fix test

Author: Philip Meier

test/test_datasets.py

@@ -108,14 +108,14 @@ def test_fashionmnist(self, mock_download_extract):
             img, target = dataset[0]
             self.assertEqual(dataset.class_to_idx[dataset.classes[0]], target)
 
-    @mock.patch('torchvision.datasets.utils.download_url')
+    @mock.patch('torchvision.datasets.imagenet.ImageNet._verify_archive')
     @unittest.skipIf(not HAS_SCIPY, "scipy unavailable")
-    def test_imagenet(self, mock_download):
+    def test_imagenet(self, mock_check):
         with imagenet_root() as root:
-            dataset = torchvision.datasets.ImageNet(root, split='train', download=True)
+            dataset = torchvision.datasets.ImageNet(root, split='train')
             self.generic_classification_dataset_test(dataset)
 
-            dataset = torchvision.datasets.ImageNet(root, split='val', download=True)
+            dataset = torchvision.datasets.ImageNet(root, split='val')
             self.generic_classification_dataset_test(dataset)
 
     @mock.patch('torchvision.datasets.cifar.check_integrity')

torchvision/datasets/imagenet.py

@@ -73,29 +73,29 @@ def __init__(self, root, split='train', download=None, **kwargs):
                              for cls in clss}
 
     def extract_archives(self):
-        def check_archive(archive_dict):
-            file = archive_dict["file"]
-            md5 = archive_dict["md5"]
-            archive = os.path.join(self.root, file)
-            if not check_integrity(archive, md5):
-                msg = ("The file {} is not present in the root directory. You need to "
-                       "download it externally and place it in {}.")
-                raise RuntimeError(msg.format(file, self.root))
-
-            return archive
-
         if not check_integrity(self.meta_file):
-            archive = check_archive(ARCHIVE_DICT['devkit'])
+            archive_dict = ARCHIVE_DICT['devkit']
+            archive = os.path.join(self.root, archive_dict["file"])
+            self._verify_archive(archive, archive_dict["md5"])
+
             parse_devkit_archive(archive)
 
         if not os.path.isdir(self.split_folder):
-            archive = check_archive(ARCHIVE_DICT[self.split])
+            archive_dict = ARCHIVE_DICT[self.split]
+            archive = os.path.join(self.root, archive_dict["file"])
+            self._verify_archive(archive, archive_dict["md5"])
 
             if self.split == 'train':
                 parse_train_archive(archive)
             elif self.split == 'val':
                 parse_val_archive(archive)
 
+    def _verify_archive(self, archive, md5):
+        if not check_integrity(archive, md5):
+            msg = ("The file {} is not present in the root directory or corrupted. "
+                   "You need to download it externally and place it in {}.")
+            raise RuntimeError(msg.format(os.path.basename(archive), self.root))
+
     @property
     def meta_file(self):
         return os.path.join(self.root, META_FILE_NAME)