feat!: flagSetMetadata in OFREP/ResolveAll, core refactors

Signed-off-by: Todd Baert <todd.baert@dynatrace.com>

config/samples/example_flags.flagd.json

@@ -1,13 +1,20 @@
 {
   "$schema": "https://flagd.dev/schema/v0/flags.json",
+  "metadata": {
+    "flagSetId": "example",
+    "version": "v1"
+  },
   "flags": {
     "myBoolFlag": {
       "state": "ENABLED",
       "variants": {
         "on": true,
         "off": false
       },
-      "defaultVariant": "on"
+      "defaultVariant": "on",
+      "metadata": {
+        "version": "v2"
+      }
     },
     "myStringFlag": {
       "state": "ENABLED",

config/samples/example_flags_secondary.flagd.json

@@ -1,5 +1,8 @@
 {
   "$schema": "https://flagd.dev/schema/v0/flags.json",
+  "metadata": {
+    "version": "v2"
+  },
   "flags": {
     "myBoolFlag": {
       "state": "ENABLED",

core/go.sum

@@ -317,10 +317,6 @@ golang.org/x/crypto v0.18.0/go.mod h1:R0j02AL6hcrfOiy9T4ZYp/rcWeMxM3L6QYxlOuEG1m
 golang.org/x/crypto v0.32.0 h1:euUpcYgM8WcP71gNpTqQCn6rC2t6ULUPiOzfWaXVVfc=
 golang.org/x/crypto v0.32.0/go.mod h1:ZnnJkOaASj8g0AjIduWNlq2NRxL0PlBrbKVyZ6V/Ugc=
 golang.org/x/exp v0.0.0-20190121172915-509febef88a4/go.mod h1:CJ0aWSM057203Lf6IL+f9T1iT9GByDxfZKAQTCR3kQA=
-golang.org/x/exp v0.0.0-20250106191152-7588d65b2ba8 h1:yqrTHse8TCMW1M1ZCP+VAR/l0kKxwaAIqN/il7x4voA=
-golang.org/x/exp v0.0.0-20250106191152-7588d65b2ba8/go.mod h1:tujkw807nyEEAamNbDrEGzRav+ilXA7PCRAd6xsmwiU=
-golang.org/x/exp v0.0.0-20250128144449-3edf0e91c1ae h1:COZdc9Ut6wLq7MO9GIYxfZl4n4ScmgqQLoHocKXrxco=
-golang.org/x/exp v0.0.0-20250128144449-3edf0e91c1ae/go.mod h1:tujkw807nyEEAamNbDrEGzRav+ilXA7PCRAd6xsmwiU=
 golang.org/x/exp v0.0.0-20250128182459-e0ece0dbea4c h1:KL/ZBHXgKGVmuZBZ01Lt57yE5ws8ZPSkkihmEyq7FXc=
 golang.org/x/exp v0.0.0-20250128182459-e0ece0dbea4c/go.mod h1:tujkw807nyEEAamNbDrEGzRav+ilXA7PCRAd6xsmwiU=
 golang.org/x/lint v0.0.0-20181026193005-c67002cb31c3/go.mod h1:UVdnD1Gm6xHRNCYTkRU2/jEulfH38KcIWyp/GAMgvoE=

core/pkg/evaluator/fractional_test.go

@@ -587,7 +587,7 @@ func BenchmarkFractionalEvaluation(b *testing.B) {
 	for name, tt := range tests {
 		b.Run(name, func(b *testing.B) {
 			log := logger.NewLogger(nil, false)
-			je := NewJSON(log, &store.Flags{Flags: tt.flags.Flags})
+			je := NewJSON(log, &store.State{Flags: tt.flags.Flags})
 			for i := 0; i < b.N; i++ {
 				value, variant, reason, _, err := resolve[string](
 					ctx, reqID, tt.flagKey, tt.context, je.evaluateVariant)

core/pkg/evaluator/ievaluator.go

@@ -3,6 +3,7 @@ package evaluator
 import (
 	"context"
 
+	"github.com/open-feature/flagd/core/pkg/model"
 	"github.com/open-feature/flagd/core/pkg/sync"
 )
 
@@ -11,12 +12,12 @@ type AnyValue struct {
 	Variant  string
 	Reason   string
 	FlagKey  string
-	Metadata map[string]interface{}
+	Metadata model.Metadata
 	Error    error
 }
 
 func NewAnyValue(
-	value interface{}, variant string, reason string, flagKey string, metadata map[string]interface{},
+	value interface{}, variant string, reason string, flagKey string, metadata model.Metadata,
 	err error,
 ) AnyValue {
 	return AnyValue{
@@ -34,7 +35,7 @@ IEvaluator is an extension of IResolver, allowing storage updates and retrievals
 */
 type IEvaluator interface {
 	GetState() (string, error)
-	SetState(payload sync.DataSync) (map[string]interface{}, bool, error)
+	SetState(payload sync.DataSync) (model.Metadata, bool, error)
 	IResolver
 }
 
@@ -44,31 +45,31 @@ type IResolver interface {
 		ctx context.Context,
 		reqID string,
 		flagKey string,
-		context map[string]any) (value bool, variant string, reason string, metadata map[string]interface{}, err error)
+		context map[string]any) (value bool, variant string, reason string, metadata model.Metadata, err error)
 	ResolveStringValue(
 		ctx context.Context,
 		reqID string,
 		flagKey string,
 		context map[string]any) (
-		value string, variant string, reason string, metadata map[string]interface{}, err error)
+		value string, variant string, reason string, metadata model.Metadata, err error)
 	ResolveIntValue(
 		ctx context.Context,
 		reqID string,
 		flagKey string,
 		context map[string]any) (
-		value int64, variant string, reason string, metadata map[string]interface{}, err error)
+		value int64, variant string, reason string, metadata model.Metadata, err error)
 	ResolveFloatValue(
 		ctx context.Context,
 		reqID string,
 		flagKey string,
 		context map[string]any) (
-		value float64, variant string, reason string, metadata map[string]interface{}, err error)
+		value float64, variant string, reason string, metadata model.Metadata, err error)
 	ResolveObjectValue(
 		ctx context.Context,
 		reqID string,
 		flagKey string,
 		context map[string]any) (
-		value map[string]any, variant string, reason string, metadata map[string]interface{}, err error)
+		value map[string]any, variant string, reason string, metadata model.Metadata, err error)
 	ResolveAsAnyValue(
 		ctx context.Context,
 		reqID string,
@@ -77,5 +78,5 @@ type IResolver interface {
 	ResolveAllValues(
 		ctx context.Context,
 		reqID string,
-		context map[string]any) (values []AnyValue, err error)
+		context map[string]any) (resolutions []AnyValue, metadata model.Metadata, err error)
 }

core/pkg/evaluator/json.go

@@ -64,13 +64,13 @@ func WithEvaluator(name string, evalFunc func(interface{}, interface{}) interfac
 
 // JSON evaluator
 type JSON struct {
-	store          *store.Flags
+	store          *store.State
 	Logger         *logger.Logger
 	jsonEvalTracer trace.Tracer
 	Resolver
 }
 
-func NewJSON(logger *logger.Logger, s *store.Flags, opts ...JSONEvaluatorOption) *JSON {
+func NewJSON(logger *logger.Logger, s *store.State, opts ...JSONEvaluatorOption) *JSON {
 	logger = logger.WithFields(
 		zap.String("component", "evaluator"),
 		zap.String("evaluator", "json"),
@@ -107,9 +107,9 @@ func (je *JSON) SetState(payload sync.DataSync) (map[string]interface{}, bool, e
 		trace.WithAttributes(attribute.String("feature_flag.sync_type", payload.Type.String())))
 	defer span.End()
 
-	var newFlags Flags
+	var definition Definition
 
-	err := configToFlags(je.Logger, payload.FlagData, &newFlags)
+	err := configToFlagDefinition(je.Logger, payload.FlagData, &definition)
 	if err != nil {
 		span.SetStatus(codes.Error, "flagSync error")
 		span.RecordError(err)
@@ -119,15 +119,16 @@ func (je *JSON) SetState(payload sync.DataSync) (map[string]interface{}, bool, e
 	var events map[string]interface{}
 	var reSync bool
 
+	// TODO: handle other types
 	switch payload.Type {
 	case sync.ALL:
-		events, reSync = je.store.Merge(je.Logger, payload.Source, payload.Selector, newFlags.Flags)
+		events, reSync = je.store.Merge(je.Logger, payload.Source, payload.Selector, definition.Flags, definition.Metadata)
 	case sync.ADD:
-		events = je.store.Add(je.Logger, payload.Source, payload.Selector, newFlags.Flags)
+		events = je.store.Add(je.Logger, payload.Source, payload.Selector, definition.Flags)
 	case sync.UPDATE:
-		events = je.store.Update(je.Logger, payload.Source, payload.Selector, newFlags.Flags)
+		events = je.store.Update(je.Logger, payload.Source, payload.Selector, definition.Flags)
 	case sync.DELETE:
-		events = je.store.DeleteFlags(je.Logger, payload.Source, newFlags.Flags)
+		events = je.store.DeleteFlags(je.Logger, payload.Source, definition.Flags)
 	default:
 		return nil, false, fmt.Errorf("unsupported sync type: %d", payload.Type)
 	}
@@ -156,14 +157,14 @@ func NewResolver(store store.IStore, logger *logger.Logger, jsonEvalTracer trace
 	return Resolver{store: store, Logger: logger, tracer: jsonEvalTracer}
 }
 
-func (je *Resolver) ResolveAllValues(ctx context.Context, reqID string, context map[string]any) ([]AnyValue, error) {
+func (je *Resolver) ResolveAllValues(ctx context.Context, reqID string, context map[string]any) ([]AnyValue, model.Metadata, error) {
 	_, span := je.tracer.Start(ctx, "resolveAll")
 	defer span.End()
 
 	var err error
-	allFlags, err := je.store.GetAll(ctx)
+	allFlags, flagSetMetadata, err := je.store.GetAll(ctx)
 	if err != nil {
-		return nil, fmt.Errorf("error retreiving flags from the store: %w", err)
+		return nil, flagSetMetadata, fmt.Errorf("error retreiving flags from the store: %w", err)
 	}
 
 	values := []AnyValue{}
@@ -195,7 +196,7 @@ func (je *Resolver) ResolveAllValues(ctx context.Context, reqID string, context
 		values = append(values, NewAnyValue(value, variant, reason, flagKey, metadata, err))
 	}
 
-	return values, nil
+	return values, flagSetMetadata, nil
 }
 
 func (je *Resolver) ResolveBooleanValue(
@@ -312,9 +313,7 @@ func resolve[T constraints](ctx context.Context, reqID string, key string, conte
 func (je *Resolver) evaluateVariant(ctx context.Context, reqID string, flagKey string, evalCtx map[string]any) (
 	variant string, variants map[string]interface{}, reason string, metadata map[string]interface{}, err error,
 ) {
-	metadata = map[string]interface{}{}
-
-	flag, ok := je.store.Get(ctx, flagKey)
+	flag, metadata, ok := je.store.Get(ctx, flagKey)
 	if !ok {
 		// flag not found
 		je.Logger.DebugWithID(reqID, fmt.Sprintf("requested flag could not be found: %s", flagKey))
@@ -447,8 +446,8 @@ func loadAndCompileSchema(log *logger.Logger) *gojsonschema.Schema {
 	return compiledSchema
 }
 
-// configToFlags convert string configurations to flags and store them to pointer newFlags
-func configToFlags(log *logger.Logger, config string, newFlags *Flags) error {
+// configToFlagDefinition convert string configurations to flags and store them to pointer newFlags
+func configToFlagDefinition(log *logger.Logger, config string, definition *Definition) error {
 	compiledSchema := loadAndCompileSchema(log)
 
 	flagStringLoader := gojsonschema.NewStringLoader(config)
@@ -467,33 +466,16 @@ func configToFlags(log *logger.Logger, config string, newFlags *Flags) error {
 		return fmt.Errorf("transposing evaluators: %w", err)
 	}
 
-	var configData ConfigWithMetadata
-	err = json.Unmarshal([]byte(transposedConfig), &configData)
+	err = json.Unmarshal([]byte(transposedConfig), &definition)
 	if err != nil {
 		return fmt.Errorf("unmarshalling provided configurations: %w", err)
 	}
 
-	// Assign the flags from the unmarshalled config to the newFlags struct
-	newFlags.Flags = configData.Flags
-
-	// Assign metadata as a map to each flag's metadata
-	for key, flag := range newFlags.Flags {
-		if flag.Metadata == nil {
-			flag.Metadata = make(map[string]interface{})
-		}
-		for metaKey, metaValue := range configData.Metadata {
-			if _, exists := flag.Metadata[metaKey]; !exists {
-				flag.Metadata[metaKey] = metaValue
-			}
-		}
-		newFlags.Flags[key] = flag
-	}
-
-	return validateDefaultVariants(newFlags)
+	return validateDefaultVariants(definition)
 }
 
 // validateDefaultVariants returns an error if any of the default variants aren't valid
-func validateDefaultVariants(flags *Flags) error {
+func validateDefaultVariants(flags *Definition) error {
 	for name, flag := range flags.Flags {
 		if _, ok := flag.Variants[flag.DefaultVariant]; !ok {
 			return fmt.Errorf(

core/pkg/evaluator/json_model.go

@@ -10,7 +10,7 @@ type Evaluators struct {
 	Evaluators map[string]json.RawMessage `json:"$evaluators"`
 }
 
-type ConfigWithMetadata struct {
+type Definition struct {
 	Flags    map[string]model.Flag  `json:"flags"`
 	Metadata map[string]interface{} `json:"metadata"`
 }