fix: don't count stats for parent flags, even in get_variant (#300)

This PR fixes an issue where parent flags would have metrics counted when you call get_variant on a child flag. This was due to a missing skip_stats argument in the get_variant method of a feature.

I have added a test and the specific data setup that was reported to cause the issue.

UnleashClient/features/Feature.py

@@ -101,7 +101,7 @@ def get_variant(self, context: dict = None, skip_stats: bool = False) -> dict:
         :param context: Context information
         :return:
         """
-        evaluation_result = self._get_evaluation_result(context)
+        evaluation_result = self._get_evaluation_result(context, skip_stats)
         is_feature_enabled = evaluation_result.enabled
         variant = evaluation_result.variant
         if variant is None or (is_feature_enabled and variant == DISABLED_VARIATION):

tests/unit_tests/test_client.py

@@ -555,6 +555,35 @@ def test_uc_registers_variant_metrics_for_nonexistent_features(unleash_client):
     assert request["bucket"]["toggles"]["nonexistent-flag"]["variants"]["disabled"] == 1
 
 
+@responses.activate
+def test_uc_doesnt_count_metrics_for_dependency_parents(unleash_client):
+    # Set up API
+    responses.add(responses.POST, URL + REGISTER_URL, json={}, status=202)
+    responses.add(
+        responses.GET,
+        URL + FEATURES_URL,
+        json=MOCK_FEATURE_WITH_DEPENDENCIES_RESPONSE,
+        status=200,
+    )
+    responses.add(responses.POST, URL + METRICS_URL, json={}, status=202)
+
+    # Create Unleash client and check initial load
+    unleash_client.initialize_client()
+    time.sleep(1)
+
+    child = "ChildWithVariant"
+    # Check a flag that depends on a parent
+    unleash_client.is_enabled(child)
+    unleash_client.get_variant(child)
+
+    # Verify that the parent doesn't have any metrics registered
+    time.sleep(12)
+    request = json.loads(responses.calls[-1].request.body)
+    assert request["bucket"]["toggles"][child]["yes"] == 2
+    assert request["bucket"]["toggles"][child]["variants"]["childVariant"] == 1
+    assert "Parent" not in request["bucket"]["toggles"]
+
+
 @responses.activate
 def test_uc_disabled_registration(unleash_client_toggle_only):
     unleash_client = unleash_client_toggle_only

tests/utilities/mocks/mock_features.py

@@ -196,6 +196,33 @@
                 }
             ],
         },
+        {
+            "name": "ChildWithVariant",
+            "description": "Feature toggle with variant that depends on a specific variant of the Parent feature toggle",
+            "enabled": True,
+            "strategies": [
+                {
+                    "name": "default",
+                    "parameters": {},
+                    "variants": [
+                        {
+                            "name": "childVariant",
+                            "weight": 1000,
+                            "stickiness": "default",
+                            "weightType": "variable",
+                        }
+                    ],
+                }
+            ],
+            "createdAt": "2018-10-09T06:04:05.667Z",
+            "impressionData": False,
+            "dependencies": [
+                {
+                    "feature": "Parent",
+                    "variants": ["variant1"],
+                }
+            ],
+        },
         {
             "name": "Disabled",
             "description": "Disabled feature toggle",