Allow to use default tags with hub.load() when none are specified.

PiperOrigin-RevId: 276676596

tensorflow_hub/BUILD

@@ -12,14 +12,14 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 # ==============================================================================
-licenses(["notice"])  # Apache 2.0 License
+licenses(["notice"])
+
+load("//tensorflow_hub:protos.bzl", "tf_hub_proto_library")  # buildifier: disable=load-on-top
 
 package(default_visibility = ["//:__subpackages__"])
 
 exports_files(["LICENSE"])
 
-load("//tensorflow_hub:protos.bzl", "tf_hub_proto_library")
-
 # This is the public import users should use.
 py_library(
     name = "tensorflow_hub",
@@ -442,3 +442,21 @@ py_library(
         "//tensorflow_hub:expect_tensorflow_installed",
     ],
 )
+
+py_test(
+    name = "module_v2_test",
+    srcs = ["module_v2_test.py"],
+    data = [
+        "testdata/hub_module_v1_mini",
+        "testdata/saved_model_v2_mini",
+    ],
+    # python_version = "PY2",
+    python_version = "PY3",
+    srcs_version = "PY2AND3",
+    deps = [
+        ":module_v2",
+        ":test_utils",
+        "//tensorflow_hub:expect_tensorflow_installed",
+        ":config",
+    ],
+)

tensorflow_hub/module_v2.py

@@ -20,6 +20,7 @@
 
 import tensorflow as tf
 
+from tensorflow_hub import native_module
 from tensorflow_hub import registry
 from tensorflow_hub import tf_v1
 
@@ -83,9 +84,14 @@ def load(handle, tags=None):
     NotImplementedError: If the code is running against incompatible (1.x)
                          version of TF.
   """
-  if hasattr(tf_v1.saved_model, "load_v2"):
-    module_handle = resolve(handle)
-    return tf_v1.saved_model.load_v2(module_handle, tags=tags)
-  else:
+  if not hasattr(tf_v1.saved_model, "load_v2"):
     raise NotImplementedError("hub.load() is not implemented for TF < 1.14.x, "
                               "Current version: %s" % tf.__version__)
+  module_path = resolve(handle)
+  is_hub_module_v1 = tf.io.gfile.exists(
+      native_module.get_module_proto_path(module_path))
+  if tags is None and is_hub_module_v1:
+      tags = []
+  obj = tf_v1.saved_model.load_v2(module_path, tags=tags)
+  obj._is_hub_module_v1 = is_hub_module_v1  # pylint: disable=protected-access
+  return obj

tensorflow_hub/module_v2_test.py

@@ -0,0 +1,59 @@
+# Copyright 2019 The TensorFlow Hub Authors. 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.
+# ==============================================================================
+"""Tests for tensorflow_hub.module_v2."""
+
+from __future__ import absolute_import
+from __future__ import division
+from __future__ import print_function
+
+# pylint:disable=g-import-not-at-top,g-statement-before-imports
+try:
+  import mock as mock
+except ImportError:
+  import unittest.mock as mock
+# pylint:disable=g-import-not-at-top,g-statement-before-imports
+
+from absl.testing import parameterized
+import tensorflow as tf
+from tensorflow_hub import config
+from tensorflow_hub import module_v2
+from tensorflow_hub import test_utils
+
+# Initialize resolvers and loaders.
+config._run()
+
+
+class ModuleV2Test(tf.test.TestCase, parameterized.TestCase):
+
+  @parameterized.named_parameters(
+      ('v1_implicit_tags', 'hub_module_v1_mini', None, True),
+      ('v1_explicit_tags', 'hub_module_v1_mini', [], True),
+      ('v2_implicit_tags', 'saved_model_v2_mini', None, False),
+      ('v2_explicit_tags', 'saved_model_v2_mini', ['serve'], False),
+      )
+  def test_load(self, module_name, tags, is_hub_module_v1):
+    path = test_utils.get_test_data_path(module_name)
+    m = module_v2.load(path, tags)
+    self.assertEqual(m._is_hub_module_v1, is_hub_module_v1)
+
+  @mock.patch.object(module_v2, 'tf_v1')
+  def test_load_with_old_tensorflow_raises_error(self, tf_v1_mock):
+    tf_v1_mock.saved_model = None
+    with self.assertRaises(NotImplementedError):
+      module_v2.load('dummy_module_name')
+
+
+if __name__ == '__main__':
+  tf.test.main()

tensorflow_hub/testdata/hub_module_v1_mini/tfhub_module.pb

@@ -0,0 +1 @@
+