Merge pull request #110 from reddit/set_timeout

Set default `timeout` for `path` watched to `30 seconds`

Author: mrlevitas

reddit_decider/__init__.py

@@ -2,6 +2,7 @@
 
 from copy import deepcopy
 from dataclasses import dataclass
+from datetime import timedelta
 from enum import Enum
 from typing import Any
 from typing import Callable
@@ -1209,9 +1210,10 @@ def decider_client_from_config(
         ``path`` (optional)
             The path to the experiment configuration file generated by the
             experiment configuration fetcher daemon.
+            Defaults to :code:`"/var/local/experiments.json"`.
         ``timeout`` (optional)
-            The time that we should wait for the file specified by ``path`` to
-            exist.  Defaults to `None` which is not blocking.
+            The time that we should wait for the file specified by ``path`` to exist.
+            Defaults to blocking for :code:`30` seconds.
         ``backoff`` (optional)
             The base amount of time for exponential backoff when trying to find the
             experiments config file. Defaults to no backoff between tries.
@@ -1231,7 +1233,7 @@ def decider_client_from_config(
         {
             config_prefix: {
                 "path": config.Optional(config.String, default="/var/local/experiments.json"),
-                "timeout": config.Optional(config.Timespan),
+                "timeout": config.Optional(config.Timespan, default=timedelta(seconds=30)),
                 "backoff": config.Optional(config.Timespan),
             }
         },

tests/decider_tests.py

@@ -88,14 +88,14 @@ def setUp(self):
         self.mock_span = mock.MagicMock(spec=ServerSpan)
         self.mock_span.context = None
 
-    def test_make_clients(self, file_watcher_mock):
+    def test_make_client_without_timeout_set(self, file_watcher_mock):
         with create_temp_config_file({}) as f:
             decider_ctx_factory = decider_client_from_config(
                 {"experiments.path": f.name}, self.event_logger
             )
         self.assertIsInstance(decider_ctx_factory, DeciderContextFactory)
         file_watcher_mock.assert_called_once_with(
-            path=f.name, parser=init_decider_parser, timeout=None, backoff=None
+            path=f.name, parser=init_decider_parser, timeout=30.0, backoff=None
         )
 
     def test_timeout(self, file_watcher_mock):