Closes #13989: Add support for text modes to gzip.open().

Also, add tests for gzip.open().

1 files changed, 88 insertions, 0 deletions

diff --git a/Lib/test/test_gzip.py b/Lib/test/test_gzip.py
index d2b4871..db1312d 100644
--- a/Lib/test/test_gzip.py
+++ b/Lib/test/test_gzip.py
@@ -374,6 +374,94 @@ class TestGzip(unittest.TestCase):
             datac = gzip.compress(data)
             self.assertEqual(gzip.decompress(datac), data)
 
+    # Test the 'open' convenience function.
+
+    def test_open_binary(self):
+        # Test explicit binary modes.
+        uncompressed = data1 * 50
+        with gzip.open(self.filename, "wb") as f:
+            f.write(uncompressed)
+        with open(self.filename, "rb") as f:
+            file_data = gzip.decompress(f.read())
+            self.assertEqual(file_data, uncompressed)
+        with gzip.open(self.filename, "rb") as f:
+            self.assertEqual(f.read(), uncompressed)
+        with gzip.open(self.filename, "ab") as f:
+            f.write(uncompressed)
+        with open(self.filename, "rb") as f:
+            file_data = gzip.decompress(f.read())
+            self.assertEqual(file_data, uncompressed * 2)
+
+    def test_open_default_binary(self):
+        # Test implicit binary modes (no "b" or "t" in mode string).
+        uncompressed = data1 * 50
+        with gzip.open(self.filename, "w") as f:
+            f.write(uncompressed)
+        with open(self.filename, "rb") as f:
+            file_data = gzip.decompress(f.read())
+            self.assertEqual(file_data, uncompressed)
+        with gzip.open(self.filename, "r") as f:
+            self.assertEqual(f.read(), uncompressed)
+        with gzip.open(self.filename, "a") as f:
+            f.write(uncompressed)
+        with open(self.filename, "rb") as f:
+            file_data = gzip.decompress(f.read())
+            self.assertEqual(file_data, uncompressed * 2)
+
+    def test_open_text(self):
+        # Test text modes.
+        uncompressed = data1.decode("ascii") * 50
+        with gzip.open(self.filename, "wt") as f:
+            f.write(uncompressed)
+        with open(self.filename, "rb") as f:
+            file_data = gzip.decompress(f.read()).decode("ascii")
+            self.assertEqual(file_data, uncompressed)
+        with gzip.open(self.filename, "rt") as f:
+            self.assertEqual(f.read(), uncompressed)
+        with gzip.open(self.filename, "at") as f:
+            f.write(uncompressed)
+        with open(self.filename, "rb") as f:
+            file_data = gzip.decompress(f.read()).decode("ascii")
+            self.assertEqual(file_data, uncompressed * 2)
+
+    def test_open_bad_params(self):
+        # Test invalid parameter combinations.
+        with self.assertRaises(ValueError):
+            gzip.open(self.filename, "wbt")
+        with self.assertRaises(ValueError):
+            gzip.open(self.filename, "rb", encoding="utf-8")
+        with self.assertRaises(ValueError):
+            gzip.open(self.filename, "rb", errors="ignore")
+        with self.assertRaises(ValueError):
+            gzip.open(self.filename, "rb", newline="\n")
+
+    def test_open_with_encoding(self):
+        # Test non-default encoding.
+        uncompressed = data1.decode("ascii") * 50
+        with gzip.open(self.filename, "wt", encoding="utf-16") as f:
+            f.write(uncompressed)
+        with open(self.filename, "rb") as f:
+            file_data = gzip.decompress(f.read()).decode("utf-16")
+            self.assertEqual(file_data, uncompressed)
+        with gzip.open(self.filename, "rt", encoding="utf-16") as f:
+            self.assertEqual(f.read(), uncompressed)
+
+    def test_open_with_encoding_error_handler(self):
+        # Test with non-default encoding error handler.
+        with gzip.open(self.filename, "wb") as f:
+            f.write(b"foo\xffbar")
+        with gzip.open(self.filename, "rt", encoding="ascii", errors="ignore") \
+                as f:
+            self.assertEqual(f.read(), "foobar")
+
+    def test_open_with_newline(self):
+        # Test with explicit newline (universal newline mode disabled).
+        uncompressed = data1.decode("ascii") * 50
+        with gzip.open(self.filename, "wt") as f:
+            f.write(uncompressed)
+        with gzip.open(self.filename, "rt", newline="\r") as f:
+            self.assertEqual(f.readlines(), [uncompressed])
+
 def test_main(verbose=None):
     support.run_unittest(TestGzip)