chore: import upstream snapshot with attribution

decoding/IAD/fairseq/tests/test_file_io.py

@@ -0,0 +1,47 @@
+# This source code is licensed under the MIT license found in the
+# LICENSE file in the root directory of this source tree.
+
+import os
+import shutil
+import sys
+import tempfile
+import unittest
+from typing import Optional
+from unittest.mock import MagicMock
+
+
+class TestFileIO(unittest.TestCase):
+
+    _tmpdir: Optional[str] = None
+    _tmpfile: Optional[str] = None
+    _tmpfile_contents = "Hello, World"
+
+    @classmethod
+    def setUpClass(cls) -> None:
+        cls._tmpdir = tempfile.mkdtemp()
+        with open(os.path.join(cls._tmpdir, "test.txt"), "w") as f:
+            cls._tmpfile = f.name
+            f.write(cls._tmpfile_contents)
+            f.flush()
+
+    @classmethod
+    def tearDownClass(cls) -> None:
+        # Cleanup temp working dir.
+        if cls._tmpdir is not None:
+            shutil.rmtree(cls._tmpdir)  # type: ignore
+
+    def test_file_io(self):
+        from fairseq.file_io import PathManager
+
+        with PathManager.open(os.path.join(self._tmpdir, "test.txt"), "r") as f:
+            s = f.read()
+        self.assertEqual(s, self._tmpfile_contents)
+
+    def test_file_io_oss(self):
+        # Mock fvcore to simulate oss environment.
+        sys.modules["fvcore"] = MagicMock()
+        from fairseq.file_io import PathManager
+
+        with PathManager.open(os.path.join(self._tmpdir, "test.txt"), "r") as f:
+            s = f.read()
+        self.assertEqual(s, self._tmpfile_contents)