From f7da9b2db27efc4b16d89251b5965a45327813bf Mon Sep 17 00:00:00 2001
From: Aliaksandr Valialkin <valyala@gmail.com>
Date: Mon, 25 Nov 2019 16:13:13 +0200
Subject: [PATCH] app/vmselect/promql: allow nested parens

---
 app/vmselect/promql/exec_test.go   | 29 +++++++++++++++++++++++++++++
 app/vmselect/promql/parser.go      |  8 ++++++--
 app/vmselect/promql/parser_test.go |  2 ++
 3 files changed, 37 insertions(+), 2 deletions(-)

diff --git a/app/vmselect/promql/exec_test.go b/app/vmselect/promql/exec_test.go
index 16a95c3f0b..424d0c244c 100644
--- a/app/vmselect/promql/exec_test.go
+++ b/app/vmselect/promql/exec_test.go
@@ -4204,6 +4204,35 @@ func TestExecSuccess(t *testing.T) {
 		resultExpected := []netstorage.Result{r1, r2}
 		f(q, resultExpected)
 	})
+	t.Run(`((1),(2,3))`, func(t *testing.T) {
+		t.Parallel()
+		q := `((
+			alias(1, "x1"),
+		),(
+			alias(2, "x2"),
+			alias(3, "x3"),
+		))`
+		r1 := netstorage.Result{
+			MetricName: metricNameExpected,
+			Values:     []float64{1, 1, 1, 1, 1, 1},
+			Timestamps: timestampsExpected,
+		}
+		r1.MetricName.MetricGroup = []byte("x1")
+		r2 := netstorage.Result{
+			MetricName: metricNameExpected,
+			Values:     []float64{2, 2, 2, 2, 2, 2},
+			Timestamps: timestampsExpected,
+		}
+		r2.MetricName.MetricGroup = []byte("x2")
+		r3 := netstorage.Result{
+			MetricName: metricNameExpected,
+			Values:     []float64{3, 3, 3, 3, 3, 3},
+			Timestamps: timestampsExpected,
+		}
+		r3.MetricName.MetricGroup = []byte("x3")
+		resultExpected := []netstorage.Result{r1, r2, r3}
+		f(q, resultExpected)
+	})
 	t.Run(`union(more-than-two)`, func(t *testing.T) {
 		t.Parallel()
 		q := `union(
diff --git a/app/vmselect/promql/parser.go b/app/vmselect/promql/parser.go
index dffd367729..28a75ed91e 100644
--- a/app/vmselect/promql/parser.go
+++ b/app/vmselect/promql/parser.go
@@ -116,13 +116,17 @@ func removeParensExpr(e expr) expr {
 		return fe
 	}
 	if pe, ok := e.(*parensExpr); ok {
+		args := *pe
+		for i, arg := range args {
+			args[i] = removeParensExpr(arg)
+		}
 		if len(*pe) == 1 {
-			return removeParensExpr((*pe)[0])
+			return args[0]
 		}
 		// Treat parensExpr as a function with empty name, i.e. union()
 		fe := &funcExpr{
 			Name: "",
-			Args: *pe,
+			Args: args,
 		}
 		return fe
 	}
diff --git a/app/vmselect/promql/parser_test.go b/app/vmselect/promql/parser_test.go
index 1ef8554cbb..1fab9189e9 100644
--- a/app/vmselect/promql/parser_test.go
+++ b/app/vmselect/promql/parser_test.go
@@ -252,6 +252,8 @@ func TestParsePromQLSuccess(t *testing.T) {
 	another(`(-foo + ((bar) / (baz))) + ((23))`, `((0 - foo) + (bar / baz)) + 23`)
 	another(`(FOO + ((Bar) / (baZ))) + ((23))`, `(FOO + (Bar / baZ)) + 23`)
 	same(`(foo, bar)`)
+	another(`((foo, bar),(baz))`, `((foo, bar), baz)`)
+	same(`(foo, (bar, baz), ((x, y), (z, y), xx))`)
 	another(`1+(foo, bar,)`, `1 + (foo, bar)`)
 	another(`((foo(bar,baz)), (1+(2)+(3,4)+()))`, `(foo(bar, baz), (3 + (3, 4)) + ())`)
 	same(`()`)