Merge branch 'main' into literal-type

README.md

@@ -417,6 +417,7 @@ Ruff is used by a number of major open-source projects and companies, including:
 - [Babel](https://github.com/python-babel/babel)
 - Benchling ([Refac](https://github.com/benchling/refac))
 - [Bokeh](https://github.com/bokeh/bokeh)
+- CrowdCent ([NumerBlox](https://github.com/crowdcent/numerblox)) <!-- typos: ignore -->
 - [Cryptography (PyCA)](https://github.com/pyca/cryptography)
 - CERN ([Indico](https://getindico.io/))
 - [DVC](https://github.com/iterative/dvc)

_typos.toml

@@ -12,6 +12,7 @@ pn = "pn"  # `import panel as pn` is a thing
 poit = "poit"
 BA = "BA" # acronym for "Bad Allowed", used in testing.
 jod = "jod" # e.g., `jod-thread`
+Numer = "Numer" # Library name 'NumerBlox' in "Who's Using Ruff?"
 
 [default]
 extend-ignore-re = [

crates/red_knot_python_semantic/resources/mdtest/assignment/annotations.md

@@ -23,12 +23,21 @@ x: int
 x = "foo"  # error: [invalid-assignment] "Object of type `Literal["foo"]` is not assignable to `int`"
 ```
 
-## PEP-604 annotations not yet supported
+## PEP-604 annotations are supported
 
 ```py
-def f() -> str | None:
+def foo() -> str | int | None:
     return None
 
-# TODO: should be `str | None` (but Todo is better than `Unknown`)
-reveal_type(f())  # revealed: @Todo
+reveal_type(foo())  # revealed: str | int | None
+
+def bar() -> str | str | None:
+    return None
+
+reveal_type(bar())  # revealed: str | None
+
+def baz() -> str | str:
+    return "Hello, world!"
+
+reveal_type(baz())  # revealed: str
 ```

crates/red_knot_python_semantic/src/types/infer.rs

@@ -3584,14 +3584,20 @@ impl<'db> TypeInferenceBuilder<'db> {
 
             ast::Expr::Subscript(subscript) => self.infer_subscript_type_expression(subscript),
 
-            // TODO PEP-604 unions
             ast::Expr::BinOp(binary) => {
-                self.infer_binary_expression(binary);
+                #[allow(clippy::single_match_else)]
                 match binary.op {
-                    // PEP-604 unions are okay
-                    ast::Operator::BitOr => Type::Todo,
+                    // PEP-604 unions are okay, e.g., `int | str`
+                    ast::Operator::BitOr => {
+                        let left_ty = self.infer_type_expression(&binary.left);
+                        let right_ty = self.infer_type_expression(&binary.right);
+                        UnionType::from_elements(self.db, [left_ty, right_ty])
+                    }
                     // anything else is an invalid annotation:
-                    _ => Type::Unknown,
+                    _ => {
+                        self.infer_binary_expression(binary);
+                        Type::Unknown
+                    }
                 }
             }