add singledispatchmethod test for objects with equal hash and ==

eendebakpt · eendebakpt · commit 6c6e8b8d68d5 · 2024-12-11T19:30:16.000+01:00
diff --git a/Lib/test/test_functools.py b/Lib/test/test_functools.py
@@ -3228,6 +3228,25 @@ def f(arg):
             def _(arg: undefined):
                 return "forward reference"
 
+    def test_singledispatchmethod_hash_comparision_equal(self):
+        from dataclasses import dataclass
+
+        @dataclass(frozen=True)
+        class A:
+            value: int
+
+            @functools.singledispatchmethod
+            def dispatch(self, x):
+                return id(self)
+
+        t1 = A(1)
+        t2 = A(1)
+
+        assert t1 == t2
+        assert id(t1) == t1.dispatch(2)
+        assert id(t2) == t2.dispatch(2) # gh-127750
+
+
 class CachedCostItem:
     _cost = 1
 
