Make filepath optional in riotconfig.

Readme.md

@@ -5,8 +5,6 @@
 
 The Riot.js official parcel transformer.
 
-🚧 Parcel 2 was just released and this package is still under development and not yet 100% ready. Come back soon
-
 ## Important
 
 - If you are using Parcel < 2.0.0 please check the [this branch](https://github.com/riot/parcel-transformer-riot/tree/parcel-v1)

index.js

@@ -33,8 +33,8 @@ module.exports = new Transformer({
       }
     )
     const shouldInvalidateOnStartup = riotConfig &&
-      riotConfig.filePath.endsWith('.js') ||
+      riotConfig?.filePath?.endsWith('.js') ||
-      riotConfig.filePath.endsWith(CONFIG_FILES[0])
+      riotConfig?.filePath?.endsWith(CONFIG_FILES[0])
 
     if (shouldInvalidateOnStartup) {
       config.invalidateOnStartup()