Start your boolean name with an auxiliary verb.
Callbacks are disgusting flies in the delicious ES6 soup. Refactor them to use promises only.
I wrote a decorator to solve the concurrency problem of promises and published to npm. Waiting for you to take a look and try!
When your browser extension or any other front end app needs to add a regular expression field, your back end teammate gave you api response like this...
Think about boolean algebra when you are struggling with writing if statements.