sfnt_test: add test for deepcopy and pickle

Tests/ttLib/sfnt_test.py

@@ -1,7 +1,59 @@
-from fontTools.misc.py23 import *
-from fontTools.ttLib.sfnt import calcChecksum
+import io
+import copy
+import pickle
+from fontTools.ttLib.sfnt import calcChecksum, SFNTReader
+import pytest
 
 
 def test_calcChecksum():
     assert calcChecksum(b"abcd") == 1633837924
     assert calcChecksum(b"abcdxyz") == 3655064932
+
+
+EMPTY_SFNT = b"\x00\x01\x00\x00" + b"\x00" * 8
+
+
+def pickle_unpickle(obj):
+    return pickle.loads(pickle.dumps(obj))
+
+
+class SFNTReaderTest:
+    @pytest.mark.parametrize("deepcopy", [copy.deepcopy, pickle_unpickle])
+    def test_pickle_protocol_FileIO(self, deepcopy, tmp_path):
+        fontfile = tmp_path / "test.ttf"
+        fontfile.write_bytes(EMPTY_SFNT)
+        reader = SFNTReader(fontfile.open("rb"))
+
+        reader2 = deepcopy(reader)
+
+        assert reader2 is not reader
+        assert reader2.file is not reader.file
+
+        assert isinstance(reader2.file, io.BufferedReader)
+        assert isinstance(reader2.file.raw, io.FileIO)
+        assert reader2.file.name == reader.file.name
+        assert reader2.file.tell() == reader.file.tell()
+
+        for k, v in reader.__dict__.items():
+            if k == "file":
+                continue
+            assert getattr(reader2, k) == v
+
+    @pytest.mark.parametrize("deepcopy", [copy.deepcopy, pickle_unpickle])
+    def test_pickle_protocol_BytesIO(self, deepcopy, tmp_path):
+        buf = io.BytesIO(EMPTY_SFNT)
+        reader = SFNTReader(buf)
+
+        reader2 = deepcopy(reader)
+
+        assert reader2 is not reader
+        assert reader2.file is not reader.file
+
+        assert isinstance(reader2.file, io.BytesIO)
+        assert reader2.file.tell() == reader.file.tell()
+        assert reader2.file.getvalue() == reader.file.getvalue()
+
+        for k, v in reader.__dict__.items():
+            if k == "file":
+                continue
+            assert getattr(reader2, k) == v