fix(api): fix empty response for alertList.json

cmd/karma/views.go

@@ -729,7 +729,9 @@ func alertList(w http.ResponseWriter, r *http.Request) {
 	}
 	sort.Strings(sortKeys)
 
-	al := AlertList{}
+	al := AlertList{
+		Alerts: []map[string]string{},
+	}
 	for _, labels := range labelMap {
 		al.Alerts = append(al.Alerts, labels)
 	}

cmd/karma/views_test.go

@@ -3165,6 +3165,12 @@ func TestAlertList(t *testing.T) {
 				},
 			},
 		},
+		{
+			args: "q=foo=bar",
+			alerts: AlertList{
+				Alerts: []map[string]string{},
+			},
+		},
 	}
 
 	mockConfig()