[firestore-translate-text] fix bug that didn't allow single language list (#46)

Author: thatfiredev

firestore-translate-text/extension.yaml

@@ -90,7 +90,7 @@ params:
       For these codes, visit the [supported languages list](https://cloud.google.com/translate/docs/languages).
     default: en,es,de,fr
     example: en,es,de,fr
-    validationRegex: "^[a-zA-Z,-]+[a-zA-Z-]{2,}$"
+    validationRegex: "^[a-zA-Z,-]*[a-zA-Z-]{2,}$"
     validationErrorMessage:
       Languages must be a comma-separated list of ISO-639-1 language codes.
     required: true

firestore-translate-text/functions/src/config.ts

@@ -15,7 +15,9 @@
  */
 
 export default {
-  languages: process.env.LANGUAGES.split(","),
+  languages: Array.from(
+    new Set(process.env.LANGUAGES.split(","))
+  ),
   location: process.env.LOCATION,
   inputFieldName: process.env.INPUT_FIELD_NAME,
   outputFieldName: process.env.OUTPUT_FIELD_NAME,