protocol[T1, T2, DefaultStrT, T3], # error: [invalid-generic-class] + | ^^^^^^^^^^^^^^^^^^^^^^^ + | | + | Type variables `T2` and `T3` do not have defaults + | Earlier TypeVar `T1` does +31 | Generic[T1, T2, DefaultStrT, T3], +32 | ): ... + | + ::: src/mdtest_snippet.py:3:1 + | + 1 | from typing import TypeVar, Generic, Protocol + 2 | + 3 | T1 = TypeVar("T1", default=int) + | ------------------------------- `T1` defined here + 4 | + 5 | T2 = TypeVar("T2") + | ------------------ `T2` defined here + 6 | T3 = TypeVar("T3") + | +info: rule `invalid-generic-class` is enabled by default + +``` diff --git a/crates/ty_python_semantic/src/types/diagnostic.rs b/crates/ty_python_semantic/src/types/diagnostic.rs index 9fc7141057..e136057d45 100644 --- a/crates/ty_python_semantic/src/types/diagnostic.rs +++ b/crates/ty_python_semantic/src/types/diagnostic.rs @@ -30,7 +30,7 @@ use crate::types::{ ProtocolInstanceType, SpecialFormType, SubclassOfInner, Type, TypeContext, binding_type, protocol_class::ProtocolClass, }; -use crate::types::{DataclassFlags, KnownInstanceType, MemberLookupPolicy}; +use crate::types::{DataclassFlags, KnownInstanceType, MemberLookupPolicy, TypeVarInstance}; use crate::{Db, DisplaySettings, FxIndexMap, Module, ModuleName, Program, declare_lint}; use itertools::Itertools; use ruff_db::{ @@ -89,7 +89,6 @@ pub(crate) fn register_lints(registry: &mut LintRegistryBuilder) { registry.register_lint(&INVALID_TYPE_FORM); registry.register_lint(&INVALID_TYPE_GUARD_DEFINITION); registry.register_lint(&INVALID_TYPE_GUARD_CALL); - registry.register_lint(&INVALID_TYPE_PARAM_ORDER); registry.register_lint(&INVALID_TYPE_VARIABLE_CONSTRAINTS); registry.register_lint(&MISSING_ARGUMENT); registry.register_lint(&NO_MATCHING_OVERLOAD); @@ -895,15 +894,20 @@ declare_lint! { /// /// ## Why is this bad? /// There are several requirements that you must follow when defining a generic class. + /// Many of these result in `TypeError` being raised at runtime if they are violated. /// /// ## Examples /// ```python - /// from typing import Generic, TypeVar + /// from typing_extensions import Generic, TypeVar /// - /// T = TypeVar("T") # okay + /// T = TypeVar("T") + /// U = TypeVar("U", default=int) /// /// # error: class uses both PEP-695 syntax and legacy syntax /// class C[U](Generic[T]): ... + /// + /// # error: type parameter with default comes before type parameter without default + /// class D(Generic[U, T]): ... /// ``` /// /// ## References @@ -988,33 +992,6 @@ declare_lint! { } } -declare_lint! { - /// ## What it does - /// Checks for type parameters without defaults that come after type parameters with defaults. - /// - /// ## Why is this bad? - /// Type parameters without defaults must come before type parameters with defaults. - /// - /// ## Example - /// - /// ```python - /// from typing import Generic, TypeVar - /// - /// T = TypeVar("T") - /// U = TypeVar("U") - /// # Error: T has no default but comes after U which has a default - /// class Foo(Generic[U = int, T]): ... - /// ``` - /// - /// ## References - /// - [PEP 696: Type defaults for type parameters](https://peps.python.org/pep-0696/) - pub(crate) static INVALID_TYPE_PARAM_ORDER = { - summary: "detects invalid type parameter order", - status: LintStatus::stable("0.0.1-alpha.1"), - default_level: Level::Error, - } -} - declare_lint! { /// ## What it does /// Checks for the creation of invalid `NewType`s @@ -3726,14 +3703,84 @@ pub(crate) fn report_cannot_pop_required_field_on_typed_dict<'db>( pub(crate) fn report_invalid_type_param_order<'db>( context: &InferContext<'db, '_>, class: ClassLiteral<'db>, - name: &str, + node: &ast::StmtClassDef, + typevar_with_default: TypeVarInstance<'db>, + invalid_later_typevars: &[TypeVarInstance<'db>], ) { - if let Some(builder) = - context.report_lint(&INVALID_TYPE_PARAM_ORDER, class.header_range(context.db())) - { - builder.into_diagnostic(format_args!( - "Type parameter {name} without a default follows type parameter with a default", + let db = context.db(); + + let base_index = class + .explicit_bases(db) + .iter() + .position(|base| { + matches!( + base, + Type::KnownInstance( + KnownInstanceType::SubscriptedProtocol(_) + | KnownInstanceType::SubscriptedGeneric(_) + ) + ) + }) + .expect( + "It should not be possible for a class to have a legacy generic context \ + if it does not inherit from `Protocol[]` or `Generic[]`", + ); + + let base_node = &node.bases()[base_index]; + + let primary_diagnostic_range = base_node + .as_subscript_expr() + .map(|subscript| &*subscript.slice) + .unwrap_or(base_node) + .range(); + + let Some(builder) = context.report_lint(&INVALID_GENERIC_CLASS, primary_diagnostic_range) + else { + return; + }; + + let mut diagnostic = builder.into_diagnostic( + "Type parameters without defaults cannot follow type parameters with defaults", + ); + + diagnostic.set_concise_message(format_args!( + "Type parameter `{}` without a default cannot follow earlier parameter `{}` with a default", + invalid_later_typevars[0].name(db), + typevar_with_default.name(db), + )); + + if let [single_typevar] = invalid_later_typevars { + diagnostic.set_primary_message(format_args!( + "Type variable `{}` does not have a default", + single_typevar.name(db), )); + } else { + let later_typevars = + format_enumeration(invalid_later_typevars.iter().map(|tv| tv.name(db))); + diagnostic.set_primary_message(format_args!( + "Type variables {later_typevars} do not have defaults", + )); + } + + diagnostic.annotate( + Annotation::primary(Span::from(context.file()).with_range(primary_diagnostic_range)) + .message(format_args!( + "Earlier TypeVar `{}` does", + typevar_with_default.name(db) + )), + ); + + for tvar in [typevar_with_default, invalid_later_typevars[0]] { + let Some(definition) = tvar.definition(db) else { + continue; + }; + let file = definition.file(db); + diagnostic.annotate( + Annotation::secondary(Span::from( + definition.full_range(db, &parsed_module(db, file).load(db)), + )) + .message(format_args!("`{}` defined here", tvar.name(db))), + ); } } diff --git a/crates/ty_python_semantic/src/types/infer/builder.rs b/crates/ty_python_semantic/src/types/infer/builder.rs index b502f2f474..723e89519c 100644 --- a/crates/ty_python_semantic/src/types/infer/builder.rs +++ b/crates/ty_python_semantic/src/types/infer/builder.rs @@ -62,7 +62,7 @@ use crate::types::diagnostic::{ INVALID_BASE, INVALID_DECLARATION, INVALID_GENERIC_CLASS, INVALID_KEY, INVALID_LEGACY_TYPE_VARIABLE, INVALID_METACLASS, INVALID_NAMED_TUPLE, INVALID_NEWTYPE, INVALID_OVERLOAD, INVALID_PARAMETER_DEFAULT, INVALID_PARAMSPEC, INVALID_PROTOCOL, - INVALID_TYPE_ARGUMENTS, INVALID_TYPE_FORM, INVALID_TYPE_GUARD_CALL, INVALID_TYPE_PARAM_ORDER, + INVALID_TYPE_ARGUMENTS, INVALID_TYPE_FORM, INVALID_TYPE_GUARD_CALL, INVALID_TYPE_VARIABLE_CONSTRAINTS, IncompatibleBases, NON_SUBSCRIPTABLE, POSSIBLY_MISSING_ATTRIBUTE, POSSIBLY_MISSING_IMPLICIT_CALL, POSSIBLY_MISSING_IMPORT, SUBCLASS_OF_FINAL_CLASS, UNDEFINED_REVEAL, UNRESOLVED_ATTRIBUTE, UNRESOLVED_GLOBAL, @@ -949,44 +949,62 @@ impl<'db, 'ast> TypeInferenceBuilder<'db, 'ast> { } } - if self.context.is_lint_enabled(&INVALID_TYPE_PARAM_ORDER) { - if let Some(generic_context) = class.generic_context(self.db()) { - let mut seen_default = false; + if self.context.is_lint_enabled(&INVALID_GENERIC_CLASS) { + if !class.has_pep_695_type_params(self.db()) + && let Some(generic_context) = class.legacy_generic_context(self.db()) + { + struct State<'db> { + typevar_with_default: TypeVarInstance<'db>, + invalid_later_tvars: Vec>, + } + + let mut state: Option> = None; for bound_typevar in generic_context.variables(self.db()) { let typevar = bound_typevar.typevar(self.db()); let has_default = typevar.default_type(self.db()).is_some(); - if seen_default && !has_default { - report_invalid_type_param_order( - &self.context, - class, - typevar.name(self.db()).as_str(), - ); - } - if has_default { - seen_default = true; + if let Some(state) = state.as_mut() { + if !has_default { + state.invalid_later_tvars.push(typevar); + } + } else if has_default { + state = Some(State { + typevar_with_default: typevar, + invalid_later_tvars: vec![], + }); } } + + if let Some(state) = state + && !state.invalid_later_tvars.is_empty() + { + report_invalid_type_param_order( + &self.context, + class, + class_node, + state.typevar_with_default, + &state.invalid_later_tvars, + ); + } } - } - let scope = class.body_scope(self.db()).scope(self.db()); - if self.context.is_lint_enabled(&INVALID_GENERIC_CLASS) - && let Some(parent) = scope.parent() - { - for self_typevar in class.typevars_referenced_in_definition(self.db()) { - let self_typevar_name = self_typevar.typevar(self.db()).name(self.db()); - for enclosing in enclosing_generic_contexts(self.db(), self.index, parent) { - if let Some(other_typevar) = - enclosing.binds_named_typevar(self.db(), self_typevar_name) - { - report_rebound_typevar( - &self.context, - self_typevar_name, - class, - class_node, - other_typevar, - ); + + let scope = class.body_scope(self.db()).scope(self.db()); + if let Some(parent) = scope.parent() { + for self_typevar in class.typevars_referenced_in_definition(self.db()) { + let self_typevar_name = self_typevar.typevar(self.db()).name(self.db()); + for enclosing in enclosing_generic_contexts(self.db(), self.index, parent) { + if let Some(other_typevar) = + enclosing.binds_named_typevar(self.db(), self_typevar_name) + { + report_rebound_typevar( + &self.context, + self_typevar_name, + class, + class_node, + other_typevar, + ); + } } } }