feat: wip pass yaml as filetype to FilePathSync

- check `yaml.Unmarshal` not able to `Unmarshal` to `json.rawMessage` which is just `[]byte` with `MarshalJSON` and `UnmarshalJSON`
- `FileTypeEvaluator` didn't turn out to be such a good idea because we are reliant on `gojsonschema` to test json schema
- add `example_flags.yaml` file based on `examples_flags.json`
refactor: remove traces of `FileTypeEvaluator`

Signed-off-by: Suraj Banakar <surajrbanakar@gmail.com>

config/samples/example_flags.yaml

@@ -0,0 +1,88 @@
+flags:
+  myBoolFlag:
+    state: ENABLED
+    variants:
+      'on': true
+      'off': false
+    defaultVariant: 'on'
+  myStringFlag:
+    state: ENABLED
+    variants:
+      key1: val1
+      key2: val2
+    defaultVariant: key1
+  myFloatFlag:
+    state: ENABLED
+    variants:
+      one: 1.23
+      two: 2.34
+    defaultVariant: one
+  myIntFlag:
+    state: ENABLED
+    variants:
+      one: 1
+      two: 2
+    defaultVariant: one
+  myObjectFlag:
+    state: ENABLED
+    variants:
+      object1:
+        key: val
+      object2:
+        key: true
+    defaultVariant: object1
+  isColorYellow:
+    state: ENABLED
+    variants:
+      'on': true
+      'off': false
+    defaultVariant: 'off'
+    targeting:
+      if:
+      - "==":
+        - var:
+          - color
+        - yellow
+      - 'on'
+      - 'off'
+  fibAlgo:
+    variants:
+      recursive: recursive
+      memo: memo
+      loop: loop
+      binet: binet
+    defaultVariant: recursive
+    state: ENABLED
+    targeting:
+      if:
+      - "$ref": emailWithFaas
+      - binet
+      - null
+  headerColor:
+    variants:
+      red: "#FF0000"
+      blue: "#0000FF"
+      green: "#00FF00"
+      yellow: "#FFFF00"
+    defaultVariant: red
+    state: ENABLED
+    targeting:
+      if:
+      - "$ref": emailWithFaas
+      - fractionalEvaluation:
+        - email
+        - - red
+          - 25
+        - - blue
+          - 25
+        - - green
+          - 25
+        - - yellow
+          - 25
+      - null
+"$evaluators":
+  emailWithFaas:
+    in:
+    - "@faas.com"
+    - var:
+      - email

go.mod

@@ -27,6 +27,7 @@ require (
 	golang.org/x/sync v0.0.0-20220929204114-8fcdb60fdcc0
 	google.golang.org/grpc v1.49.0
 	google.golang.org/protobuf v1.28.1
+	gopkg.in/yaml.v2 v2.4.0
 	k8s.io/api v0.25.2
 	k8s.io/apimachinery v0.25.2
 	k8s.io/client-go v0.25.2
@@ -89,7 +90,6 @@ require (
 	google.golang.org/genproto v0.0.0-20220930163606-c98284e70a91 // indirect
 	gopkg.in/inf.v0 v0.9.1 // indirect
 	gopkg.in/ini.v1 v1.67.0 // indirect
-	gopkg.in/yaml.v2 v2.4.0 // indirect
 	gopkg.in/yaml.v3 v3.0.1 // indirect
 	k8s.io/klog/v2 v2.80.1 // indirect
 	k8s.io/kube-openapi v0.0.0-20220928191237-829ce0c27909 // indirect

pkg/eval/filetype_evaluator.go → pkg/eval/json_evaluator.go

@@ -16,16 +16,9 @@ import (
 	"google.golang.org/protobuf/types/known/structpb"
 )
 
-type FileTypeEvaluator struct {
+type JSONEvaluator struct {
 	state  Flags
 	Logger *log.Entry
-	MUaler interface{}
-}
-
-// MUaler is short for `MarshalerUnmarshaler`
-type MUaler interface {
-	Marshal(v interface{}) ([]byte, error)
-	Unmarshal(data []byte, v interface{}) error
 }
 
 type constraints interface {
@@ -36,15 +29,15 @@ const (
 	Disabled = "DISABLED"
 )
 
-func (je *FileTypeEvaluator) GetState() (string, error) {
+func (je *JSONEvaluator) GetState() (string, error) {
 	data, err := json.Marshal(&je.state)
 	if err != nil {
 		return "", err
 	}
 	return string(data), nil
 }
 
-func (je *FileTypeEvaluator) SetState(source string, state string) ([]StateChangeNotification, error) {
+func (je *JSONEvaluator) SetState(source string, state string) ([]StateChangeNotification, error) {
 	schemaLoader := gojsonschema.NewStringLoader(schema.FlagdDefinitions)
 	flagStringLoader := gojsonschema.NewStringLoader(state)
 	result, err := gojsonschema.Validate(schemaLoader, flagStringLoader)
@@ -98,7 +91,7 @@ func resolve[T constraints](key string, context *structpb.Struct,
 	return value, variant, reason, nil
 }
 
-func (je *FileTypeEvaluator) ResolveBooleanValue(flagKey string, context *structpb.Struct) (
+func (je *JSONEvaluator) ResolveBooleanValue(flagKey string, context *structpb.Struct) (
 	value bool,
 	variant string,
 	reason string,
@@ -107,7 +100,7 @@ func (je *FileTypeEvaluator) ResolveBooleanValue(flagKey string, context *struct
 	return resolve[bool](flagKey, context, je.evaluateVariant, je.state.Flags[flagKey].Variants)
 }
 
-func (je *FileTypeEvaluator) ResolveStringValue(flagKey string, context *structpb.Struct) (
+func (je *JSONEvaluator) ResolveStringValue(flagKey string, context *structpb.Struct) (
 	value string,
 	variant string,
 	reason string,
@@ -116,7 +109,7 @@ func (je *FileTypeEvaluator) ResolveStringValue(flagKey string, context *structp
 	return resolve[string](flagKey, context, je.evaluateVariant, je.state.Flags[flagKey].Variants)
 }
 
-func (je *FileTypeEvaluator) ResolveFloatValue(flagKey string, context *structpb.Struct) (
+func (je *JSONEvaluator) ResolveFloatValue(flagKey string, context *structpb.Struct) (
 	value float64,
 	variant string,
 	reason string,
@@ -126,7 +119,7 @@ func (je *FileTypeEvaluator) ResolveFloatValue(flagKey string, context *structpb
 	return
 }
 
-func (je *FileTypeEvaluator) ResolveIntValue(flagKey string, context *structpb.Struct) (
+func (je *JSONEvaluator) ResolveIntValue(flagKey string, context *structpb.Struct) (
 	value int64,
 	variant string,
 	reason string,
@@ -138,7 +131,7 @@ func (je *FileTypeEvaluator) ResolveIntValue(flagKey string, context *structpb.S
 	return
 }
 
-func (je *FileTypeEvaluator) ResolveObjectValue(flagKey string, context *structpb.Struct) (
+func (je *JSONEvaluator) ResolveObjectValue(flagKey string, context *structpb.Struct) (
 	value map[string]any,
 	variant string,
 	reason string,
@@ -148,7 +141,7 @@ func (je *FileTypeEvaluator) ResolveObjectValue(flagKey string, context *structp
 }
 
 // runs the rules (if defined) to determine the variant, otherwise falling through to the default
-func (je *FileTypeEvaluator) evaluateVariant(
+func (je *JSONEvaluator) evaluateVariant(
 	flagKey string,
 	context *structpb.Struct,
 ) (variant string, reason string, err error) {
@@ -211,7 +204,7 @@ func validateDefaultVariants(flags Flags) error {
 	return nil
 }
 
-func (je *FileTypeEvaluator) transposeEvaluators(state string) (string, error) {
+func (je *JSONEvaluator) transposeEvaluators(state string) (string, error) {
 	var evaluators Evaluators
 	if err := json.Unmarshal([]byte(state), &evaluators); err != nil {
 		return "", fmt.Errorf("unmarshal: %w", err)

pkg/eval/json_evaluator_model.go

@@ -5,12 +5,17 @@ import (
 	"reflect"
 )
 
+type FlagsAndEvaluators struct {
+	Flags      map[string]Flag            `json:"flags" yaml:"flags"`
+	Evaluators map[string]json.RawMessage `json:"$evaluators" yaml:"$evaluators"`
+}
+
 type Flags struct {
-	Flags map[string]Flag `json:"flags"`
+	Flags map[string]Flag `json:"flags" yaml:"flags"`
 }
 
 type Evaluators struct {
-	Evaluators map[string]json.RawMessage `json:"$evaluators"`
+	Evaluators map[string]json.RawMessage `json:"$evaluators" yaml:"$evaluators"`
 }
 
 func (f Flags) Merge(source string, ff Flags) (Flags, []StateChangeNotification) {
@@ -52,9 +57,9 @@ func (f Flags) Merge(source string, ff Flags) (Flags, []StateChangeNotification)
 }
 
 type Flag struct {
-	State          string          `json:"state"`
-	DefaultVariant string          `json:"defaultVariant"`
-	Variants       map[string]any  `json:"variants"`
-	Targeting      json.RawMessage `json:"targeting"`
-	Source         string          `json:"source"`
+	State          string          `json:"state" yaml:"state"`
+	DefaultVariant string          `json:"defaultVariant" yaml:"defaultVariant"`
+	Variants       map[string]any  `json:"variants" yaml:"variants"`
+	Targeting      json.RawMessage `json:"targeting" yaml:"targeting"`
+	Source         string          `json:"source" yaml:"source"`
 }

pkg/runtime/from_config.go

@@ -52,19 +52,12 @@ func (r *Runtime) setEvaluatorFromConfig() error {
 	switch r.config.Evaluator {
 	case "json":
 
-		r.Evaluator = &eval.FileTypeEvaluator{
+		r.Evaluator = &eval.JSONEvaluator{
 			Logger: log.WithFields(log.Fields{
 				"evaluator": "json",
 				"component": "evaluator",
 			}),
 		}
-	case "yaml":
-		r.Evaluator = &eval.FileTypeEvaluator{
-			Logger: log.WithFields(log.Fields{
-				"evaluator": "yaml",
-				"component": "evaluator",
-			}),
-		}
 	default:
 		return errors.New("no evaluator set")
 	}
@@ -84,6 +77,8 @@ func (r *Runtime) setSyncImplFromConfig() error {
 					"component": "sync",
 				}),
 				ProviderArgs: r.config.ProviderArgs,
+				// evaluator here is file type: `json`, `yaml` etc.,
+				FileType: r.config.Evaluator,
 			})
 			log.Debugf("Using %s sync-provider on %q\n", r.config.SyncProvider, u)
 		}

pkg/sync/filepath_sync.go

@@ -2,10 +2,14 @@ package sync
 
 import (
 	"context"
+	"encoding/json"
 	"errors"
+	"fmt"
 	"os"
 
+	"github.com/open-feature/flagd/pkg/eval"
 	log "github.com/sirupsen/logrus"
+	"gopkg.in/yaml.v2"
 
 	"github.com/fsnotify/fsnotify"
 )
@@ -14,6 +18,9 @@ type FilePathSync struct {
 	URI          string
 	Logger       *log.Entry
 	ProviderArgs ProviderArgs
+	// FileType indicates the file type e.g., json, yaml etc.,
+	// TODO: limit this to `json` or `yaml only?`
+	FileType string
 }
 
 func (fs *FilePathSync) Source() string {
@@ -28,7 +35,21 @@ func (fs *FilePathSync) Fetch(_ context.Context) (string, error) {
 	if err != nil {
 		return "", err
 	}
-	return string(rawFile), nil
+
+	var config eval.FlagsAndEvaluators
+	err = yaml.Unmarshal(rawFile, &config)
+	if err != nil {
+		return "", fmt.Errorf("unmarshal yaml: %w", err)
+	}
+
+	fmt.Println("config", config)
+
+	r, err := json.Marshal(config)
+	if err != nil {
+		return "", fmt.Errorf("marshal json: %w", err)
+	}
+
+	return string(r), nil
 }
 
 func (fs *FilePathSync) Notify(ctx context.Context, w chan<- INotify) {