Address maintainer feedback: add validations and remove changelog

- Remove changelog entry (mdatagen is internal tool)

- Add validation: feature gates must be sorted by ID

- Add validation: each feature gate must have reference_url

- Add validation: ID must match regex ^[0-9a-zA-Z.]*$

- Add comprehensive tests for all validations

- Revert unrelated formatting changes to package_test.go.tmpl

Author: sAchin-680

.chloggen/mdatagen-featuregates-docs.yaml

@@ -280,6 +280,14 @@ func validateEvents(events map[EventName]Event, attributes map[AttributeName]Att
 func (md *Metadata) validateFeatureGates() error {
 	var errs error
 	seen := make(map[FeatureGateID]bool)
+	idRegexp := regexp.MustCompile(`^[0-9a-zA-Z.]*$`)
+
+	// Validate that feature gates are sorted by ID
+	if !slices.IsSortedFunc(md.FeatureGates, func(a, b FeatureGate) int {
+		return strings.Compare(string(a.ID), string(b.ID))
+	}) {
+		errs = errors.Join(errs, errors.New("feature gates must be sorted by ID"))
+	}
 
 	for i, gate := range md.FeatureGates {
 		// Validate gate ID is not empty
@@ -288,6 +296,11 @@ func (md *Metadata) validateFeatureGates() error {
 			continue
 		}
 
+		// Validate ID follows the allowed character pattern
+		if !idRegexp.MatchString(string(gate.ID)) {
+			errs = errors.Join(errs, fmt.Errorf(`feature gate "%v": ID contains invalid characters, must match ^[0-9a-zA-Z.]*$`, gate.ID))
+		}
+
 		// Check for duplicate IDs
 		if seen[gate.ID] {
 			errs = errors.Join(errs, fmt.Errorf(`feature gate "%v": duplicate ID`, gate.ID))
@@ -300,6 +313,11 @@ func (md *Metadata) validateFeatureGates() error {
 			errs = errors.Join(errs, fmt.Errorf(`feature gate "%v": description is required`, gate.ID))
 		}
 
+		// Validate that each feature gate has a reference link
+		if gate.ReferenceURL == "" {
+			errs = errors.Join(errs, fmt.Errorf(`feature gate "%v": reference_url is required`, gate.ID))
+		}
+
 		// Validate stage is one of the allowed values
 		validStages := map[FeatureGateStage]bool{
 			FeatureGateStageAlpha:      true,

cmd/mdatagen/internal/metadata.go

@@ -343,11 +343,12 @@ func TestValidateFeatureGates(t *testing.T) {
 		{
 			name: "valid stable gate with to_version",
 			featureGate: FeatureGate{
-				ID:          "component.stable",
-				Description: "Stable feature gate",
-				Stage:       FeatureGateStageStable,
-				FromVersion: "v0.90.0",
-				ToVersion:   "v0.95.0",
+				ID:           "component.stable",
+				Description:  "Stable feature gate",
+				Stage:        FeatureGateStageStable,
+				FromVersion:  "v0.90.0",
+				ToVersion:    "v0.95.0",
+				ReferenceURL: "https://example.com",
 			},
 		},
 		{
@@ -410,6 +411,27 @@ func TestValidateFeatureGates(t *testing.T) {
 			},
 			wantErr: `to_version is required for deprecated stage gates`,
 		},
+		{
+			name: "missing reference_url",
+			featureGate: FeatureGate{
+				ID:          "component.feature",
+				Description: "Test feature",
+				Stage:       FeatureGateStageAlpha,
+				FromVersion: "v0.100.0",
+			},
+			wantErr: `reference_url is required`,
+		},
+		{
+			name: "invalid characters in ID",
+			featureGate: FeatureGate{
+				ID:           "component.feature@invalid",
+				Description:  "Test feature",
+				Stage:        FeatureGateStageAlpha,
+				FromVersion:  "v0.100.0",
+				ReferenceURL: "https://example.com",
+			},
+			wantErr: `ID contains invalid characters`,
+		},
 	}
 
 	for _, tt := range tests {
@@ -461,3 +483,25 @@ func TestValidateFeatureGatesDuplicateID(t *testing.T) {
 	require.Error(t, err)
 	assert.ErrorContains(t, err, "duplicate ID")
 }
+
+func TestValidateFeatureGatesNotSorted(t *testing.T) {
+	md := &Metadata{
+		FeatureGates: []FeatureGate{
+			{
+				ID:           "component.zebra",
+				Description:  "Test feature",
+				Stage:        FeatureGateStageAlpha,
+				ReferenceURL: "https://example.com",
+			},
+			{
+				ID:           "component.alpha",
+				Description:  "Another feature",
+				Stage:        FeatureGateStageAlpha,
+				ReferenceURL: "https://example.com",
+			},
+		},
+	}
+	err := md.validateFeatureGates()
+	require.Error(t, err)
+	assert.ErrorContains(t, err, "feature gates must be sorted by ID")
+}

cmd/mdatagen/internal/metadata_test.go

@@ -7,8 +7,8 @@ import (
     "os"
     {{- end }}
 	"testing"
-    {{- if not .Tests.GoLeak.Skip }}
 
+    {{- if not .Tests.GoLeak.Skip }}
     "go.uber.org/goleak"
     {{- end }}
 )