Issue #22113: struct.pack_into() now supports new buffer protocol (in

particular accepts writable memoryview).

1 files changed, 14 insertions, 5 deletions

diff --git a/Lib/test/test_struct.py b/Lib/test/test_struct.py
index 4811974..fe56dcb 100644
--- a/Lib/test/test_struct.py
+++ b/Lib/test/test_struct.py
@@ -433,24 +433,24 @@ class StructTest(unittest.TestCase):
             self.assertRaises(struct.error, s.unpack_from, data, i)
             self.assertRaises(struct.error, struct.unpack_from, fmt, data, i)
 
-    def test_pack_into(self):
+    def test_pack_into(self, cls=bytearray, tobytes=str):
         test_string = 'Reykjavik rocks, eow!'
-        writable_buf = array.array('c', ' '*100)
+        writable_buf = cls(' '*100)
         fmt = '21s'
         s = struct.Struct(fmt)
 
         # Test without offset
         s.pack_into(writable_buf, 0, test_string)
-        from_buf = writable_buf.tostring()[:len(test_string)]
+        from_buf = tobytes(writable_buf)[:len(test_string)]
         self.assertEqual(from_buf, test_string)
 
         # Test with offset.
         s.pack_into(writable_buf, 10, test_string)
-        from_buf = writable_buf.tostring()[:len(test_string)+10]
+        from_buf = tobytes(writable_buf)[:len(test_string)+10]
         self.assertEqual(from_buf, test_string[:10] + test_string)
 
         # Go beyond boundaries.
-        small_buf = array.array('c', ' '*10)
+        small_buf = cls(' '*10)
         self.assertRaises((ValueError, struct.error), s.pack_into, small_buf, 0,
                           test_string)
         self.assertRaises((ValueError, struct.error), s.pack_into, small_buf, 2,
@@ -461,6 +461,15 @@ class StructTest(unittest.TestCase):
         self.assertRaises((TypeError, struct.error), struct.pack_into, b'', sb,
                           None)
 
+    def test_pack_into_array(self):
+        self.test_pack_into(cls=lambda b: array.array('c', b),
+                            tobytes=array.array.tostring)
+
+    def test_pack_into_memoryview(self):
+        # Issue #22113
+        self.test_pack_into(cls=lambda b: memoryview(bytearray(b)),
+                            tobytes=memoryview.tobytes)
+
     def test_pack_into_fn(self):
         test_string = 'Reykjavik rocks, eow!'
         writable_buf = array.array('c', ' '*100)