[DISCO-4026] fix: Fix casing for engagement lookups (#1361)

Author: ncloudioj

merino/providers/suggest/adm/provider.py

@@ -210,7 +210,7 @@ def normalize_query(self, query: str) -> str:
 
     def _fetch_engagement_metrics(self, suggestion: PyAmpResult) -> EngagementMetrics:
         """Fetch engagement metrics for an AMP suggestion."""
-        advertiser = suggestion.advertiser
+        advertiser = suggestion.advertiser.lower()
         engaged, attempted = 1, 1
         if self.engagement_data and (metrics := self.engagement_data.amp.get(advertiser)):
             attempted = int(metrics.get("impressions", attempted))

tests/unit/providers/suggest/adm/conftest.py

@@ -216,12 +216,12 @@ def fixture_engagement_data() -> EngagementData:
                 "clicks": 5,
             },
             "Example.org": {
-                "advertiser": "Example.org",
+                "advertiser": "example.org",
                 "impressions": 10001,
                 "clicks": 10000,
             },
             "LowEngagement": {
-                "advertiser": "LowEngagement",
+                "advertiser": "lowengagement",
                 "impressions": 9999,
                 "clicks": 5,
             },
@@ -329,7 +329,7 @@ def fixture_adm_with_thompson_single_candidate_below_threshold(
     )
     provider.engagement_data = EngagementData(
         amp={
-            "Example.org": {"click": 10, "impression": 100},
+            "example.org": {"click": 10, "impression": 100},
         },
         amp_aggregated={},
     )