Fix cached_file in offline mode for cached non-existing files (#19206)

* Fix cached_file in offline mode for cached non-existing files

* Add tests

* Test with offline mode

src/transformers/utils/hub.py

@@ -435,7 +435,7 @@ def cached_file(
     except LocalEntryNotFoundError:
         # We try to see if we have a cached version (not up to date):
         resolved_file = try_to_load_from_cache(path_or_repo_id, full_filename, cache_dir=cache_dir, revision=revision)
-        if resolved_file is not None:
+        if resolved_file is not None and resolved_file != _CACHED_NO_EXIST:
             return resolved_file
         if not _raise_exceptions_for_missing_entries or not _raise_exceptions_for_connection_errors:
             return None
@@ -457,7 +457,7 @@ def cached_file(
     except HTTPError as err:
         # First we try to see if we have a cached version (not up to date):
         resolved_file = try_to_load_from_cache(path_or_repo_id, full_filename, cache_dir=cache_dir, revision=revision)
-        if resolved_file is not None:
+        if resolved_file is not None and resolved_file != _CACHED_NO_EXIST:
             return resolved_file
         if not _raise_exceptions_for_connection_errors:
             return None

tests/utils/test_file_utils.py

@@ -15,28 +15,14 @@
 import contextlib
 import importlib
 import io
-import json
-import tempfile
 import unittest
-from pathlib import Path
 
 import transformers
 
 # Try to import everything from transformers to ensure every object can be loaded.
 from transformers import *  # noqa F406
 from transformers.testing_utils import DUMMY_UNKNOWN_IDENTIFIER
-from transformers.utils import (
+from transformers.utils import ContextManagers, find_labels, is_flax_available, is_tf_available, is_torch_available
-    FLAX_WEIGHTS_NAME,
-    TF2_WEIGHTS_NAME,
-    WEIGHTS_NAME,
-    ContextManagers,
-    find_labels,
-    get_file_from_repo,
-    has_file,
-    is_flax_available,
-    is_tf_available,
-    is_torch_available,
-)
 
 
 MODEL_ID = DUMMY_UNKNOWN_IDENTIFIER
@@ -77,38 +63,6 @@ class TestImportMechanisms(unittest.TestCase):
         assert importlib.util.find_spec("transformers") is not None
 
 
-class GetFromCacheTests(unittest.TestCase):
-    def test_has_file(self):
-        self.assertTrue(has_file("hf-internal-testing/tiny-bert-pt-only", WEIGHTS_NAME))
-        self.assertFalse(has_file("hf-internal-testing/tiny-bert-pt-only", TF2_WEIGHTS_NAME))
-        self.assertFalse(has_file("hf-internal-testing/tiny-bert-pt-only", FLAX_WEIGHTS_NAME))
-
-    def test_get_file_from_repo_distant(self):
-        # `get_file_from_repo` returns None if the file does not exist
-        self.assertIsNone(get_file_from_repo("bert-base-cased", "ahah.txt"))
-
-        # The function raises if the repository does not exist.
-        with self.assertRaisesRegex(EnvironmentError, "is not a valid model identifier"):
-            get_file_from_repo("bert-base-case", "config.json")
-
-        # The function raises if the revision does not exist.
-        with self.assertRaisesRegex(EnvironmentError, "is not a valid git identifier"):
-            get_file_from_repo("bert-base-cased", "config.json", revision="ahaha")
-
-        resolved_file = get_file_from_repo("bert-base-cased", "config.json")
-        # The name is the cached name which is not very easy to test, so instead we load the content.
-        config = json.loads(open(resolved_file, "r").read())
-        self.assertEqual(config["hidden_size"], 768)
-
-    def test_get_file_from_repo_local(self):
-        with tempfile.TemporaryDirectory() as tmp_dir:
-            filename = Path(tmp_dir) / "a.txt"
-            filename.touch()
-            self.assertEqual(get_file_from_repo(tmp_dir, "a.txt"), str(filename))
-
-            self.assertIsNone(get_file_from_repo(tmp_dir, "b.txt"))
-
-
 class GenericUtilTests(unittest.TestCase):
     @unittest.mock.patch("sys.stdout", new_callable=io.StringIO)
     def test_context_managers_no_context(self, mock_stdout):

tests/utils/test_hub_utils.py

@@ -0,0 +1,110 @@
+# Copyright 2020 The HuggingFace Team. All rights reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+import json
+import os
+import tempfile
+import unittest
+from pathlib import Path
+
+from transformers.utils import (
+    CONFIG_NAME,
+    FLAX_WEIGHTS_NAME,
+    TF2_WEIGHTS_NAME,
+    TRANSFORMERS_CACHE,
+    WEIGHTS_NAME,
+    cached_file,
+    get_file_from_repo,
+    has_file,
+)
+
+
+RANDOM_BERT = "hf-internal-testing/tiny-random-bert"
+CACHE_DIR = os.path.join(TRANSFORMERS_CACHE, "models--hf-internal-testing--tiny-random-bert")
+FULL_COMMIT_HASH = "9b8c223d42b2188cb49d29af482996f9d0f3e5a6"
+
+
+class GetFromCacheTests(unittest.TestCase):
+    def test_cached_file(self):
+        archive_file = cached_file(RANDOM_BERT, CONFIG_NAME)
+        # Should have downloaded the file in here
+        self.assertTrue(os.path.isdir(CACHE_DIR))
+        # Cache should contain at least those three subfolders:
+        for subfolder in ["blobs", "refs", "snapshots"]:
+            self.assertTrue(os.path.isdir(os.path.join(CACHE_DIR, subfolder)))
+        with open(os.path.join(CACHE_DIR, "refs", "main")) as f:
+            main_commit = f.read()
+        self.assertEqual(archive_file, os.path.join(CACHE_DIR, "snapshots", main_commit, CONFIG_NAME))
+        self.assertTrue(os.path.isfile(archive_file))
+
+        # File is cached at the same place the second time.
+        new_archive_file = cached_file(RANDOM_BERT, CONFIG_NAME)
+        self.assertEqual(archive_file, new_archive_file)
+
+        # Using a specific revision to test the full commit hash.
+        archive_file = cached_file(RANDOM_BERT, CONFIG_NAME, revision="9b8c223")
+        self.assertEqual(archive_file, os.path.join(CACHE_DIR, "snapshots", FULL_COMMIT_HASH, CONFIG_NAME))
+
+    def test_cached_file_errors(self):
+        with self.assertRaisesRegex(EnvironmentError, "is not a valid model identifier"):
+            _ = cached_file("tiny-random-bert", CONFIG_NAME)
+
+        with self.assertRaisesRegex(EnvironmentError, "is not a valid git identifier"):
+            _ = cached_file(RANDOM_BERT, CONFIG_NAME, revision="aaaa")
+
+        with self.assertRaisesRegex(EnvironmentError, "does not appear to have a file named"):
+            _ = cached_file(RANDOM_BERT, "conf")
+
+    def test_non_existence_is_cached(self):
+        with self.assertRaisesRegex(EnvironmentError, "does not appear to have a file named"):
+            _ = cached_file(RANDOM_BERT, "conf")
+
+        with open(os.path.join(CACHE_DIR, "refs", "main")) as f:
+            main_commit = f.read()
+        self.assertTrue(os.path.isfile(os.path.join(CACHE_DIR, ".no_exist", main_commit, "conf")))
+
+        path = cached_file(RANDOM_BERT, "conf", _raise_exceptions_for_missing_entries=False)
+        self.assertIsNone(path)
+
+        path = cached_file(RANDOM_BERT, "conf", local_files_only=True, _raise_exceptions_for_missing_entries=False)
+        self.assertIsNone(path)
+
+    def test_has_file(self):
+        self.assertTrue(has_file("hf-internal-testing/tiny-bert-pt-only", WEIGHTS_NAME))
+        self.assertFalse(has_file("hf-internal-testing/tiny-bert-pt-only", TF2_WEIGHTS_NAME))
+        self.assertFalse(has_file("hf-internal-testing/tiny-bert-pt-only", FLAX_WEIGHTS_NAME))
+
+    def test_get_file_from_repo_distant(self):
+        # `get_file_from_repo` returns None if the file does not exist
+        self.assertIsNone(get_file_from_repo("bert-base-cased", "ahah.txt"))
+
+        # The function raises if the repository does not exist.
+        with self.assertRaisesRegex(EnvironmentError, "is not a valid model identifier"):
+            get_file_from_repo("bert-base-case", CONFIG_NAME)
+
+        # The function raises if the revision does not exist.
+        with self.assertRaisesRegex(EnvironmentError, "is not a valid git identifier"):
+            get_file_from_repo("bert-base-cased", CONFIG_NAME, revision="ahaha")
+
+        resolved_file = get_file_from_repo("bert-base-cased", CONFIG_NAME)
+        # The name is the cached name which is not very easy to test, so instead we load the content.
+        config = json.loads(open(resolved_file, "r").read())
+        self.assertEqual(config["hidden_size"], 768)
+
+    def test_get_file_from_repo_local(self):
+        with tempfile.TemporaryDirectory() as tmp_dir:
+            filename = Path(tmp_dir) / "a.txt"
+            filename.touch()
+            self.assertEqual(get_file_from_repo(tmp_dir, "a.txt"), str(filename))
+
+            self.assertIsNone(get_file_from_repo(tmp_dir, "b.txt"))

utils/tests_fetcher.py

@@ -354,7 +354,7 @@ SPECIAL_MODULE_TO_TEST_MAP = {
     "feature_extraction_utils.py": "test_feature_extraction_common.py",
     "file_utils.py": ["utils/test_file_utils.py", "utils/test_model_output.py"],
     "utils/generic.py": ["utils/test_file_utils.py", "utils/test_model_output.py", "utils/test_generic.py"],
-    "utils/hub.py": "utils/test_file_utils.py",
+    "utils/hub.py": "utils/test_hub_utils.py",
     "modelcard.py": "utils/test_model_card.py",
     "modeling_flax_utils.py": "test_modeling_flax_common.py",
     "modeling_tf_utils.py": ["test_modeling_tf_common.py", "utils/test_modeling_tf_core.py"],