December 2018 (version 1.20.0)

1.20.0 Update


This was quite a year. We like to appreciate everyone who has visited and used us these far.

Wishing you a happy and exciting new year! Thank you.

We will keep up the hard work as to provide top notch services for JavaScript.

Please kindly go ahead with the highlights for the latest release.

Release Summary

This version includes a number of updates that we hope you've found some of them helpful.
The key highlights are:

New Rules

New rules introduced in this release:

  • USELESS_CATCH - Do not just rethrow the caught exception in the catch clause

Improved Rules

The following rules have been improved:

Extended Language Support

We have added support for useful language features currently in ESNext and Flow.

  • Support private instance methods and private static fields
  • Support Flow inexact object type syntax


  • Support for React v16.6 like memo() and lazy()
  • Disallow using _ as Flow type identifier because it is reserved for implicit instantiation (SYNTAX_ERROR)

Bug Fixes