pythongh-105164: Detect annotations inside match blocks

JelleZijlstra · Jun 1, 2023 · f7ed5ce · f7ed5ce
1 parent df396b5
commit f7ed5ce
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diff --git a/Lib/test/test_type_annotations.py b/Lib/test/test_type_annotations.py
@@ -1,4 +1,5 @@
 import unittest
+from test.support import run_code
 
 class TypeAnnotationTests(unittest.TestCase):
 
@@ -101,3 +102,17 @@ class D(metaclass=C):
         with self.assertRaises(AttributeError):
             del D.__annotations__
         self.assertEqual(D.__annotations__, {})
+
+    def test_module_level(self):
+        ns = run_code("x: int = 1")
+        self.assertEqual(ns["__annotations__"], {"x": int})
+
+        ns = run_code("if True:\n    x: int = 1")
+        self.assertEqual(ns["__annotations__"], {"x": int})
+
+        ns = run_code("""
+            match 0:
+                case 0:
+                    x: int = 1
+        """)
+        self.assertEqual(ns["__annotations__"], {"x": int})
diff --git a/Misc/NEWS.d/next/Core and Builtins/2023-05-31-19-35-22.gh-issue-105164.6Wajph.rst b/Misc/NEWS.d/next/Core and Builtins/2023-05-31-19-35-22.gh-issue-105164.6Wajph.rst
@@ -0,0 +1,2 @@
+Ensure annotations are set up correctly if the only annotation in a block is
+within a :keyword:`match` block. Patch by Jelle Zijlstra.
diff --git a/Python/compile.c b/Python/compile.c
@@ -1422,8 +1422,18 @@ find_ann(asdl_stmt_seq *stmts)
                   find_ann(st->v.TryStar.finalbody) ||
                   find_ann(st->v.TryStar.orelse);
             break;
+        case Match_kind:
+            for (j = 0; j < asdl_seq_LEN(st->v.Match.cases); j++) {
+                match_case_ty match_case = (match_case_ty)asdl_seq_GET(
+                    st->v.Match.cases, j);
+                if (find_ann(match_case->body)) {
+                    return true;
+                }
+            }
+            break;
         default:
             res = false;
+            break;
         }
         if (res) {
             break;