From 6f67e0b56bfa546309df88de156a4f82d21b574e Mon Sep 17 00:00:00 2001
From: Aliaksandr Valialkin <valyala@gmail.com>
Date: Wed, 25 Dec 2019 22:19:34 +0200
Subject: [PATCH] lib/metricsq: add ExpandWithExprs

---
 app/vmselect/promql/exec.go      | 11 --------
 app/vmselect/promql/exec_test.go | 38 ----------------------------
 lib/metricsql/utils.go           | 12 +++++++++
 lib/metricsql/utils_test.go      | 43 ++++++++++++++++++++++++++++++++
 4 files changed, 55 insertions(+), 49 deletions(-)
 create mode 100644 lib/metricsql/utils.go
 create mode 100644 lib/metricsql/utils_test.go

diff --git a/app/vmselect/promql/exec.go b/app/vmselect/promql/exec.go
index ca749e8de..1c248d799 100644
--- a/app/vmselect/promql/exec.go
+++ b/app/vmselect/promql/exec.go
@@ -19,17 +19,6 @@ var logSlowQueryDuration = flag.Duration("search.logSlowQueryDuration", 5*time.S
 
 var slowQueries = metrics.NewCounter(`vm_slow_queries_total`)
 
-// ExpandWithExprs expands WITH expressions inside q and returns the resulting
-// PromQL without WITH expressions.
-func ExpandWithExprs(q string) (string, error) {
-	e, err := parsePromQLWithCache(q)
-	if err != nil {
-		return "", err
-	}
-	buf := e.AppendString(nil)
-	return string(buf), nil
-}
-
 // Exec executes q for the given ec.
 func Exec(ec *EvalConfig, q string, isFirstPointOnly bool) ([]netstorage.Result, error) {
 	if *logSlowQueryDuration > 0 {
diff --git a/app/vmselect/promql/exec_test.go b/app/vmselect/promql/exec_test.go
index aadbbb33c..a46314e23 100644
--- a/app/vmselect/promql/exec_test.go
+++ b/app/vmselect/promql/exec_test.go
@@ -8,44 +8,6 @@ import (
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/storage"
 )
 
-func TestExpandWithExprsSuccess(t *testing.T) {
-	f := func(q, qExpected string) {
-		t.Helper()
-		for i := 0; i < 3; i++ {
-			qExpanded, err := ExpandWithExprs(q)
-			if err != nil {
-				t.Fatalf("unexpected error when expanding %q: %s", q, err)
-			}
-			if qExpanded != qExpected {
-				t.Fatalf("unexpected expanded expression for %q;\ngot\n%q\nwant\n%q", q, qExpanded, qExpected)
-			}
-		}
-	}
-
-	f(`1`, `1`)
-	f(`foobar`, `foobar`)
-	f(`with (x = 1) x+x`, `2`)
-	f(`with (f(x) = x*x) 3+f(2)+2`, `9`)
-}
-
-func TestExpandWithExprsError(t *testing.T) {
-	f := func(q string) {
-		t.Helper()
-		for i := 0; i < 3; i++ {
-			qExpanded, err := ExpandWithExprs(q)
-			if err == nil {
-				t.Fatalf("expecting non-nil error when expanding %q", q)
-			}
-			if qExpanded != "" {
-				t.Fatalf("unexpected non-empty qExpanded=%q", qExpanded)
-			}
-		}
-	}
-
-	f(``)
-	f(`  with (`)
-}
-
 func TestExecSuccess(t *testing.T) {
 	start := int64(1000e3)
 	end := int64(2000e3)
diff --git a/lib/metricsql/utils.go b/lib/metricsql/utils.go
new file mode 100644
index 000000000..3e3fa8d6e
--- /dev/null
+++ b/lib/metricsql/utils.go
@@ -0,0 +1,12 @@
+package metricsql
+
+// ExpandWithExprs expands WITH expressions inside q and returns the resulting
+// PromQL without WITH expressions.
+func ExpandWithExprs(q string) (string, error) {
+	e, err := Parse(q)
+	if err != nil {
+		return "", err
+	}
+	buf := e.AppendString(nil)
+	return string(buf), nil
+}
diff --git a/lib/metricsql/utils_test.go b/lib/metricsql/utils_test.go
new file mode 100644
index 000000000..ce08034a2
--- /dev/null
+++ b/lib/metricsql/utils_test.go
@@ -0,0 +1,43 @@
+package metricsql
+
+import (
+	"testing"
+)
+
+func TestExpandWithExprsSuccess(t *testing.T) {
+	f := func(q, qExpected string) {
+		t.Helper()
+		for i := 0; i < 3; i++ {
+			qExpanded, err := ExpandWithExprs(q)
+			if err != nil {
+				t.Fatalf("unexpected error when expanding %q: %s", q, err)
+			}
+			if qExpanded != qExpected {
+				t.Fatalf("unexpected expanded expression for %q;\ngot\n%q\nwant\n%q", q, qExpanded, qExpected)
+			}
+		}
+	}
+
+	f(`1`, `1`)
+	f(`foobar`, `foobar`)
+	f(`with (x = 1) x+x`, `2`)
+	f(`with (f(x) = x*x) 3+f(2)+2`, `9`)
+}
+
+func TestExpandWithExprsError(t *testing.T) {
+	f := func(q string) {
+		t.Helper()
+		for i := 0; i < 3; i++ {
+			qExpanded, err := ExpandWithExprs(q)
+			if err == nil {
+				t.Fatalf("expecting non-nil error when expanding %q", q)
+			}
+			if qExpanded != "" {
+				t.Fatalf("unexpected non-empty qExpanded=%q", qExpanded)
+			}
+		}
+	}
+
+	f(``)
+	f(`  with (`)
+}