Refactor Policy Enforcer to Policy Checker

- Renamed the `PolicyEnforcer` interface and related implementations to `PolicyChecker` for clarity and consistency.
- Updated configuration keys in YAML files to reflect the new `checkPolicy` terminology.
- Adjusted related code, tests, and documentation to support the new naming convention and ensure compatibility.
- Enhanced comments and examples for the `checkPolicy` configuration to improve usability.

core/module/handler/config.go

@@ -19,7 +19,7 @@ type PluginManager interface {
 	Publisher(ctx context.Context, cfg *plugin.Config) (definition.Publisher, error)
 	Signer(ctx context.Context, cfg *plugin.Config) (definition.Signer, error)
 	Step(ctx context.Context, cfg *plugin.Config) (definition.Step, error)
-	PolicyEnforcer(ctx context.Context, cfg *plugin.Config) (definition.PolicyEnforcer, error)
+	PolicyChecker(ctx context.Context, cfg *plugin.Config) (definition.PolicyChecker, error)
 	Cache(ctx context.Context, cfg *plugin.Config) (definition.Cache, error)
 	Registry(ctx context.Context, cfg *plugin.Config) (definition.RegistryLookup, error)
 	KeyManager(ctx context.Context, cache definition.Cache, rLookup definition.RegistryLookup, cfg *plugin.Config) (definition.KeyManager, error)
@@ -38,7 +38,7 @@ const (
 // PluginCfg holds the configuration for various plugins.
 type PluginCfg struct {
 	SchemaValidator  *plugin.Config  `yaml:"schemaValidator,omitempty"`
-	PolicyEnforcer   *plugin.Config  `yaml:"policyEnforcer,omitempty"`
+	PolicyChecker    *plugin.Config  `yaml:"checkPolicy,omitempty"`
 	SignValidator    *plugin.Config  `yaml:"signValidator,omitempty"`
 	Publisher        *plugin.Config  `yaml:"publisher,omitempty"`
 	Signer           *plugin.Config  `yaml:"signer,omitempty"`

core/module/handler/stdHandler.go

@@ -35,7 +35,7 @@ type stdHandler struct {
 	registry         definition.RegistryLookup
 	km               definition.KeyManager
 	schemaValidator  definition.SchemaValidator
-	policyEnforcer   definition.PolicyEnforcer
+	policyChecker    definition.PolicyChecker
 	router           definition.Router
 	publisher        definition.Publisher
 	transportWrapper definition.TransportWrapper
@@ -319,7 +319,7 @@ func (h *stdHandler) initPlugins(ctx context.Context, mgr PluginManager, cfg *Pl
 	if h.transportWrapper, err = loadPlugin(ctx, "TransportWrapper", cfg.TransportWrapper, mgr.TransportWrapper); err != nil {
 		return err
 	}
-	if h.policyEnforcer, err = loadPlugin(ctx, "PolicyEnforcer", cfg.PolicyEnforcer, mgr.PolicyEnforcer); err != nil {
+	if h.policyChecker, err = loadPlugin(ctx, "PolicyChecker", cfg.PolicyChecker, mgr.PolicyChecker); err != nil {
 		return err
 	}
 
@@ -354,8 +354,8 @@ func (h *stdHandler) initSteps(ctx context.Context, mgr PluginManager, cfg *Conf
 			s, err = newValidateSchemaStep(h.schemaValidator)
 		case "addRoute":
 			s, err = newAddRouteStep(h.router)
-		case "policyEnforcer":
-			s, err = newEnforcePolicyStep(h.policyEnforcer)
+		case "checkPolicy":
+			s, err = newCheckPolicyStep(h.policyChecker)
 		default:
 			if customStep, exists := steps[step]; exists {
 				s = customStep

core/module/handler/stdHandler_test.go

@@ -1,11 +1,69 @@
 package handler
 
 import (
+	"context"
 	"net/http"
+	"strings"
 	"testing"
 	"time"
+
+	"github.com/beckn-one/beckn-onix/pkg/plugin"
+	"github.com/beckn-one/beckn-onix/pkg/plugin/definition"
 )
 
+// noopPluginManager satisfies PluginManager with nil plugins (unused loaders are never invoked when config is omitted).
+type noopPluginManager struct{}
+
+func (noopPluginManager) Middleware(context.Context, *plugin.Config) (func(http.Handler) http.Handler, error) {
+	return nil, nil
+}
+func (noopPluginManager) SignValidator(context.Context, *plugin.Config) (definition.SignValidator, error) {
+	return nil, nil
+}
+func (noopPluginManager) Validator(context.Context, *plugin.Config) (definition.SchemaValidator, error) {
+	return nil, nil
+}
+func (noopPluginManager) Router(context.Context, *plugin.Config) (definition.Router, error) { return nil, nil }
+func (noopPluginManager) Publisher(context.Context, *plugin.Config) (definition.Publisher, error) {
+	return nil, nil
+}
+func (noopPluginManager) Signer(context.Context, *plugin.Config) (definition.Signer, error) { return nil, nil }
+func (noopPluginManager) Step(context.Context, *plugin.Config) (definition.Step, error) { return nil, nil }
+func (noopPluginManager) PolicyChecker(context.Context, *plugin.Config) (definition.PolicyChecker, error) {
+	return nil, nil
+}
+func (noopPluginManager) Cache(context.Context, *plugin.Config) (definition.Cache, error) { return nil, nil }
+func (noopPluginManager) Registry(context.Context, *plugin.Config) (definition.RegistryLookup, error) {
+	return nil, nil
+}
+func (noopPluginManager) KeyManager(context.Context, definition.Cache, definition.RegistryLookup, *plugin.Config) (definition.KeyManager, error) {
+	return nil, nil
+}
+func (noopPluginManager) TransportWrapper(context.Context, *plugin.Config) (definition.TransportWrapper, error) {
+	return nil, nil
+}
+func (noopPluginManager) SchemaValidator(context.Context, *plugin.Config) (definition.SchemaValidator, error) {
+	return nil, nil
+}
+
+func TestNewStdHandler_CheckPolicyStepWithoutPluginFails(t *testing.T) {
+	ctx := context.Background()
+	cfg := &Config{
+		Plugins: PluginCfg{},
+		Steps:   []string{"checkPolicy"},
+	}
+	_, err := NewStdHandler(ctx, noopPluginManager{}, cfg, "testModule")
+	if err == nil {
+		t.Fatal("expected error when steps list checkPolicy but checkPolicy plugin is omitted")
+	}
+	if !strings.Contains(err.Error(), "failed to initialize steps") {
+		t.Fatalf("expected steps init failure, got: %v", err)
+	}
+	if !strings.Contains(err.Error(), "PolicyChecker plugin not configured") {
+		t.Fatalf("expected explicit PolicyChecker config error, got: %v", err)
+	}
+}
+
 func TestNewHTTPClient(t *testing.T) {
 	tests := []struct {
 		name     string

core/module/handler/step.go

@@ -316,10 +316,18 @@ func extractSchemaVersion(body []byte) string {
 	return "unknown"
 }
 
-// newEnforcePolicyStep creates and returns the enforcePolicy step after validation.
-func newEnforcePolicyStep(policyEnforcer definition.PolicyEnforcer) (definition.Step, error) {
-	if policyEnforcer == nil {
-		return nil, fmt.Errorf("invalid config: PolicyEnforcer plugin not configured")
-	}
-	return policyEnforcer, nil
+// checkPolicyStep adapts PolicyChecker into the Step interface.
+type checkPolicyStep struct {
+	checker definition.PolicyChecker
+}
+
+func newCheckPolicyStep(policyChecker definition.PolicyChecker) (definition.Step, error) {
+	if policyChecker == nil {
+		return nil, fmt.Errorf("invalid config: PolicyChecker plugin not configured")
+	}
+	return &checkPolicyStep{checker: policyChecker}, nil
+}
+
+func (s *checkPolicyStep) Run(ctx *model.StepContext) error {
+	return s.checker.CheckPolicy(ctx)
 }

core/module/module_test.go

@@ -79,8 +79,8 @@ func (m *mockPluginManager) SchemaValidator(ctx context.Context, cfg *plugin.Con
 	return nil, nil
 }
 
-// PolicyEnforcer returns a mock policy enforcer implementation.
-func (m *mockPluginManager) PolicyEnforcer(ctx context.Context, cfg *plugin.Config) (definition.PolicyEnforcer, error) {
+// PolicyChecker returns a mock policy checker implementation.
+func (m *mockPluginManager) PolicyChecker(ctx context.Context, cfg *plugin.Config) (definition.PolicyChecker, error) {
 	return nil, nil
 }