Addressing comments

internal/brokers/broker.go

@@ -96,7 +96,10 @@ func (b Broker) newSession(ctx context.Context, username, lang string) (sessionI
 func (b Broker) GetAuthenticationModes(ctx context.Context, sessionID string, supportedUILayouts []map[string]string) (authenticationModes []map[string]string, err error) {
 	sessionID = b.parseSessionID(sessionID)
 
-	b.generateValidators(supportedUILayouts)
+	b.layoutValidators, err = generateValidators(supportedUILayouts)
+	if err != nil {
+		return nil, fmt.Errorf("could not generate layout validators: %w", err)
+	}
 
 	authenticationModes, err = b.brokerer.GetAuthenticationModes(ctx, sessionID, supportedUILayouts)
 	if err != nil {
@@ -188,19 +191,23 @@ func (b Broker) cancelIsAuthorized(ctx context.Context, sessionID string) {
 //	        }
 //	    }
 //	}
-func (b *Broker) generateValidators(supportedUILayouts []map[string]string) {
+func generateValidators(supportedUILayouts []map[string]string) (map[string]map[string]fieldValidator, error) {
 	validators := make(map[string]map[string]fieldValidator)
 	for _, layout := range supportedUILayouts {
+		if _, exists := layout["type"]; !exists {
+			return nil, fmt.Errorf("Supported UI layouts are invalid")
+		}
+
 		layoutValidator := make(map[string]fieldValidator)
 		for key, value := range layout {
 			if key == "type" {
 				continue
 			}
 
-			modifier, supportedValues, _ := strings.Cut(value, ":")
+			required, supportedValues, _ := strings.Cut(value, ":")
 			validator := fieldValidator{
 				supportedValues: nil,
-				required:        (modifier == "required"),
+				required:        (required == "required"),
 			}
 			if supportedValues != "" {
 				validator.supportedValues = strings.Split(supportedValues, ",")
@@ -209,7 +216,7 @@ func (b *Broker) generateValidators(supportedUILayouts []map[string]string) {
 		}
 		validators[layout["type"]] = layoutValidator
 	}
-	b.layoutValidators = validators
+	return validators, nil
 }
 
 // validateUILayout validates the layout fields and content according to the broker validators and returns the layout

internal/brokers/broker_test.go

@@ -165,7 +165,10 @@ func TestSelectAuthenticationMode(t *testing.T) {
 			t.Parallel()
 
 			b, _ := newBrokerForTests(t)
-			b.GenerateLayoutValidators(supportedLayouts)
+
+			// This is normally done in the broker's GetAuthenticationModes method, but we need to do it here to test the SelectAuthenticationMode method.
+			err := brokers.GenerateLayoutValidators(&b, supportedLayouts)
+			require.NoError(t, err, "Setup: could not generate layout validators")
 
 			gotUI, err := b.SelectAuthenticationMode(context.Background(), tc.sessionID, "mode1")
 			if tc.wantErr {

internal/brokers/export_test.go

@@ -27,7 +27,11 @@ func (m *Manager) SetBrokerForSession(b *Broker, sessionID string) {
 	m.transactionsToBrokerMu.Unlock()
 }
 
-// GenerateLayoutValidators exports the private generateValidators function for testing purposes.
-func (b *Broker) GenerateLayoutValidators(supportedUILayouts []map[string]string) {
-	b.generateValidators(supportedUILayouts)
+// GenerateLayoutValidators generates the layout validators and assign them to the specified broker.
+func GenerateLayoutValidators(b *Broker, supportedUILayouts []map[string]string) (err error) {
+	b.layoutValidators, err = generateValidators(supportedUILayouts)
+	if err != nil {
+		return err
+	}
+	return nil
 }