Check for deprecated typing.Set in check_new_syntax.py (#6365)

tests/check_new_syntax.py

@@ -18,6 +18,9 @@ def check_new_syntax(tree: ast.AST, path: Path) -> list[str]:
         return isinstance(node, ast.Constant) and node.s is Ellipsis
 
     class OldSyntaxFinder(ast.NodeVisitor):
+        def __init__(self, *, set_from_collections_abc: bool) -> None:
+            self.set_from_collections_abc = set_from_collections_abc
+
         def visit_Subscript(self, node: ast.Subscript) -> None:
             if isinstance(node.value, ast.Name):
                 if node.value.id == "Union" and isinstance(node.slice, ast.Tuple):
@@ -29,6 +32,9 @@ def check_new_syntax(tree: ast.AST, path: Path) -> list[str]:
                 if node.value.id in {"List", "FrozenSet"}:
                     new_syntax = f"{node.value.id.lower()}[{ast.unparse(node.slice)}]"
                     errors.append(f"{path}:{node.lineno}: Use built-in generics, e.g. `{new_syntax}`")
+                if not self.set_from_collections_abc and node.value.id == "Set":
+                    new_syntax = f"set[{ast.unparse(node.slice)}]"
+                    errors.append(f"{path}:{node.lineno}: Use built-in generics, e.g. `{new_syntax}`")
                 if node.value.id == "Deque":
                     new_syntax = f"collections.deque[{ast.unparse(node.slice)}]"
                     errors.append(f"{path}:{node.lineno}: Use `collections.deque` instead of `typing.Deque`, e.g. `{new_syntax}`")
@@ -55,21 +61,32 @@ def check_new_syntax(tree: ast.AST, path: Path) -> list[str]:
     #
     # TODO: can use built-in generics in type aliases
     class AnnotationFinder(ast.NodeVisitor):
+        def __init__(self) -> None:
+            self.set_from_collections_abc = False
+
+        def visit_ImportFrom(self, node: ast.ImportFrom) -> None:
+            if node.module == "collections.abc":
+                imported_classes = node.names
+                if any(cls.name == "Set" for cls in imported_classes):
+                    self.set_from_collections_abc = True
+
+            self.generic_visit(node)
+
         def visit_AnnAssign(self, node: ast.AnnAssign) -> None:
-            OldSyntaxFinder().visit(node.annotation)
+            OldSyntaxFinder(set_from_collections_abc=self.set_from_collections_abc).visit(node.annotation)
 
         def visit_arg(self, node: ast.arg) -> None:
             if node.annotation is not None:
-                OldSyntaxFinder().visit(node.annotation)
+                OldSyntaxFinder(set_from_collections_abc=self.set_from_collections_abc).visit(node.annotation)
 
         def visit_FunctionDef(self, node: ast.FunctionDef) -> None:
             if node.returns is not None:
-                OldSyntaxFinder().visit(node.returns)
+                OldSyntaxFinder(set_from_collections_abc=self.set_from_collections_abc).visit(node.returns)
             self.generic_visit(node)
 
         def visit_AsyncFunctionDef(self, node: ast.AsyncFunctionDef) -> None:
             if node.returns is not None:
-                OldSyntaxFinder().visit(node.returns)
+                OldSyntaxFinder(set_from_collections_abc=self.set_from_collections_abc).visit(node.returns)
             self.generic_visit(node)
 
     AnnotationFinder().visit(tree)