Oversight in fde9694

Author: cdoublev

lib/error.js

@@ -27,6 +27,9 @@ export const INVALID_CUSTOM_PROPERTY_OVERRIDE = {
 export const INVALID_CUSTOM_PROPERTY_SYNTAX = {
     message: 'Invalid syntax',
 }
+export const INVALID_DECLARATION_SYNTAX_ERROR = {
+    message: 'Cannot parse invalid declaration',
+}
 export const INVALID_DECLARATION_VALUE_ERROR = {
     message: 'Cannot parse invalid declaration value',
 }

lib/serialize.js

@@ -1703,6 +1703,8 @@ function serializeComponentValue(value, context) {
                 return serializeFeatureTagValue(value)
             case '<function>':
                 return serializeFunction(value)
+            case '<function-token>':
+                return `${serializeIdentifier(value)}(`
             case '<hash-token>':
                 return serializeHash(value)
             case '<image-set-option>':