pr feedback

discovery/client.go

@@ -95,7 +95,7 @@ func (r *clientRegistrationManager) activate(ctx context.Context, serviceID, sub
 	subjectDIDs = subjectDIDs[:j]
 
 	if len(subjectDIDs) == 0 {
-		return fmt.Errorf("%w: %w for %s", ErrPresentationRegistrationFailed, ErrDIDMethodsNotSupported, subjectID)
+		return fmt.Errorf("%w: %w for %s", ErrPresentationRegistrationFailed, ErrNoSupportedDIDMethods, subjectID)
 	}
 
 	log.Logger().Debugf("Registering Verifiable Presentation on Discovery Service (service=%s, subject=%s)", service.ID, subjectID)
@@ -167,7 +167,7 @@ func (r *clientRegistrationManager) deactivate(ctx context.Context, serviceID, s
 	}
 	if len(subjectDIDs) == 0 {
 		// if this means we can't deactivate a previously registered subject because the DID methods have changed, then we rely on the refresh interval to clean up.
-		return fmt.Errorf("%w: %w for %s", ErrPresentationRegistrationFailed, ErrDIDMethodsNotSupported, subjectID)
+		return fmt.Errorf("%w: %w for %s", ErrPresentationRegistrationFailed, ErrNoSupportedDIDMethods, subjectID)
 	}
 
 	// find all active presentations
@@ -287,7 +287,7 @@ func (r *clientRegistrationManager) refresh(ctx context.Context, now time.Time)
 	for _, candidate := range refreshCandidates {
 		var loopErr error
 		if err = r.activate(ctx, candidate.ServiceID, candidate.SubjectID, candidate.Parameters); err != nil {
-			if errors.Is(err, ErrDIDMethodsNotSupported) {
+			if errors.Is(err, ErrNoSupportedDIDMethods) {
 				// DID method no longer supported, remove
 				err = r.store.updatePresentationRefreshTime(candidate.ServiceID, candidate.SubjectID, nil, nil)
 				if err != nil {

discovery/client_test.go

@@ -131,7 +131,7 @@ func Test_defaultClientRegistrationManager_activate(t *testing.T) {
 
 		err := ctx.manager.activate(audit.TestContext(), unsupportedServiceID, aliceSubject, defaultRegistrationParams(aliceSubject))
 
-		assert.ErrorIs(t, err, ErrDIDMethodsNotSupported)
+		assert.ErrorIs(t, err, ErrNoSupportedDIDMethods)
 	})
 	t.Run("no matching credentials", func(t *testing.T) {
 		ctx := newTestContext(t)
@@ -255,7 +255,7 @@ func Test_defaultClientRegistrationManager_deactivate(t *testing.T) {
 
 		err := ctx.manager.deactivate(audit.TestContext(), unsupportedServiceID, aliceSubject)
 
-		assert.ErrorIs(t, err, ErrDIDMethodsNotSupported)
+		assert.ErrorIs(t, err, ErrNoSupportedDIDMethods)
 	})
 	t.Run("deregistering from Discovery Service fails", func(t *testing.T) {
 		ctx := newTestContext(t)

discovery/interface.go

@@ -34,8 +34,12 @@ var ErrPresentationAlreadyExists = errors.New("presentation already exists")
 // ErrPresentationRegistrationFailed indicates registration of a presentation on a remote Discovery Service failed.
 var ErrPresentationRegistrationFailed = errors.New("registration of Verifiable Presentation on remote Discovery Service failed")
 
+// ErrDIDMethodsNotSupported indicates that a received VP does not match the supported DID Methods of the service.
 var ErrDIDMethodsNotSupported = errors.New("DID methods not supported")
 
+// ErrNoSupportedDIDMethods indicates that the client cannot create a VP for a subject because it has no (active) DID matching the supported DID Methods of the service.
+var ErrNoSupportedDIDMethods = errors.New("subject has no (active) DIDs matching the service")
+
 // authServerURLField is the field name for the authServerURL in the DiscoveryRegistrationCredential.
 // it is used to resolve authorization server metadata and thus the endpoints for a service entry.
 const authServerURLField = "authServerURL"

discovery/module_test.go

@@ -633,7 +633,7 @@ func TestModule_ActivateServiceForSubject(t *testing.T) {
 
 		err := m.ActivateServiceForSubject(context.Background(), testServiceID, aliceSubject, nil)
 
-		assert.ErrorIs(t, err, ErrDIDMethodsNotSupported)
+		assert.ErrorIs(t, err, ErrNoSupportedDIDMethods)
 	})
 	t.Run("ok, but couldn't register presentation -> maps to ErrRegistrationFailed", func(t *testing.T) {
 		storageEngine := storage.NewTestStorageEngine(t)