lib/promrelabel: export MustParseMetricWithLabels function, which can be used for simplifying tests

lib/promrelabel/if_expression_test.go

@@ -3,12 +3,8 @@ package promrelabel
 import (
 	"bytes"
 	"encoding/json"
-	"fmt"
-	"strings"
 	"testing"
 
-	"github.com/VictoriaMetrics/VictoriaMetrics/lib/prompbmarshal"
-	"github.com/VictoriaMetrics/VictoriaMetrics/lib/protoparser/prometheus"
 	"gopkg.in/yaml.v2"
 )
 
@@ -125,10 +121,7 @@ func TestIfExpressionMatch(t *testing.T) {
 		if err := yaml.UnmarshalStrict([]byte(ifExpr), &ie); err != nil {
 			t.Fatalf("unexpected error during unmarshal: %s", err)
 		}
-		labels, err := parseMetricWithLabels(metricWithLabels)
-		if err != nil {
-			t.Fatalf("cannot parse %s: %s", metricWithLabels, err)
-		}
+		labels := MustParseMetricWithLabels(metricWithLabels)
 		if !ie.Match(labels) {
 			t.Fatalf("unexpected mismatch of ifExpr=%s for %s", ifExpr, metricWithLabels)
 		}
@@ -162,10 +155,7 @@ func TestIfExpressionMismatch(t *testing.T) {
 		if err := yaml.UnmarshalStrict([]byte(ifExpr), &ie); err != nil {
 			t.Fatalf("unexpected error during unmarshal: %s", err)
 		}
-		labels, err := parseMetricWithLabels(metricWithLabels)
-		if err != nil {
-			t.Fatalf("cannot parse %s: %s", metricWithLabels, err)
-		}
+		labels := MustParseMetricWithLabels(metricWithLabels)
 		if ie.Match(labels) {
 			t.Fatalf("unexpected match of ifExpr=%s for %s", ifExpr, metricWithLabels)
 		}
@@ -187,40 +177,3 @@ func TestIfExpressionMismatch(t *testing.T) {
 	f(`'{foo!~"bar|"}'`, `abc`)
 	f(`'{foo!~"bar|"}'`, `abc{foo="bar"}`)
 }
-
-func parseMetricWithLabels(metricWithLabels string) ([]prompbmarshal.Label, error) {
-	stripDummyMetric := false
-	if strings.HasPrefix(metricWithLabels, "{") {
-		// Add a dummy metric name, since the parser needs it
-		metricWithLabels = "dummy_metric" + metricWithLabels
-		stripDummyMetric = true
-	}
-	// add a value to metricWithLabels, so it could be parsed by prometheus protocol parser.
-	s := metricWithLabels + " 123"
-	var rows prometheus.Rows
-	var err error
-	rows.UnmarshalWithErrLogger(s, func(s string) {
-		err = fmt.Errorf("error during metric parse: %s", s)
-	})
-	if err != nil {
-		return nil, err
-	}
-	if len(rows.Rows) != 1 {
-		return nil, fmt.Errorf("unexpected number of rows parsed; got %d; want 1", len(rows.Rows))
-	}
-	r := rows.Rows[0]
-	var lfs []prompbmarshal.Label
-	if !stripDummyMetric {
-		lfs = append(lfs, prompbmarshal.Label{
-			Name:  "__name__",
-			Value: r.Metric,
-		})
-	}
-	for _, tag := range r.Tags {
-		lfs = append(lfs, prompbmarshal.Label{
-			Name:  tag.Key,
-			Value: tag.Value,
-		})
-	}
-	return lfs, nil
-}

lib/promrelabel/relabel_test.go

@@ -77,10 +77,7 @@ func TestApplyRelabelConfigs(t *testing.T) {
 		if err != nil {
 			t.Fatalf("cannot parse %q: %s", config, err)
 		}
-		labels, err := parseMetricWithLabels(metric)
-		if err != nil {
-			t.Fatalf("cannot parse %s: %s", metric, err)
-		}
+		labels := MustParseMetricWithLabels(metric)
 		resultLabels := pcs.Apply(labels, 0, isFinalize)
 		result := labelsToString(resultLabels)
 		if result != resultExpected {
@@ -696,10 +693,7 @@ func TestApplyRelabelConfigs(t *testing.T) {
 func TestFinalizeLabels(t *testing.T) {
 	f := func(metric, resultExpected string) {
 		t.Helper()
-		labels, err := parseMetricWithLabels(metric)
-		if err != nil {
-			t.Fatalf("cannot parse %s: %s", metric, err)
-		}
+		labels := MustParseMetricWithLabels(metric)
 		resultLabels := FinalizeLabels(nil, labels)
 		result := labelsToString(resultLabels)
 		if result != resultExpected {
@@ -715,10 +709,7 @@ func TestFinalizeLabels(t *testing.T) {
 func TestRemoveMetaLabels(t *testing.T) {
 	f := func(metric, resultExpected string) {
 		t.Helper()
-		labels, err := parseMetricWithLabels(metric)
-		if err != nil {
-			t.Fatalf("cannot parse %s: %s", metric, err)
-		}
+		labels := MustParseMetricWithLabels(metric)
 		resultLabels := RemoveMetaLabels(nil, labels)
 		result := labelsToString(resultLabels)
 		if result != resultExpected {
@@ -734,10 +725,7 @@ func TestRemoveMetaLabels(t *testing.T) {
 func TestFillLabelReferences(t *testing.T) {
 	f := func(replacement, metric, resultExpected string) {
 		t.Helper()
-		labels, err := parseMetricWithLabels(metric)
-		if err != nil {
-			t.Fatalf("cannot parse %s: %s", metric, err)
-		}
+		labels := MustParseMetricWithLabels(metric)
 		result := fillLabelReferences(nil, replacement, labels)
 		if string(result) != resultExpected {
 			t.Fatalf("unexpected result; got\n%q\nwant\n%q", result, resultExpected)

lib/promrelabel/util.go

@@ -0,0 +1,50 @@
+package promrelabel
+
+import (
+	"fmt"
+	"strings"
+
+	"github.com/VictoriaMetrics/VictoriaMetrics/lib/logger"
+	"github.com/VictoriaMetrics/VictoriaMetrics/lib/prompbmarshal"
+	"github.com/VictoriaMetrics/VictoriaMetrics/lib/protoparser/prometheus"
+)
+
+// MustParseMetricWithLabels parses s, which can have the form `metric{labels}`.
+//
+// This function is indended mostly for tests.
+func MustParseMetricWithLabels(metricWithLabels string) []prompbmarshal.Label {
+	stripDummyMetric := false
+	if strings.HasPrefix(metricWithLabels, "{") {
+		// Add a dummy metric name, since the parser needs it
+		metricWithLabels = "dummy_metric" + metricWithLabels
+		stripDummyMetric = true
+	}
+	// add a value to metricWithLabels, so it could be parsed by prometheus protocol parser.
+	s := metricWithLabels + " 123"
+	var rows prometheus.Rows
+	var err error
+	rows.UnmarshalWithErrLogger(s, func(s string) {
+		err = fmt.Errorf("error during metric parse: %s", s)
+	})
+	if err != nil {
+		logger.Panicf("BUG: cannot parse %q: %s", metricWithLabels, err)
+	}
+	if len(rows.Rows) != 1 {
+		logger.Panicf("BUG: unexpected number of rows parsed; got %d; want 1", len(rows.Rows))
+	}
+	r := rows.Rows[0]
+	var lfs []prompbmarshal.Label
+	if !stripDummyMetric {
+		lfs = append(lfs, prompbmarshal.Label{
+			Name:  "__name__",
+			Value: r.Metric,
+		})
+	}
+	for _, tag := range r.Tags {
+		lfs = append(lfs, prompbmarshal.Label{
+			Name:  tag.Key,
+			Value: tag.Value,
+		})
+	}
+	return lfs
+}