feat: add sem_ver jsonLogic evaluator

core/go.mod

@@ -31,6 +31,7 @@ require (
 	go.opentelemetry.io/otel/trace v1.16.0
 	go.uber.org/zap v1.24.0
 	golang.org/x/crypto v0.8.0
+	golang.org/x/mod v0.9.0
 	golang.org/x/net v0.10.0
 	golang.org/x/sync v0.2.0
 	google.golang.org/grpc v1.55.0

core/go.sum

@@ -693,8 +693,6 @@ github.com/stretchr/testify v1.7.0/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/
 github.com/stretchr/testify v1.7.1/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
 github.com/stretchr/testify v1.8.0/go.mod h1:yNjHg4UonilssWZ8iaSj1OCr/vHnekPRkoO+kdMU+MU=
 github.com/stretchr/testify v1.8.1/go.mod h1:w2LPCIKwWwSfY2zedu0+kehJoqGctiVI29o6fzry7u4=
-github.com/stretchr/testify v1.8.2 h1:+h33VjcLVPDHtOdpUCuF+7gSuG3yGIftsP1YvFihtJ8=
-github.com/stretchr/testify v1.8.2/go.mod h1:w2LPCIKwWwSfY2zedu0+kehJoqGctiVI29o6fzry7u4=
 github.com/stretchr/testify v1.8.3 h1:RP3t2pwF7cMEbC1dqtB6poj3niw/9gnV4Cjg5oW5gtY=
 github.com/stretchr/testify v1.8.3/go.mod h1:sz/lmYIOXD/1dqDmKjjqLyZ2RngseejIcXlSw2iwfAo=
 github.com/stretchr/testify v1.8.4 h1:CcVxjf3Q8PM0mHUKJCdn+eZZtm5yQwehR5yeSVQQcUk=
@@ -815,6 +813,8 @@ golang.org/x/mod v0.4.2/go.mod h1:s0Qsj1ACt9ePp/hMypM3fl4fZqREWJwdYDEqhRiZZUA=
 golang.org/x/mod v0.5.0/go.mod h1:5OXOZSfqPIIbmVBIIKWRFfZjPR0E5r58TLhUjH0a2Ro=
 golang.org/x/mod v0.6.0-dev.0.20220419223038-86c51ed26bb4/go.mod h1:jJ57K6gSWd91VN4djpZkiMVwK6gcyfeH4XE8wZrZaV4=
 golang.org/x/mod v0.7.0/go.mod h1:iBbtSCu2XBx23ZKBPSOrRkjjQPZFPuis4dIYUhu/chs=
+golang.org/x/mod v0.9.0 h1:KENHtAZL2y3NLMYZeHY9DW8HW8V+kQyJsY/V9JlKvCs=
+golang.org/x/mod v0.9.0/go.mod h1:iBbtSCu2XBx23ZKBPSOrRkjjQPZFPuis4dIYUhu/chs=
 golang.org/x/net v0.0.0-20180724234803-3673e40ba225/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
 golang.org/x/net v0.0.0-20180826012351-8a410e7b638d/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
 golang.org/x/net v0.0.0-20190108225652-1e06a53dbb7e/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=

core/pkg/eval/json_evaluator.go

@@ -65,6 +65,10 @@ func NewJSONEvaluator(logger *logger.Logger, s *store.Flags) *JSONEvaluator {
 	}
 	jsonlogic.AddOperator("starts_with", sce.StartsWithEvaluation)
 	jsonlogic.AddOperator("ends_with", sce.EndsWithEvaluation)
+
+	sve := SemVerComparisonEvaluator{Logger: ev.Logger}
+	jsonlogic.AddOperator("sem_ver", sve.SemVerEvaluation)
+
 	return &ev
 }
 

core/pkg/eval/semver_evaluation.go

@@ -0,0 +1,144 @@
+package eval
+
+import (
+	"errors"
+	"fmt"
+	"strings"
+
+	"github.com/open-feature/flagd/core/pkg/logger"
+	"golang.org/x/mod/semver"
+)
+
+type SemVerOperator string
+
+const (
+	Equals         SemVerOperator = "="
+	NotEqual       SemVerOperator = "!="
+	Less           SemVerOperator = "<"
+	LessOrEqual    SemVerOperator = "<="
+	GreaterOrEqual SemVerOperator = ">="
+	Greater        SemVerOperator = ">"
+	MatchMajor     SemVerOperator = "^"
+	MatchMinor     SemVerOperator = "~"
+)
+
+func (svo SemVerOperator) compare(v1, v2 string) (bool, error) {
+	cmpRes := semver.Compare(v1, v2)
+	switch svo {
+	case Less:
+		return cmpRes == -1, nil
+	case Equals:
+		return cmpRes == 0, nil
+	case NotEqual:
+		return cmpRes != 0, nil
+	case LessOrEqual:
+		return cmpRes == -1 || cmpRes == 0, nil
+	case GreaterOrEqual:
+		return cmpRes == +1 || cmpRes == 0, nil
+	case Greater:
+		return cmpRes == +1, nil
+	case MatchMinor:
+		v1MajorMinor := semver.MajorMinor(v1)
+		v2MajorMinor := semver.MajorMinor(v2)
+		return semver.Compare(v1MajorMinor, v2MajorMinor) == 0, nil
+	case MatchMajor:
+		v1Major := semver.Major(v1)
+		v2Major := semver.Major(v2)
+		return semver.Compare(v1Major, v2Major) == 0, nil
+	default:
+		return false, errors.New("invalid operator")
+	}
+}
+
+type SemVerComparisonEvaluator struct {
+	Logger *logger.Logger
+}
+
+// SemVerEvaluation checks if the given property matches a semantic versioning condition.
+// It returns 'true', if the value of the given property meets the condition, 'false' if not.
+// As an example, it can be used in the following way inside an 'if' evaluation:
+//
+//	{
+//	  "if": [
+//			{
+//				"sem_ver": [{"var": "version"}, ">=", "1.0.0"]
+//			},
+//			"red", null
+//			]
+//	}
+//
+// This rule can be applied to the following data object, where the evaluation will resolve to 'true':
+//
+// { "version": "2.0.0" }
+//
+// Note that the 'sem_ver' evaluation rule must contain exactly three items:
+// 1. Target property: this needs which both resolve to a semantic versioning string
+// 2. Operator: One of the following: '=', '!=', '>', '<', '>=', '<=', '~', '^'
+// 3. Target value: this needs which both resolve to a semantic versioning string
+func (je *SemVerComparisonEvaluator) SemVerEvaluation(values, _ interface{}) interface{} {
+	actualVersion, targetVersion, operator, err := parseSemverEvaluationData(values)
+	if err != nil {
+		je.Logger.Error(fmt.Sprintf("parse sem_ver evaluation data: %v", err))
+		return nil
+	}
+	res, err := operator.compare(actualVersion, targetVersion)
+	if err != nil {
+		je.Logger.Error(fmt.Sprintf("sem_ver evaluation: %v", err))
+		return nil
+	}
+	return res
+}
+
+func parseSemverEvaluationData(values interface{}) (string, string, SemVerOperator, error) {
+	parsed, ok := values.([]interface{})
+	if !ok {
+		return "", "", "", errors.New("sem_ver evaluation is not an array")
+	}
+
+	if len(parsed) != 3 {
+		return "", "", "", errors.New("sem_ver evaluation must contain a value, an operator and a comparison target")
+	}
+
+	actualVersion, err := parseSemanticVersion(parsed[0])
+	if err != nil {
+		return "", "", "", fmt.Errorf("sem_ver evaluation: could not parse target property value: %w", err)
+	}
+
+	operator, err := parseOperator(parsed[1])
+	if err != nil {
+		return "", "", "", fmt.Errorf("sem_ver evaluation: could not parse operator: %w", err)
+	}
+
+	targetVersion, err := parseSemanticVersion(parsed[2])
+	if err != nil {
+		return "", "", "", fmt.Errorf("sem_ver evaluation: could not parse target value: %w", err)
+	}
+	return actualVersion, targetVersion, operator, nil
+}
+
+func parseSemanticVersion(v interface{}) (string, error) {
+	version, ok := v.(string)
+	if !ok {
+		return "", errors.New("sem_ver evaluation: property did not resolve to a string value")
+	}
+	// version strings are only valid in the semver package if they start with a 'v'
+	// if it's not present in the given value, we prepend it
+	if !strings.HasPrefix(version, "v") {
+		version = "v" + version
+	}
+
+	if !semver.IsValid(version) {
+		return "", errors.New("not a valid semantic version string")
+	}
+
+	return version, nil
+}
+
+func parseOperator(o interface{}) (SemVerOperator, error) {
+	operatorString, ok := o.(string)
+	if !ok {
+		return "", errors.New("could not parse operator")
+	}
+
+	return SemVerOperator(operatorString), nil
+}