Add ValidationScheme methods IsValidMetricName and IsValidLabelName (#806)

* Add ValidationScheme methods IsValidMetricName and IsValidLabelName

---------

Signed-off-by: Arve Knudsen <[email protected]>

Author: aknuds1

expfmt/decode.go

@@ -93,6 +93,7 @@ func (d *protoDecoder) Decode(v *dto.MetricFamily) error {
 	if err := opts.UnmarshalFrom(d.r, v); err != nil {
 		return err
 	}
+	//nolint:staticcheck // model.IsValidMetricName is deprecated.
 	if !model.IsValidMetricName(model.LabelValue(v.GetName())) {
 		return fmt.Errorf("invalid metric name %q", v.GetName())
 	}
@@ -107,6 +108,7 @@ func (d *protoDecoder) Decode(v *dto.MetricFamily) error {
 			if !model.LabelValue(l.GetValue()).IsValid() {
 				return fmt.Errorf("invalid label value %q", l.GetValue())
 			}
+			//nolint:staticcheck // model.LabelName.IsValid is deprecated.
 			if !model.LabelName(l.GetName()).IsValid() {
 				return fmt.Errorf("invalid label name %q", l.GetName())
 			}

expfmt/openmetrics_create.go

@@ -477,7 +477,7 @@ func writeOpenMetricsNameAndLabelPairs(
 	if name != "" {
 		// If the name does not pass the legacy validity check, we must put the
 		// metric name inside the braces, quoted.
-		if !model.IsValidLegacyMetricName(name) {
+		if !model.LegacyValidation.IsValidMetricName(name) {
 			metricInsideBraces = true
 			err := w.WriteByte(separator)
 			written++

expfmt/text_create.go

@@ -354,7 +354,7 @@ func writeNameAndLabelPairs(
 	if name != "" {
 		// If the name does not pass the legacy validity check, we must put the
 		// metric name inside the braces.
-		if !model.IsValidLegacyMetricName(name) {
+		if !model.LegacyValidation.IsValidMetricName(name) {
 			metricInsideBraces = true
 			err := w.WriteByte(separator)
 			written++
@@ -498,7 +498,7 @@ func writeInt(w enhancedWriter, i int64) (int, error) {
 // writeName writes a string as-is if it complies with the legacy naming
 // scheme, or escapes it in double quotes if not.
 func writeName(w enhancedWriter, name string) (int, error) {
-	if model.IsValidLegacyMetricName(name) {
+	if model.LegacyValidation.IsValidMetricName(name) {
 		return w.WriteString(name)
 	}
 	var written int

model/labels.go

@@ -106,34 +106,21 @@ type LabelName string
 // IsValid returns true iff the name matches the pattern of LabelNameRE when
 // NameValidationScheme is set to LegacyValidation, or valid UTF-8 if
 // NameValidationScheme is set to UTF8Validation.
+//
+// Deprecated: This method should not be used and may be removed in the future.
+// Use [ValidationScheme.IsValidLabelName] instead.
 func (ln LabelName) IsValid() bool {
-	if len(ln) == 0 {
-		return false
-	}
-	switch NameValidationScheme {
-	case LegacyValidation:
-		return ln.IsValidLegacy()
-	case UTF8Validation:
-		return utf8.ValidString(string(ln))
-	default:
-		panic(fmt.Sprintf("Invalid name validation scheme requested: %d", NameValidationScheme))
-	}
+	return NameValidationScheme.IsValidLabelName(string(ln))
 }
 
 // IsValidLegacy returns true iff name matches the pattern of LabelNameRE for
 // legacy names. It does not use LabelNameRE for the check but a much faster
 // hardcoded implementation.
+//
+// Deprecated: This method should not be used and may be removed in the future.
+// Use [LegacyValidation.IsValidLabelName] instead.
 func (ln LabelName) IsValidLegacy() bool {
-	if len(ln) == 0 {
-		return false
-	}
-	for i, b := range ln {
-		// TODO: Apply De Morgan's law. Make sure there are tests for this.
-		if !((b >= 'a' && b <= 'z') || (b >= 'A' && b <= 'Z') || b == '_' || (b >= '0' && b <= '9' && i > 0)) { //nolint:staticcheck
-			return false
-		}
-	}
-	return true
+	return LegacyValidation.IsValidLabelName(string(ln))
 }
 
 // UnmarshalYAML implements the yaml.Unmarshaler interface.

model/labels_test.go

@@ -14,6 +14,7 @@
 package model
 
 import (
+	"fmt"
 	"sort"
 	"testing"
 )
@@ -90,9 +91,9 @@ func BenchmarkLabelValues(b *testing.B) {
 	}
 }
 
-func TestLabelNameIsValid(t *testing.T) {
+func TestValidationScheme_IsLabelNameValid(t *testing.T) {
 	scenarios := []struct {
-		ln          LabelName
+		ln          string
 		legacyValid bool
 		utf8Valid   bool
 	}{
@@ -141,20 +142,39 @@ func TestLabelNameIsValid(t *testing.T) {
 			legacyValid: false,
 			utf8Valid:   false,
 		},
+		{
+			ln:          "",
+			legacyValid: false,
+			utf8Valid:   false,
+		},
 	}
-
 	for _, s := range scenarios {
-		NameValidationScheme = LegacyValidation
-		if s.ln.IsValid() != s.legacyValid {
-			t.Errorf("Expected %v for %q using legacy IsValid method", s.legacyValid, s.ln)
-		}
-		if LabelNameRE.MatchString(string(s.ln)) != s.legacyValid {
-			t.Errorf("Expected %v for %q using legacy regexp match", s.legacyValid, s.ln)
-		}
-		NameValidationScheme = UTF8Validation
-		if s.ln.IsValid() != s.utf8Valid {
-			t.Errorf("Expected %v for %q using UTF-8 IsValid method", s.legacyValid, s.ln)
-		}
+		t.Run(fmt.Sprintf("%s,%t,%t", s.ln, s.legacyValid, s.utf8Valid), func(t *testing.T) {
+			if LegacyValidation.IsValidLabelName(s.ln) != s.legacyValid {
+				t.Errorf("Expected %v for %q using LegacyValidation.IsValidLabelName", s.legacyValid, s.ln)
+			}
+			if LabelNameRE.MatchString(s.ln) != s.legacyValid {
+				t.Errorf("Expected %v for %q using legacy regexp match", s.legacyValid, s.ln)
+			}
+			if UTF8Validation.IsValidLabelName(s.ln) != s.utf8Valid {
+				t.Errorf("Expected %v for %q using UTF8Validation.IsValidLabelName", s.utf8Valid, s.ln)
+			}
+
+			// Test deprecated functions.
+			origScheme := NameValidationScheme
+			t.Cleanup(func() {
+				NameValidationScheme = origScheme
+			})
+			NameValidationScheme = LegacyValidation
+			labelName := LabelName(s.ln)
+			if labelName.IsValid() != s.legacyValid {
+				t.Errorf("Expected %v for %q using legacy IsValid method", s.legacyValid, s.ln)
+			}
+			NameValidationScheme = UTF8Validation
+			if labelName.IsValid() != s.utf8Valid {
+				t.Errorf("Expected %v for %q using UTF-8 IsValid method", s.utf8Valid, s.ln)
+			}
+		})
 	}
 }
 

model/metric.go

@@ -127,6 +127,53 @@ func (s *ValidationScheme) UnmarshalYAML(unmarshal func(any) error) error {
 	return nil
 }
 
+// IsValidMetricName returns whether metricName is valid according to s.
+func (s ValidationScheme) IsValidMetricName(metricName string) bool {
+	switch s {
+	case LegacyValidation:
+		if len(metricName) == 0 {
+			return false
+		}
+		for i, b := range metricName {
+			if !isValidLegacyRune(b, i) {
+				return false
+			}
+		}
+		return true
+	case UTF8Validation:
+		if len(metricName) == 0 {
+			return false
+		}
+		return utf8.ValidString(metricName)
+	default:
+		panic(fmt.Sprintf("Invalid name validation scheme requested: %s", s.String()))
+	}
+}
+
+// IsValidLabelName returns whether labelName is valid according to s.
+func (s ValidationScheme) IsValidLabelName(labelName string) bool {
+	switch s {
+	case LegacyValidation:
+		if len(labelName) == 0 {
+			return false
+		}
+		for i, b := range labelName {
+			// TODO: Apply De Morgan's law. Make sure there are tests for this.
+			if !((b >= 'a' && b <= 'z') || (b >= 'A' && b <= 'Z') || b == '_' || (b >= '0' && b <= '9' && i > 0)) { //nolint:staticcheck
+				return false
+			}
+		}
+		return true
+	case UTF8Validation:
+		if len(labelName) == 0 {
+			return false
+		}
+		return utf8.ValidString(labelName)
+	default:
+		panic(fmt.Sprintf("Invalid name validation scheme requested: %s", s))
+	}
+}
+
 type EscapingScheme int
 
 const (
@@ -230,34 +277,22 @@ func (m Metric) FastFingerprint() Fingerprint {
 // IsValidMetricName returns true iff name matches the pattern of MetricNameRE
 // for legacy names, and iff it's valid UTF-8 if the UTF8Validation scheme is
 // selected.
+//
+// Deprecated: This function should not be used and might be removed in the future.
+// Use [ValidationScheme.IsValidMetricName] instead.
 func IsValidMetricName(n LabelValue) bool {
-	switch NameValidationScheme {
-	case LegacyValidation:
-		return IsValidLegacyMetricName(string(n))
-	case UTF8Validation:
-		if len(n) == 0 {
-			return false
-		}
-		return utf8.ValidString(string(n))
-	default:
-		panic(fmt.Sprintf("Invalid name validation scheme requested: %s", NameValidationScheme.String()))
-	}
+	return NameValidationScheme.IsValidMetricName(string(n))
 }
 
 // IsValidLegacyMetricName is similar to IsValidMetricName but always uses the
 // legacy validation scheme regardless of the value of NameValidationScheme.
 // This function, however, does not use MetricNameRE for the check but a much
 // faster hardcoded implementation.
+//
+// Deprecated: This function should not be used and might be removed in the future.
+// Use [LegacyValidation.IsValidMetricName] instead.
 func IsValidLegacyMetricName(n string) bool {
-	if len(n) == 0 {
-		return false
-	}
-	for i, b := range n {
-		if !isValidLegacyRune(b, i) {
-			return false
-		}
-	}
-	return true
+	return LegacyValidation.IsValidMetricName(n)
 }
 
 // EscapeMetricFamily escapes the given metric names and labels with the given

model/metric_test.go

@@ -15,6 +15,7 @@ package model
 
 import (
 	"errors"
+	"fmt"
 	"strings"
 	"testing"
 
@@ -202,9 +203,9 @@ func TestValidationScheme_UnmarshalYAML(t *testing.T) {
 	}
 }
 
-func TestMetricNameIsLegacyValid(t *testing.T) {
+func TestValidationScheme_IsMetricNameValid(t *testing.T) {
 	scenarios := []struct {
-		mn          LabelValue
+		mn          string
 		legacyValid bool
 		utf8Valid   bool
 	}{
@@ -259,19 +260,35 @@ func TestMetricNameIsLegacyValid(t *testing.T) {
 			utf8Valid:   false,
 		},
 	}
-
 	for _, s := range scenarios {
-		NameValidationScheme = LegacyValidation
-		if IsValidMetricName(s.mn) != s.legacyValid {
-			t.Errorf("Expected %v for %q using legacy IsValidMetricName method", s.legacyValid, s.mn)
-		}
-		if MetricNameRE.MatchString(string(s.mn)) != s.legacyValid {
-			t.Errorf("Expected %v for %q using regexp matching", s.legacyValid, s.mn)
-		}
-		NameValidationScheme = UTF8Validation
-		if IsValidMetricName(s.mn) != s.utf8Valid {
-			t.Errorf("Expected %v for %q using utf-8 IsValidMetricName method", s.legacyValid, s.mn)
-		}
+		t.Run(fmt.Sprintf("%s,%t,%t", s.mn, s.legacyValid, s.utf8Valid), func(t *testing.T) {
+			if LegacyValidation.IsValidMetricName(s.mn) != s.legacyValid {
+				t.Errorf("Expected %v for %q using LegacyValidation.IsValidMetricName", s.legacyValid, s.mn)
+			}
+			if MetricNameRE.MatchString(string(s.mn)) != s.legacyValid {
+				t.Errorf("Expected %v for %q using regexp matching", s.legacyValid, s.mn)
+			}
+			if UTF8Validation.IsValidMetricName(s.mn) != s.utf8Valid {
+				t.Errorf("Expected %v for %q using UTF8Validation.IsValidMetricName", s.utf8Valid, s.mn)
+			}
+
+			// Test deprecated functions.
+			if IsValidLegacyMetricName(s.mn) != s.legacyValid {
+				t.Errorf("Expected %v for %q using IsValidLegacyMetricNames", s.legacyValid, s.mn)
+			}
+			origScheme := NameValidationScheme
+			t.Cleanup(func() {
+				NameValidationScheme = origScheme
+			})
+			NameValidationScheme = LegacyValidation
+			if IsValidMetricName(LabelValue(s.mn)) != s.legacyValid {
+				t.Errorf("Expected %v for %q using legacy IsValidMetricName", s.legacyValid, s.mn)
+			}
+			NameValidationScheme = UTF8Validation
+			if IsValidMetricName(LabelValue(s.mn)) != s.utf8Valid {
+				t.Errorf("Expected %v for %q using utf-8 IsValidMetricName method", s.utf8Valid, s.mn)
+			}
+		})
 	}
 }