1 files changed, 14 insertions, 0 deletions
diff --git a/Lib/test/test_capi/test_unicode.py b/Lib/test/test_capi/test_unicode.py
index c8be4f3faa9..6a9c60f3a6d 100644
--- a/Lib/test/test_capi/test_unicode.py
+++ b/Lib/test/test_capi/test_unicode.py
@@ -1739,6 +1739,20 @@ class CAPITest(unittest.TestCase):
                 # Check that the second call returns the same result
                 self.assertEqual(getargs_s_hash(s), chr(k).encode() * (i + 1))
 
+    @support.cpython_only
+    @unittest.skipIf(_testcapi is None, 'need _testcapi module')
+    def test_GET_CACHED_HASH(self):
+        from _testcapi import unicode_GET_CACHED_HASH
+        content_bytes = b'some new string'
+        # avoid parser interning & constant folding
+        obj = str(content_bytes, 'ascii')
+        # impl detail: fresh strings do not have cached hash
+        self.assertEqual(unicode_GET_CACHED_HASH(obj), -1)
+        # impl detail: adding string to a dict caches its hash
+        {obj: obj}
+        # impl detail: ASCII string hashes are equal to bytes ones
+        self.assertEqual(unicode_GET_CACHED_HASH(obj), hash(content_bytes))
+
 
 class PyUnicodeWriterTest(unittest.TestCase):
     def create_writer(self, size):