Merge pull request #46 from pycompression/updatecli

Update CLI to reflect https://bugs.python.org/issue43316

Author: rhpvorderman

CHANGELOG.rst

@@ -9,6 +9,11 @@ Changelog
 
 version 0.6.0-dev
 -----------------
++ ``python -m gzip``'s behaviour has been changed since fixing bug:
+  `bpo-43316 <https://bugs.python.org/issue43316>`_. This bug was not present
+  in ``python -m isal.igzip`` but it handled the error differently than the
+  solution in CPython. This is now corrected and ``python -m isal.igzip``
+  handles the error the same as the fixed ``python -m gzip``.
 + Installation on Windows is now supported. Wheels are provided for Windows as
   well.
 

src/isal/igzip.py

@@ -295,7 +295,7 @@ def main():
     elif not args.compress and args.file is not None:
         base, extension = os.path.splitext(args.file)
         if extension != ".gz":
-            raise ValueError(f"filename doesn't end in .gz: {args.file}. ")
+            sys.exit(f"filename doesn't end in .gz: {args.file!r}")
         in_file = open(args.file, "rb")
 
     # Determine output file

tests/test_gzip_compliance.py

@@ -823,14 +823,9 @@ def test_decompress_infile_outfile(self):
     def test_decompress_infile_outfile_error(self):
         rc, out, err = assert_python_failure('-m', 'isal.igzip', '-d',
                                              'thisisatest.out')
-        # We take a divide from the original gzip module here. Error messages
-        # should be printed in stderr. Also exit code should not be 0!
-        # in python -m gzip -d mycompressedfile > decompressed
-        # will simply make decompressed contents 'filename doesn't end in .gz'
-        # without throwing an error. Crazy!
-        # TODO: Report a bug in CPython for gzip module
-        self.assertIn(b"filename doesn't end in .gz:", err)
-        self.assertNotEqual(rc, 0)
+        self.assertEqual(b"filename doesn't end in .gz: 'thisisatest.out'",
+                         err.strip())
+        self.assertEqual(rc, 1)
         self.assertEqual(out, b'')
 
     @create_and_remove_directory(TEMPDIR)

tests/test_igzip.py

@@ -92,7 +92,7 @@ def test_compress_infile_outfile(tmp_path, capsysbinary):
 
 def test_decompress_infile_outfile_error(capsysbinary):
     sys.argv = ['', '-d', 'thisisatest.out']
-    with pytest.raises(ValueError) as error:
+    with pytest.raises(SystemExit) as error:
         igzip.main()
     assert error.match("filename doesn't end")
     out, err = capsysbinary.readouterr()