Note: This version of ESLint is not ready for production use and is provided to gather feedback from the community before releasing the final version. Please let us know if you having any problems or feedback by creating issues on our GitHub repo or joining our Gitter channel.
Highlights
This is a summary of the major changes you need to know about for this version of ESLint.
Installing
Since this is a pre-release version, you will not automatically be upgraded by npm. You must specify the next tag when installing:
npm i eslint@next --save-dev
You can also specify the version directly:
npm i eslint@4.0.0-alpha.0 --save-dev
Migration Guide
As there are a lot of changes, we’ve created a migration guide describing the changes in great detail along with the steps you should take to address them. Not all ESLint users will be affected by the changes, however, the changes are big enough that we recommend everyone read the migration thoroughly.
New Rules
There is one new rule in this release:
Breaking Changes
- f5a7e42 Breaking: log number of fixable problems (fixes #7364) (#8324) (alberto)
- cc53481 Breaking: rewrite indent (fixes #1801, #3737, #3845, #6007, …16 more) (#7618) (Teddy Katz)
- 867dd2e Breaking: Calculate leading/trailing comments in core (fixes #6724) (#7516) (Kai Cataldo)
- 66af53e Breaking: Traverse into type annotations (fixes #7129) (#8365) (Kai Cataldo)
- e395919 Breaking: Resolve patterns from .eslintignore directory (fixes #6759) (#7678) (Ian VanSchooten)
- c778676 Breaking: convert RuleTester to ES6 class (refs #8231) (#8263) (Teddy Katz)
- 6f7757e Breaking: convert SourceCode to ES6 class (refs #8231) (#8264) (Teddy Katz)
- 9a9d916 Breaking: update eslint:recommended for 4.0.0 (fixes #8236) (#8372) (Teddy Katz)
- b0c63f0 Breaking: infer endLine and endColumn from a reported node (fixes #8004) (#8234) (Teddy Katz)
- 40b8c69 Breaking: no-multi-spaces check around inline comments (fixes #7693) (#7696) (Kai Cataldo)
- 034a575 Breaking: convert CLIEngine to ES6 class (refs #8231) (#8262) (Teddy Katz)
- 7dd890d Breaking: tweak space-before-function-paren default option (fixes #8267) (#8285) (Teddy Katz)
- 0e0dd27 Breaking: Remove
ecmaFeaturesfromeslint:recommended(#8239) (alberto) - 2fa7502 Breaking: disallow scoped plugin references without scope (fixes #6362) (#8233) (Teddy Katz)
- e232464 Breaking: change defaults for padded-blocks (fixes #7879) (#8134) (alberto)
Features
- 86cf3e4 New: no-buffer-constructor rule (fixes #5614) (#8413) (Teddy Katz)
Enhancements
- 8394e48 Update: add deprecated indent-legacy rule as v3.x indent rule snapshot (#8286) (Teddy Katz)
- f560c06 Update: fix space-unary-ops behavior with postfix UpdateExpressions (#8391) (Teddy Katz)
Bug Fixes
- 2754141 Fix: more autofix token-combining bugs (#8394) (Teddy Katz)
- 3c87e85 Fix: no-multi-spaces false positive with irregular indent whitespace (#8412) (Teddy Katz)
- 936af66 Fix: no-multiple-empty-lines crash on space after last \n (fixes #8401) (#8402) (Teddy Katz)
Documentation
- 950874f Docs: add 4.0.0 migration guide (fixes #8306) (#8313) (Teddy Katz)
- de9f1a0 Docs: ES6 syntax vs globals configuration (fixes #7984) (#8350) (Zander Mackie)
