[FFM-10027] - Fall back to identifier if bucketBy attribute is not found (#136)

* [FFM-10027] - Fall back to identifier if bucketBy attribute is not found

What
Update BucketBy logic to fall back to the target identifier if given BucketBy attribute is not found.

Why
Keep the SDK consistent with the behaviour of the other server SDKs.

Testing
Testgrid + manual

Author: andybharness

analyticsservice/analytics.go

@@ -25,7 +25,7 @@ const (
 	variationValueAttribute      string = "featureValue"
 	targetAttribute              string = "target"
 	sdkVersionAttribute          string = "SDK_VERSION"
-	SdkVersion                   string = "0.1.16"
+	SdkVersion                   string = "0.1.17"
 	sdkTypeAttribute             string = "SDK_TYPE"
 	sdkType                      string = "server"
 	sdkLanguageAttribute         string = "SDK_LANGUAGE"

evaluation/util.go

@@ -2,6 +2,7 @@ package evaluation
 
 import (
 	"fmt"
+	"github.com/harness/ff-golang-server-sdk/sdk_codes"
 	"reflect"
 	"strconv"
 	"strings"
@@ -33,6 +34,8 @@ func getAttrValue(target *Target, attr string) reflect.Value {
 			value = reflect.ValueOf(target.Identifier)
 		case "name":
 			value = reflect.ValueOf(target.Name)
+		default:
+			value = reflect.ValueOf("")
 		}
 	}
 	return value
@@ -70,6 +73,7 @@ func findVariation(variations []rest.Variation, identifier string) (rest.Variati
 
 func getNormalizedNumber(identifier, bucketBy string) int {
 	value := []byte(strings.Join([]string{bucketBy, identifier}, ":"))
+	log.Debugf("MM3 input [%s]", string(value))
 	hasher := murmur3.New32()
 	_, err := hasher.Write(value)
 	if err != nil {
@@ -83,10 +87,18 @@ func isEnabled(target *Target, bucketBy string, percentage int) bool {
 	value := getAttrValue(target, bucketBy)
 	identifier := value.String()
 	if identifier == "" {
-		return false
+		var oldBB = bucketBy
+		bucketBy = "identifier"
+		value = getAttrValue(target, bucketBy)
+		identifier = value.String()
+		if identifier == "" {
+			return false
+		}
+		log.Warnf("%s BucketBy attribute not found in target attributes, falling back to 'identifier': missing=%s, using value=%s", sdk_codes.MissingBucketBy, oldBB, identifier)
 	}
 
 	bucketID := getNormalizedNumber(identifier, bucketBy)
+	log.Debugf("MM3 percentage_check=%d bucket_by=%s value=%s bucket=%d", percentage, bucketBy, identifier, bucketID)
 	return percentage > 0 && bucketID <= percentage
 }
 

evaluation/util_test.go

@@ -26,7 +26,7 @@ func Test_getAttrValueIsNil(t *testing.T) {
 			want: reflect.Value{},
 		},
 		{
-			name: "wrong attribute should return Value{}",
+			name: "wrong attribute should return ValueOf('')",
 			args: args{
 				target: &Target{
 					Identifier: harness,
@@ -36,7 +36,7 @@ func Test_getAttrValueIsNil(t *testing.T) {
 				},
 				attr: "no_identifier",
 			},
-			want: reflect.Value{},
+			want: reflect.ValueOf(""),
 		},
 	}
 	for _, tt := range tests {

sdk_codes/sdk_codes.go

@@ -24,6 +24,7 @@ const (
 	StreamStop         SDKCode = "SDKCODE:5004"
 	EvaluationSuccess  SDKCode = "SDKCODE:6000"
 	EvaluationFailed   SDKCode = "SDKCODE:6001"
+	MissingBucketBy    SDKCode = "SDKCODE:6002"
 	MetricsStarted     SDKCode = "SDKCODE:7000"
 	MetricsStopped     SDKCode = "SDKCODE:7001"
 	MetricsSendFail    SDKCode = "SDKCODE:7002"