Fix safety check for uptake max age (#370)

checks/remotesettings/uptake_max_age.py

@@ -21,21 +21,16 @@ async def run(
     # Fetch latest results from Redash JSON API.
     rows = await fetch_redash(REDASH_QUERY_ID, api_key)
     rows = [row for row in rows if row["channel"].lower() in channels]
-    if len(rows) == 0:
-        raise ValueError(f"No data for channels {channels}")
 
-    age_percentiles = rows[0]["age_percentiles"]
+    # If no changes were published during this period, then percentiles can be empty.
+    if len(rows) == 0:
+        return True, {"percentiles": "No broadcast data during this period."}
 
     min_timestamp = min(r["min_timestamp"] for r in rows)
     max_timestamp = max(r["max_timestamp"] for r in rows)
-    data = {
-        "min_timestamp": min_timestamp,
-        "max_timestamp": max_timestamp,
-    }
+    data = {"min_timestamp": min_timestamp, "max_timestamp": max_timestamp}
 
-    # If no changes were published during this period, then percentiles can be empty.
-    if len(age_percentiles) == 0:
-        return True, {**data, "percentiles": "No broadcast data during this period."}
+    age_percentiles = rows[0]["age_percentiles"]
 
     percentiles = {}
     for percentile, max_value in max_percentiles.items():

tests/checks/remotesettings/test_uptake_max_age.py

@@ -1,5 +1,3 @@
-import pytest
-
 from checks.remotesettings.uptake_max_age import run
 from tests.utils import patch_async
 
@@ -38,10 +36,10 @@ async def test_positive():
 
 
 async def test_positive_no_data():
-    with patch_async(
-        f"{MODULE}.fetch_redash", return_value=[{**FAKE_ROWS[0], "age_percentiles": []}]
-    ):
-        status, data = await run(api_key="", max_percentiles={"50": 42})
+    with patch_async(f"{MODULE}.fetch_redash", return_value=FAKE_ROWS):
+        status, data = await run(
+            api_key="", max_percentiles={"50": 42}, channels=["aurora"]
+        )
 
     assert status is True
     assert data["percentiles"] == "No broadcast data during this period."
@@ -71,9 +69,3 @@ async def test_filter_by_channel():
         "max_timestamp": "2019-09-16T02:00:00.000",
         "percentiles": {"10": {"value": 100, "max": 99}},
     }
-
-
-async def test_wrong_channel():
-    with patch_async(f"{MODULE}.fetch_redash", return_value=FAKE_ROWS):
-        with pytest.raises(ValueError):
-            await run(api_key="", max_percentiles={"10": 99}, channels=["unknown"])