fix(influxdb): handles time(auto) like time($interval)

closes #6997

pkg/tsdb/influxdb/query_part.go

@@ -111,7 +111,7 @@ func getDefinedInterval(query *Query, queryContext *tsdb.QueryContext) string {
 
 func functionRenderer(query *Query, queryContext *tsdb.QueryContext, part *QueryPart, innerExpr string) string {
 	for i, param := range part.Params {
-		if param == "$interval" {
+		if param == "$interval" || param == "auto" {
 			if query.Interval != "" {
 				part.Params[i] = getDefinedInterval(query, queryContext)
 			} else {

pkg/tsdb/influxdb/query_part_test.go

@@ -37,7 +37,7 @@ func TestInfluxdbQueryPart(t *testing.T) {
 			So(res, ShouldEqual, "bottom(value, 3)")
 		})
 
-		Convey("render time", func() {
+		Convey("render time with $interval", func() {
 			part, err := NewQueryPart("time", []string{"$interval"})
 			So(err, ShouldBeNil)
 
@@ -45,6 +45,14 @@ func TestInfluxdbQueryPart(t *testing.T) {
 			So(res, ShouldEqual, "time(200ms)")
 		})
 
+		Convey("render time with auto", func() {
+			part, err := NewQueryPart("time", []string{"auto"})
+			So(err, ShouldBeNil)
+
+			res := part.Render(query, queryContext, "")
+			So(res, ShouldEqual, "time(200ms)")
+		})
+
 		Convey("render time interval >10s", func() {
 			part, err := NewQueryPart("time", []string{"$interval"})
 			So(err, ShouldBeNil)