FeatureFlags: Use interface rather than manager (#80000)

pkg/services/featuremgmt/manager.go

@@ -174,10 +174,14 @@ func (fm *FeatureManager) LookupFlag(name string) (FeatureFlag, bool) {
 
 // ############# Test Functions #############
 
+func WithFeatures(spec ...any) FeatureToggles {
+	return WithManager(spec...)
+}
+
 // WithFeatures is used to define feature toggles for testing.
 // The arguments are a list of strings that are optionally followed by a boolean value for example:
 // WithFeatures([]any{"my_feature", "other_feature"}) or WithFeatures([]any{"my_feature", true})
-func WithFeatures(spec ...any) *FeatureManager {
+func WithManager(spec ...any) *FeatureManager {
 	count := len(spec)
 	features := make(map[string]*FeatureFlag, count)
 	enabled := make(map[string]bool, count)

pkg/services/featuremgmt/manager_test.go

@@ -9,7 +9,7 @@ import (
 
 func TestFeatureManager(t *testing.T) {
 	t.Run("check testing stubs", func(t *testing.T) {
-		ft := WithFeatures("a", "b", "c")
+		ft := WithManager("a", "b", "c")
 		require.True(t, ft.IsEnabledGlobally("a"))
 		require.True(t, ft.IsEnabledGlobally("b"))
 		require.True(t, ft.IsEnabledGlobally("c"))
@@ -18,7 +18,7 @@ func TestFeatureManager(t *testing.T) {
 		require.Equal(t, map[string]bool{"a": true, "b": true, "c": true}, ft.GetEnabled(context.Background()))
 
 		// Explicit values
-		ft = WithFeatures("a", true, "b", false)
+		ft = WithManager("a", true, "b", false)
 		require.True(t, ft.IsEnabledGlobally("a"))
 		require.False(t, ft.IsEnabledGlobally("b"))
 		require.Equal(t, map[string]bool{"a": true}, ft.GetEnabled(context.Background()))

pkg/services/featuremgmt/models.go

@@ -18,6 +18,10 @@ type FeatureToggles interface {
 	// Use of global feature flags should be limited and careful as they require
 	// a full server restart for a change to take place.
 	IsEnabledGlobally(flag string) bool
+
+	// Get the enabled flags -- this *may* also include disabled flags (with value false)
+	// but it is guaranteed to have the enabled ones listed
+	GetEnabled(ctx context.Context) map[string]bool
 }
 
 // FeatureFlagStage indicates the quality level

pkg/services/featuremgmt/usage_stats_test.go

@@ -8,7 +8,7 @@ import (
 )
 
 func TestFeatureUsageStats(t *testing.T) {
-	featureManagerWithAllFeatures := WithFeatures(
+	featureManagerWithAllFeatures := WithManager(
 		"database_metrics",
 		"live-config",
 		"UPPER_SNAKE_CASE",