Add client options. (#8265)

Author: busunkim96

google/api_core/client_options.py

@@ -0,0 +1,48 @@
+# Copyright 2019 Google LLC
+#
+# 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.
+
+"""Client options class.
+
+Client options provide a consistent interface for user options to be defined
+across clients.
+"""
+
+
+class ClientOptions(object):
+    """Client Options used to set options on clients.
+
+    Args:
+        api_endpoint (str): The desired API endpoint, e.g., compute.googleapis.com
+    """
+
+    def __init__(self, api_endpoint=None):
+        self.api_endpoint = api_endpoint
+
+
+def from_dict(options):
+    """Construct a client options object from a dictionary.
+
+    Args:
+        options (dict): A dictionary with client options.
+    """
+
+    client_options = ClientOptions()
+
+    for key, value in options.items():
+        if hasattr(client_options, key):
+            setattr(client_options, key, value)
+        else:
+            raise ValueError("ClientOptions does not accept an option '" + key + "'")
+
+    return client_options

tests/unit/test_client_options.py

@@ -0,0 +1,36 @@
+# Copyright 2019 Google LLC
+#
+# 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 pytest
+
+from google.api_core import client_options
+
+
+def test_constructor():
+    options = client_options.ClientOptions(api_endpoint="foo.googleapis.com")
+
+    assert options.api_endpoint == "foo.googleapis.com"
+
+
+def test_from_dict():
+    options = client_options.from_dict({"api_endpoint": "foo.googleapis.com"})
+
+    assert options.api_endpoint == "foo.googleapis.com"
+
+
+def test_from_dict_bad_argument():
+    with pytest.raises(ValueError):
+        client_options.from_dict(
+            {"api_endpoint": "foo.googleapis.com", "bad_arg": "1234"}
+        )