Port test_datasets_utils to pytest (#4114)

test/common_utils.py

@@ -240,23 +240,6 @@ def disable_console_output():
         yield
 
 
-def call_args_to_kwargs_only(call_args, *callable_or_arg_names):
-    callable_or_arg_name = callable_or_arg_names[0]
-    if callable(callable_or_arg_name):
-        argspec = inspect.getfullargspec(callable_or_arg_name)
-        arg_names = argspec.args
-        if isinstance(callable_or_arg_name, type):
-            # remove self
-            arg_names.pop(0)
-    else:
-        arg_names = callable_or_arg_names
-
-    args, kwargs = call_args
-    kwargs_only = kwargs.copy()
-    kwargs_only.update(dict(zip(arg_names, args)))
-    return kwargs_only
-
-
 def cpu_and_gpu():
     import pytest  # noqa
     return ('cpu', pytest.param('cuda', marks=pytest.mark.needs_cuda))

test/test_datasets_utils.py

 import bz2
 import os
 import torchvision.datasets.utils as utils
-import unittest
-import unittest.mock
+import pytest
 import zipfile
 import tarfile
 import gzip
@@ -12,31 +11,32 @@ from urllib.error import URLError
 import itertools
 import lzma
 
-from common_utils import get_tmp_dir, call_args_to_kwargs_only
+from common_utils import get_tmp_dir
+from torchvision.datasets.utils import _COMPRESSED_FILE_OPENERS
 
 
 TEST_FILE = get_file_path_2(
     os.path.dirname(os.path.abspath(__file__)), 'assets', 'encode_jpeg', 'grace_hopper_517x606.jpg')
 
 
-class Tester(unittest.TestCase):
+class TestDatasetsUtils:
 
     def test_check_md5(self):
         fpath = TEST_FILE
         correct_md5 = '9c0bb82894bb3af7f7675ef2b3b6dcdc'
         false_md5 = ''
-        self.assertTrue(utils.check_md5(fpath, correct_md5))
-        self.assertFalse(utils.check_md5(fpath, false_md5))
+        assert utils.check_md5(fpath, correct_md5)
+        assert not utils.check_md5(fpath, false_md5)
 
     def test_check_integrity(self):
         existing_fpath = TEST_FILE
         nonexisting_fpath = ''
         correct_md5 = '9c0bb82894bb3af7f7675ef2b3b6dcdc'
         false_md5 = ''
-        self.assertTrue(utils.check_integrity(existing_fpath, correct_md5))
-        self.assertFalse(utils.check_integrity(existing_fpath, false_md5))
-        self.assertTrue(utils.check_integrity(existing_fpath))
-        self.assertFalse(utils.check_integrity(nonexisting_fpath))
+        assert utils.check_integrity(existing_fpath, correct_md5)
+        assert not utils.check_integrity(existing_fpath, false_md5)
+        assert utils.check_integrity(existing_fpath)
+        assert not utils.check_integrity(nonexisting_fpath)
 
     def test_get_google_drive_file_id(self):
         url = "https://drive.google.com/file/d/1hbzc_P1FuxMkcabkgn9ZKinBwW683j45/view"
@@ -50,8 +50,7 @@ class Tester(unittest.TestCase):
 
         assert utils._get_google_drive_file_id(url) is None
 
-    def test_detect_file_type(self):
-        for file, expected in [
+    @pytest.mark.parametrize('file, expected', [
         ("foo.tar.bz2", (".tar.bz2", ".tar", ".bz2")),
         ("foo.tar.xz", (".tar.xz", ".tar", ".xz")),
         ("foo.tar", (".tar", ".tar", None)),
@@ -65,29 +64,24 @@ class Tester(unittest.TestCase):
         ("foo.xz", (".xz", None, ".xz")),
         ("foo.bar.tar.gz", (".tar.gz", ".tar", ".gz")),
         ("foo.bar.gz", (".gz", None, ".gz")),
-            ("foo.bar.zip", (".zip", ".zip", None)),
-        ]:
-            with self.subTest(file=file):
-                self.assertSequenceEqual(utils._detect_file_type(file), expected)
-
-    def test_detect_file_type_no_ext(self):
-        with self.assertRaises(RuntimeError):
-            utils._detect_file_type("foo")
-
-    def test_detect_file_type_unknown_compression(self):
-        with self.assertRaises(RuntimeError):
-            utils._detect_file_type("foo.tar.baz")
-
-    def test_detect_file_type_unknown_partial_ext(self):
-        with self.assertRaises(RuntimeError):
-            utils._detect_file_type("foo.bar")
-
-    def test_decompress_bz2(self):
+        ("foo.bar.zip", (".zip", ".zip", None))])
+    def test_detect_file_type(self, file, expected):
+        assert utils._detect_file_type(file) == expected
+
+    @pytest.mark.parametrize('file', ["foo", "foo.tar.baz", "foo.bar"])
+    def test_detect_file_type_incompatible(self, file):
+        # tests detect file type for no extension, unknown compression and unknown partial extension
+        with pytest.raises(RuntimeError):
+            utils._detect_file_type(file)
+
+    @pytest.mark.parametrize('extension', [".bz2", ".gz", ".xz"])
+    def test_decompress(self, extension):
         def create_compressed(root, content="this is the content"):
             file = os.path.join(root, "file")
-            compressed = f"{file}.bz2"
+            compressed = f"{file}{extension}"
+            compressed_file_opener = _COMPRESSED_FILE_OPENERS[extension]
 
-            with bz2.open(compressed, "wb") as fh:
+            with compressed_file_opener(compressed, "wb") as fh:
                 fh.write(content.encode())
 
             return compressed, file, content
@@ -97,53 +91,13 @@ class Tester(unittest.TestCase):
 
             utils._decompress(compressed)
 
-            self.assertTrue(os.path.exists(file))
-
-            with open(file, "r") as fh:
-                self.assertEqual(fh.read(), content)
-
-    def test_decompress_gzip(self):
-        def create_compressed(root, content="this is the content"):
-            file = os.path.join(root, "file")
-            compressed = f"{file}.gz"
-
-            with gzip.open(compressed, "wb") as fh:
-                fh.write(content.encode())
-
-            return compressed, file, content
-
-        with get_tmp_dir() as temp_dir:
-            compressed, file, content = create_compressed(temp_dir)
-
-            utils._decompress(compressed)
-
-            self.assertTrue(os.path.exists(file))
-
-            with open(file, "r") as fh:
-                self.assertEqual(fh.read(), content)
-
-    def test_decompress_lzma(self):
-        def create_compressed(root, content="this is the content"):
-            file = os.path.join(root, "file")
-            compressed = f"{file}.xz"
-
-            with lzma.open(compressed, "wb") as fh:
-                fh.write(content.encode())
-
-            return compressed, file, content
-
-        with get_tmp_dir() as temp_dir:
-            compressed, file, content = create_compressed(temp_dir)
-
-            utils.extract_archive(compressed, temp_dir)
-
-            self.assertTrue(os.path.exists(file))
+            assert os.path.exists(file)
 
             with open(file, "r") as fh:
-                self.assertEqual(fh.read(), content)
+                assert fh.read() == content
 
     def test_decompress_no_compression(self):
-        with self.assertRaises(RuntimeError):
+        with pytest.raises(RuntimeError):
             utils._decompress("foo.tar")
 
     def test_decompress_remove_finished(self):
@@ -161,21 +115,18 @@ class Tester(unittest.TestCase):
 
             utils.extract_archive(compressed, temp_dir, remove_finished=True)
 
-            self.assertFalse(os.path.exists(compressed))
+            assert not os.path.exists(compressed)
 
-    def test_extract_archive_defer_to_decompress(self):
+    @pytest.mark.parametrize('extension', [".gz", ".xz"])
+    @pytest.mark.parametrize('remove_finished', [True, False])
+    def test_extract_archive_defer_to_decompress(self, extension, remove_finished, mocker):
         filename = "foo"
-        for ext, remove_finished in itertools.product((".gz", ".xz"), (True, False)):
-            with self.subTest(ext=ext, remove_finished=remove_finished):
-                with unittest.mock.patch("torchvision.datasets.utils._decompress") as mock:
-                    file = f"{filename}{ext}"
+        file = f"{filename}{extension}"
+
+        mocked = mocker.patch("torchvision.datasets.utils._decompress")
         utils.extract_archive(file, remove_finished=remove_finished)
 
-                mock.assert_called_once()
-                self.assertEqual(
-                    call_args_to_kwargs_only(mock.call_args, utils._decompress),
-                    dict(from_path=file, to_path=filename, remove_finished=remove_finished),
-                )
+        mocked.assert_called_once_with(file, filename, remove_finished=remove_finished)
 
     def test_extract_zip(self):
         def create_archive(root, content="this is the content"):
@@ -192,41 +143,18 @@ class Tester(unittest.TestCase):
 
             utils.extract_archive(archive, temp_dir)
 
-            self.assertTrue(os.path.exists(file))
-
-            with open(file, "r") as fh:
-                self.assertEqual(fh.read(), content)
-
-    def test_extract_tar(self):
-        def create_archive(root, ext, mode, content="this is the content"):
-            src = os.path.join(root, "src.txt")
-            dst = os.path.join(root, "dst.txt")
-            archive = os.path.join(root, f"archive{ext}")
-
-            with open(src, "w") as fh:
-                fh.write(content)
-
-            with tarfile.open(archive, mode=mode) as fh:
-                fh.add(src, arcname=os.path.basename(dst))
-
-            return archive, dst, content
-
-        for ext, mode in zip(['.tar', '.tar.gz', '.tgz'], ['w', 'w:gz', 'w:gz']):
-            with get_tmp_dir() as temp_dir:
-                archive, file, content = create_archive(temp_dir, ext, mode)
-
-                utils.extract_archive(archive, temp_dir)
-
-                self.assertTrue(os.path.exists(file))
+            assert os.path.exists(file)
 
             with open(file, "r") as fh:
-                    self.assertEqual(fh.read(), content)
+                assert fh.read() == content
 
-    def test_extract_tar_xz(self):
-        def create_archive(root, ext, mode, content="this is the content"):
+    @pytest.mark.parametrize('extension, mode', [
+        ('.tar', 'w'), ('.tar.gz', 'w:gz'), ('.tgz', 'w:gz'), ('.tar.xz', 'w:xz')])
+    def test_extract_tar(self, extension, mode):
+        def create_archive(root, extension, mode, content="this is the content"):
             src = os.path.join(root, "src.txt")
             dst = os.path.join(root, "dst.txt")
-            archive = os.path.join(root, f"archive{ext}")
+            archive = os.path.join(root, f"archive{extension}")
 
             with open(src, "w") as fh:
                 fh.write(content)
@@ -236,22 +164,21 @@ class Tester(unittest.TestCase):
 
             return archive, dst, content
 
-        for ext, mode in zip(['.tar.xz'], ['w:xz']):
         with get_tmp_dir() as temp_dir:
-                archive, file, content = create_archive(temp_dir, ext, mode)
+            archive, file, content = create_archive(temp_dir, extension, mode)
 
             utils.extract_archive(archive, temp_dir)
 
-                self.assertTrue(os.path.exists(file))
+            assert os.path.exists(file)
 
             with open(file, "r") as fh:
-                    self.assertEqual(fh.read(), content)
+                assert fh.read() == content
 
     def test_verify_str_arg(self):
-        self.assertEqual("a", utils.verify_str_arg("a", "arg", ("a",)))
-        self.assertRaises(ValueError, utils.verify_str_arg, 0, ("a",), "arg")
-        self.assertRaises(ValueError, utils.verify_str_arg, "b", ("a",), "arg")
+        assert "a" == utils.verify_str_arg("a", "arg", ("a",))
+        pytest.raises(ValueError, utils.verify_str_arg, 0, ("a",), "arg")
+        pytest.raises(ValueError, utils.verify_str_arg, "b", ("a",), "arg")
 
 
 if __name__ == '__main__':
-    unittest.main()
+    pytest.main([__file__])