Explore: dont rate-hint on rate queries

public/app/plugins/datasource/prometheus/datasource.ts

@@ -46,7 +46,7 @@ export function determineQueryHints(series: any[], datasource?: any): any[] {
 
     // Check for monotony
     const datapoints: number[][] = s.datapoints;
-    if (datapoints.length > 1) {
+    if (query.indexOf('rate(') === -1 && datapoints.length > 1) {
       let increasing = false;
       const monotonic = datapoints.filter(dp => dp[0] !== null).every((dp, index) => {
         if (index === 0) {

public/app/plugins/datasource/prometheus/specs/datasource.test.ts

@@ -247,6 +247,12 @@ describe('PrometheusDatasource', () => {
       });
     });
 
+    it('returns no rate hint for a monotonously increasing series that already has a rate', () => {
+      const series = [{ datapoints: [[23, 1000], [24, 1001]], query: 'rate(metric[1m])', responseIndex: 0 }];
+      const hints = determineQueryHints(series);
+      expect(hints).toEqual([null]);
+    });
+
     it('returns a rate hint w/o action for a complex monotonously increasing series', () => {
       const series = [{ datapoints: [[23, 1000], [24, 1001]], query: 'sum(metric)', responseIndex: 0 }];
       const hints = determineQueryHints(series);