Allow assigning subject from overrides when experiment is not enabled (#11)

* return subject from overrides when experiment not enabled

* make logger callback required

Author: ploomiz

eppo_client/__init__.py

@@ -10,7 +10,7 @@
 from eppo_client.http_client import HttpClient, SdkParams
 from eppo_client.read_write_lock import ReadWriteLock
 
-__version__ = "1.0.2"
+__version__ = "1.0.3"
 
 __client: Optional[EppoClient] = None
 __lock = ReadWriteLock()

eppo_client/client.py

@@ -20,7 +20,7 @@ class EppoClient:
     def __init__(
         self,
         config_requestor: ExperimentConfigurationRequestor,
-        assignment_logger: AssignmentLogger = AssignmentLogger(),
+        assignment_logger: AssignmentLogger,
     ):
         self.__config_requestor = config_requestor
         self.__assignment_logger = assignment_logger
@@ -45,6 +45,9 @@ def get_assignment(
         validate_not_blank("subject_key", subject_key)
         validate_not_blank("experiment_key", experiment_key)
         experiment_config = self.__config_requestor.get_configuration(experiment_key)
+        override = self._get_subject_variation_override(experiment_config, subject_key)
+        if override:
+            return override
         if (
             experiment_config is None
             or not experiment_config.enabled
@@ -56,9 +59,6 @@ def get_assignment(
             )
         ):
             return None
-        override = self._get_subject_variation_override(experiment_config, subject_key)
-        if override:
-            return override
         shard = get_shard(
             "assignment-{}-{}".format(subject_key, experiment_key),
             experiment_config.subject_shards,
@@ -98,10 +98,13 @@ def _shutdown(self):
         self.__poller.stop()
 
     def _get_subject_variation_override(
-        self, experiment_config: ExperimentConfigurationDto, subject: str
+        self, experiment_config: Optional[ExperimentConfigurationDto], subject: str
     ) -> Optional[str]:
         subject_hash = hashlib.md5(subject.encode("utf-8")).hexdigest()
-        if subject_hash in experiment_config.overrides:
+        if (
+            experiment_config is not None
+            and subject_hash in experiment_config.overrides
+        ):
             return experiment_config.overrides[subject_hash]
         return None
 

eppo_client/config.py

@@ -7,7 +7,7 @@
 class Config(SdkBaseModel):
     api_key: str
     base_url: str = "https://eppo.cloud/api"
-    assignment_logger: AssignmentLogger = AssignmentLogger()
+    assignment_logger: AssignmentLogger
 
     def _validate(self):
         validate_not_blank("api_key", self.api_key)

test/client_test.py

@@ -4,6 +4,7 @@
 from unittest.mock import patch
 import httpretty  # type: ignore
 import pytest
+from eppo_client.assignment_logger import AssignmentLogger
 from eppo_client.client import EppoClient
 from eppo_client.config import Config
 from eppo_client.configuration_requestor import (
@@ -43,7 +44,13 @@ def init_fixture():
         MOCK_BASE_URL + "/randomized_assignment/config",
         body=config_response_json,
     )
-    client = init(Config(base_url=MOCK_BASE_URL, api_key="dummy"))
+    client = init(
+        Config(
+            base_url=MOCK_BASE_URL,
+            api_key="dummy",
+            assignment_logger=AssignmentLogger(),
+        )
+    )
     sleep(0.1)  # wait for initialization
     yield
     client._shutdown()
@@ -52,15 +59,19 @@ def init_fixture():
 
 @patch("eppo_client.configuration_requestor.ExperimentConfigurationRequestor")
 def test_assign_blank_experiment(mock_config_requestor):
-    client = EppoClient(config_requestor=mock_config_requestor)
+    client = EppoClient(
+        config_requestor=mock_config_requestor, assignment_logger=AssignmentLogger()
+    )
     with pytest.raises(Exception) as exc_info:
         client.get_assignment("subject-1", "")
     assert exc_info.value.args[0] == "Invalid value for experiment_key: cannot be blank"
 
 
 @patch("eppo_client.configuration_requestor.ExperimentConfigurationRequestor")
 def test_assign_blank_subject(mock_config_requestor):
-    client = EppoClient(config_requestor=mock_config_requestor)
+    client = EppoClient(
+        config_requestor=mock_config_requestor, assignment_logger=AssignmentLogger()
+    )
     with pytest.raises(Exception) as exc_info:
         client.get_assignment("", "experiment-1")
     assert exc_info.value.args[0] == "Invalid value for subject_key: cannot be blank"
@@ -78,7 +89,9 @@ def test_assign_subject_not_in_sample(mock_config_requestor):
         name="recommendation_algo",
         overrides=dict(),
     )
-    client = EppoClient(config_requestor=mock_config_requestor)
+    client = EppoClient(
+        config_requestor=mock_config_requestor, assignment_logger=AssignmentLogger()
+    )
     assert client.get_assignment("user-1", "experiment-key-1") is None
 
 
@@ -139,7 +152,9 @@ def test_assign_subject_with_with_attributes_and_rules(mock_config_requestor):
         overrides=dict(),
         rules=[text_rule],
     )
-    client = EppoClient(config_requestor=mock_config_requestor)
+    client = EppoClient(
+        config_requestor=mock_config_requestor, assignment_logger=AssignmentLogger()
+    )
     assert client.get_assignment("user-1", "experiment-key-1") is None
     assert (
         client.get_assignment(
@@ -165,10 +180,39 @@ def test_with_subject_in_overrides(mock_config_requestor):
         name="recommendation_algo",
         overrides={"d6d7705392bc7af633328bea8c4c6904": "override-variation"},
     )
-    client = EppoClient(config_requestor=mock_config_requestor)
+    client = EppoClient(
+        config_requestor=mock_config_requestor, assignment_logger=AssignmentLogger()
+    )
     assert client.get_assignment("user-1", "experiment-key-1") == "override-variation"
 
 
+@patch("eppo_client.configuration_requestor.ExperimentConfigurationRequestor")
+def test_with_subject_in_overrides_exp_disabled(mock_config_requestor):
+    mock_config_requestor.get_configuration.return_value = ExperimentConfigurationDto(
+        subjectShards=10000,
+        percentExposure=0,
+        enabled=False,
+        variations=[
+            VariationDto(name="control", shardRange=ShardRange(start=0, end=100))
+        ],
+        name="recommendation_algo",
+        overrides={"d6d7705392bc7af633328bea8c4c6904": "override-variation"},
+    )
+    client = EppoClient(
+        config_requestor=mock_config_requestor, assignment_logger=AssignmentLogger()
+    )
+    assert client.get_assignment("user-1", "experiment-key-1") == "override-variation"
+
+
+@patch("eppo_client.configuration_requestor.ExperimentConfigurationRequestor")
+def test_with_null_experiment_config(mock_config_requestor):
+    mock_config_requestor.get_configuration.return_value = None
+    client = EppoClient(
+        config_requestor=mock_config_requestor, assignment_logger=AssignmentLogger()
+    )
+    assert client.get_assignment("user-1", "experiment-key-1") is None
+
+
 @pytest.mark.parametrize("test_case", test_data)
 def test_assign_subject_in_sample(test_case):
     print("---- Test case for {} Experiment".format(test_case["experiment"]))