【RAILS】エラー対応記録-herokuデプロイ時「Uglifier::Error: Unexpected token name «of», expected punc «;». To use ES6 syntax,…」 - Qiita

【RAILS】エラー対応記録-herokuデプロイ時「Uglifier::Error: Unexpected token name «of», expected punc «;». To use ES6 syntax,…」Rails $ git push memo-space master Enumerating objects: 139, done. Counting objects: 100% (139/139), done. Delta compression using up to 16 threads Compressing objects: 100% (107/107), done. Writing objects: 100% (113/113), 15.19 KiB | 3.80 MiB/s, done. Total 113 (delta 71), reused 0 (del