[syntax-errors] Type parameter defaults before Python 3.13 (#16447)

Summary
--

Detects the presence of a [PEP 696] type parameter default before Python
3.13.

Test Plan
--

New inline parser tests for type aliases, generic functions and generic
classes.

[PEP 696]: https://peps.python.org/pep-0696/#grammar-changes
This commit is contained in:
Brent Westbrook 2025-03-04 11:53:38 -05:00 committed by GitHub
parent c8a06a9be8
commit e7b93f93ef
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GPG key ID: B5690EEEBB952194
6 changed files with 514 additions and 4 deletions

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@ -0,0 +1,5 @@
# parse_options: {"target-version": "3.12"}
type X[T = int] = int
def f[T = int](): ...
class C[T = int](): ...
class D[S, T = int, U = uint](): ...

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@ -0,0 +1,4 @@
# parse_options: {"target-version": "3.13"}
type X[T = int] = int
def f[T = int](): ...
class C[T = int](): ...

View file

@ -449,18 +449,22 @@ pub enum UnsupportedSyntaxErrorKind {
Match,
Walrus,
ExceptStar,
TypeParamDefault,
}
impl Display for UnsupportedSyntaxError {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
let kind = match self.kind {
UnsupportedSyntaxErrorKind::Match => "`match` statement",
UnsupportedSyntaxErrorKind::Walrus => "named assignment expression (`:=`)",
UnsupportedSyntaxErrorKind::ExceptStar => "`except*`",
UnsupportedSyntaxErrorKind::Match => "Cannot use `match` statement",
UnsupportedSyntaxErrorKind::Walrus => "Cannot use named assignment expression (`:=`)",
UnsupportedSyntaxErrorKind::ExceptStar => "Cannot use `except*`",
UnsupportedSyntaxErrorKind::TypeParamDefault => {
"Cannot set default type for a type parameter"
}
};
write!(
f,
"Cannot use {kind} on Python {} (syntax was added in Python {})",
"{kind} on Python {} (syntax was added in Python {})",
self.target_version,
self.kind.minimum_version(),
)
@ -474,6 +478,7 @@ impl UnsupportedSyntaxErrorKind {
UnsupportedSyntaxErrorKind::Match => PythonVersion::PY310,
UnsupportedSyntaxErrorKind::Walrus => PythonVersion::PY38,
UnsupportedSyntaxErrorKind::ExceptStar => PythonVersion::PY311,
UnsupportedSyntaxErrorKind::TypeParamDefault => PythonVersion::PY313,
}
}
}

View file

@ -3243,6 +3243,7 @@ impl<'src> Parser<'src> {
None
};
let equal_token_start = self.node_start();
let default = if self.eat(TokenKind::Equal) {
if self.at_expr() {
// test_err type_param_type_var_invalid_default_expr
@ -3268,6 +3269,26 @@ impl<'src> Parser<'src> {
None
};
// test_ok type_param_default_py313
// # parse_options: {"target-version": "3.13"}
// type X[T = int] = int
// def f[T = int](): ...
// class C[T = int](): ...
// test_err type_param_default_py312
// # parse_options: {"target-version": "3.12"}
// type X[T = int] = int
// def f[T = int](): ...
// class C[T = int](): ...
// class D[S, T = int, U = uint](): ...
if default.is_some() {
self.add_unsupported_syntax_error(
UnsupportedSyntaxErrorKind::TypeParamDefault,
self.node_range(equal_token_start),
);
}
ast::TypeParam::TypeVar(ast::TypeParamTypeVar {
range: self.node_range(start),
name,

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@ -0,0 +1,302 @@
---
source: crates/ruff_python_parser/tests/fixtures.rs
input_file: crates/ruff_python_parser/resources/inline/err/type_param_default_py312.py
---
## AST
```
Module(
ModModule {
range: 0..149,
body: [
TypeAlias(
StmtTypeAlias {
range: 44..65,
name: Name(
ExprName {
range: 49..50,
id: Name("X"),
ctx: Store,
},
),
type_params: Some(
TypeParams {
range: 50..59,
type_params: [
TypeVar(
TypeParamTypeVar {
range: 51..58,
name: Identifier {
id: Name("T"),
range: 51..52,
},
bound: None,
default: Some(
Name(
ExprName {
range: 55..58,
id: Name("int"),
ctx: Load,
},
),
),
},
),
],
},
),
value: Name(
ExprName {
range: 62..65,
id: Name("int"),
ctx: Load,
},
),
},
),
FunctionDef(
StmtFunctionDef {
range: 66..87,
is_async: false,
decorator_list: [],
name: Identifier {
id: Name("f"),
range: 70..71,
},
type_params: Some(
TypeParams {
range: 71..80,
type_params: [
TypeVar(
TypeParamTypeVar {
range: 72..79,
name: Identifier {
id: Name("T"),
range: 72..73,
},
bound: None,
default: Some(
Name(
ExprName {
range: 76..79,
id: Name("int"),
ctx: Load,
},
),
),
},
),
],
},
),
parameters: Parameters {
range: 80..82,
posonlyargs: [],
args: [],
vararg: None,
kwonlyargs: [],
kwarg: None,
},
returns: None,
body: [
Expr(
StmtExpr {
range: 84..87,
value: EllipsisLiteral(
ExprEllipsisLiteral {
range: 84..87,
},
),
},
),
],
},
),
ClassDef(
StmtClassDef {
range: 88..111,
decorator_list: [],
name: Identifier {
id: Name("C"),
range: 94..95,
},
type_params: Some(
TypeParams {
range: 95..104,
type_params: [
TypeVar(
TypeParamTypeVar {
range: 96..103,
name: Identifier {
id: Name("T"),
range: 96..97,
},
bound: None,
default: Some(
Name(
ExprName {
range: 100..103,
id: Name("int"),
ctx: Load,
},
),
),
},
),
],
},
),
arguments: Some(
Arguments {
range: 104..106,
args: [],
keywords: [],
},
),
body: [
Expr(
StmtExpr {
range: 108..111,
value: EllipsisLiteral(
ExprEllipsisLiteral {
range: 108..111,
},
),
},
),
],
},
),
ClassDef(
StmtClassDef {
range: 112..148,
decorator_list: [],
name: Identifier {
id: Name("D"),
range: 118..119,
},
type_params: Some(
TypeParams {
range: 119..141,
type_params: [
TypeVar(
TypeParamTypeVar {
range: 120..121,
name: Identifier {
id: Name("S"),
range: 120..121,
},
bound: None,
default: None,
},
),
TypeVar(
TypeParamTypeVar {
range: 123..130,
name: Identifier {
id: Name("T"),
range: 123..124,
},
bound: None,
default: Some(
Name(
ExprName {
range: 127..130,
id: Name("int"),
ctx: Load,
},
),
),
},
),
TypeVar(
TypeParamTypeVar {
range: 132..140,
name: Identifier {
id: Name("U"),
range: 132..133,
},
bound: None,
default: Some(
Name(
ExprName {
range: 136..140,
id: Name("uint"),
ctx: Load,
},
),
),
},
),
],
},
),
arguments: Some(
Arguments {
range: 141..143,
args: [],
keywords: [],
},
),
body: [
Expr(
StmtExpr {
range: 145..148,
value: EllipsisLiteral(
ExprEllipsisLiteral {
range: 145..148,
},
),
},
),
],
},
),
],
},
)
```
## Unsupported Syntax Errors
|
1 | # parse_options: {"target-version": "3.12"}
2 | type X[T = int] = int
| ^^^^^ Syntax Error: Cannot set default type for a type parameter on Python 3.12 (syntax was added in Python 3.13)
3 | def f[T = int](): ...
4 | class C[T = int](): ...
|
|
1 | # parse_options: {"target-version": "3.12"}
2 | type X[T = int] = int
3 | def f[T = int](): ...
| ^^^^^ Syntax Error: Cannot set default type for a type parameter on Python 3.12 (syntax was added in Python 3.13)
4 | class C[T = int](): ...
5 | class D[S, T = int, U = uint](): ...
|
|
2 | type X[T = int] = int
3 | def f[T = int](): ...
4 | class C[T = int](): ...
| ^^^^^ Syntax Error: Cannot set default type for a type parameter on Python 3.12 (syntax was added in Python 3.13)
5 | class D[S, T = int, U = uint](): ...
|
|
3 | def f[T = int](): ...
4 | class C[T = int](): ...
5 | class D[S, T = int, U = uint](): ...
| ^^^^^ Syntax Error: Cannot set default type for a type parameter on Python 3.12 (syntax was added in Python 3.13)
|
|
3 | def f[T = int](): ...
4 | class C[T = int](): ...
5 | class D[S, T = int, U = uint](): ...
| ^^^^^^ Syntax Error: Cannot set default type for a type parameter on Python 3.12 (syntax was added in Python 3.13)
|

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@ -0,0 +1,173 @@
---
source: crates/ruff_python_parser/tests/fixtures.rs
input_file: crates/ruff_python_parser/resources/inline/ok/type_param_default_py313.py
---
## AST
```
Module(
ModModule {
range: 0..112,
body: [
TypeAlias(
StmtTypeAlias {
range: 44..65,
name: Name(
ExprName {
range: 49..50,
id: Name("X"),
ctx: Store,
},
),
type_params: Some(
TypeParams {
range: 50..59,
type_params: [
TypeVar(
TypeParamTypeVar {
range: 51..58,
name: Identifier {
id: Name("T"),
range: 51..52,
},
bound: None,
default: Some(
Name(
ExprName {
range: 55..58,
id: Name("int"),
ctx: Load,
},
),
),
},
),
],
},
),
value: Name(
ExprName {
range: 62..65,
id: Name("int"),
ctx: Load,
},
),
},
),
FunctionDef(
StmtFunctionDef {
range: 66..87,
is_async: false,
decorator_list: [],
name: Identifier {
id: Name("f"),
range: 70..71,
},
type_params: Some(
TypeParams {
range: 71..80,
type_params: [
TypeVar(
TypeParamTypeVar {
range: 72..79,
name: Identifier {
id: Name("T"),
range: 72..73,
},
bound: None,
default: Some(
Name(
ExprName {
range: 76..79,
id: Name("int"),
ctx: Load,
},
),
),
},
),
],
},
),
parameters: Parameters {
range: 80..82,
posonlyargs: [],
args: [],
vararg: None,
kwonlyargs: [],
kwarg: None,
},
returns: None,
body: [
Expr(
StmtExpr {
range: 84..87,
value: EllipsisLiteral(
ExprEllipsisLiteral {
range: 84..87,
},
),
},
),
],
},
),
ClassDef(
StmtClassDef {
range: 88..111,
decorator_list: [],
name: Identifier {
id: Name("C"),
range: 94..95,
},
type_params: Some(
TypeParams {
range: 95..104,
type_params: [
TypeVar(
TypeParamTypeVar {
range: 96..103,
name: Identifier {
id: Name("T"),
range: 96..97,
},
bound: None,
default: Some(
Name(
ExprName {
range: 100..103,
id: Name("int"),
ctx: Load,
},
),
),
},
),
],
},
),
arguments: Some(
Arguments {
range: 104..106,
args: [],
keywords: [],
},
),
body: [
Expr(
StmtExpr {
range: 108..111,
value: EllipsisLiteral(
ExprEllipsisLiteral {
range: 108..111,
},
),
},
),
],
},
),
],
},
)
```