Don't try to expand GA metrics

src/metabase/query_processor/middleware/expand_macros.clj

@@ -69,8 +69,18 @@
 ;;; |                                                    METRICS                                                     |
 ;;; +----------------------------------------------------------------------------------------------------------------+
 
+(defn- ga-metric?
+  "Is this metric clause not a Metabase Metric, but rather a GA one? E.g. something like [metric ga:users]. We want to
+   ignore those because they're not the same thing at all as MB Metrics and don't correspond to objects in our
+   application DB."
+  [[_ id]]
+  (boolean
+   (when ((some-fn string? keyword?) id)
+     (re-find #"^ga:" (name id)))))
+
 (defn- metric? [aggregation]
-  (is-clause? #{:metric} aggregation))
+  (and (is-clause? #{:metric} aggregation)
+       (not (ga-metric? aggregation))))
 
 (defn- metric-id [metric]
   (when (metric? metric)

test/metabase/query_processor/middleware/expand_macros_test.clj

@@ -179,3 +179,8 @@
                :query    {:source-table (data/id :venues)
                           :aggregation  [["METRIC" (u/get-id metric)]]
                           :breakout     [(ql/breakout (ql/field-id (data/id :venues :price)))]}})))))
+
+;; make sure that we don't try to expand GA "metrics" (#6104)
+(expect
+  {:query {:aggregation [[:metric :ga:users]]}}
+  (#'expand-macros/expand-metrics-and-segments {:query {:aggregation [[:metric :ga:users]]}}))