ESLint v4.0.0 released

Highlights

• There are several breaking changes in 4.0.0. We’ve created a migration guide to explain the breaking changes and describe how to upgrade.
• Seven new rules have been added:
  • array-element-newline
  • semi-style
  • padding-line-between-statements
  • for-direction
  • switch-colon-spacing
  • array-bracket-newline
  • no-buffer-constructor
• Two rules are now autofixable with the --fix flag:
  • no-debugger
  • no-confusing-arrow
• Three rules have been deprecated in favor of the new padding-line-between-statements rule:
  • lines-around-directive
  • newline-after-var
  • newline-before-return
• Three new utility methods have been added to the SourceCode API, and SourceCode#getComments has been deprecated.
• A new option has been added to the object-curly-newline rule.

Changes since v4.0.0-rc.0:

Enhancements

• 34c4020 Update: Add support for parens on left side for-loops (fixes: #8393) (#8679) (Victor Hom)

Bug Fixes

• 3da7b5e Fix: Semi-Style only check for comments when tokens exist (fixes #8696) (#8697) (Reyad Attiyat)
• 3cfe9ee Fix: Add space between async and param on fix (fixes #8682) (#8693) (Reyad Attiyat)

Documentation

• 735cd09 Docs: Correct the comment in an example for no-mixed-requires (#8686) (Fangzhou Li)

Chores

• 4aefb49 Chore: avoid using deprecated rules on ESLint codebase (#8708) (Teddy Katz)
• 389feba Chore: upgrade deps. (#8684) (薛定谔的猫)
• c702858 Chore: enable no-multiple-empty-lines on ESLint codebase (#8694) (Teddy Katz)
• 026f048 Chore: remove dead code from prefer-const (#8683) (Teddy Katz)