ESLint 0.4.0 released

We just pushed ESLint 0.4.0, which is a significant release due to the number of bug fixes and significant changes included.

Configuration Files

• Configuration files can now be written in YAML. This includes .eslintrc files.
• All configuration files can be in either JSON or YAML format, no special indicator of the format is necessary

Core

• Breaking Change: Changed :after in node selectors to be :exit instead
• Switch to using optionator instead of optimist for CLI input
• Split out ESLintTester into its own repository (https://github.com/eslint/eslint-tester)
• CLI used to output a single blank line when there were no errors, now it doesn’t output anything in this case

Performance

• Implementing benchmarks to help identify performance bottlenecks
• Refactoring allowed a 400-700ms improvement on our benchmarks

Rules

• Breaking Change: unnecessary-strict rule was renamed to no-extra-strict
• Breaking Change: regex-spaces rule was renamed to no-regex-spaces
• Breaking Change: no-new-array rule was renamed to no-array-constructor
• New Rule: valid-jsdoc (fixes #536) (Nicholas C. Zakas)
• New Rule: func-names (fixes #595) (Kyle Nunery)
• New Rule: no-extra-boolean-cast (fixes #557) (Brandon Mills)
• New Rule: no-sparse-arrays (fixes #499) (Nicholas C. Zakas)
• New Rule: no-process-exit (fixes #568) (Nicholas C. Zakas)
• New Rule: no-labels (fixes #550) (Nicholas C. Zakas)
• New Rule: no-lone-blocks (fixes #512) (Brandon Mills)
• New Rule: no-path-concat (fixes #540) (Nicholas C. Zakas)
• New Rule: no-yoda (fixes #504) (Nicholas C. Zakas)
• New Rule: consistent-return (fixes #481) (Nicholas C. Zakas)
• There was a bug in no-unused-vars that would incorrectly flag unused parameters in the case of nested functions - this was fixed
• There was a bug in no-cond-assign that could result in an error being thrown - this was fixed
• All rules now have documentation and build will fail if a rule is added without documentation

Other

• Created Yeoman generator to help create new rules

Breaking Changes

The complete list of breaking changes are as follows:

• unnecessary-strict rule was renamed to no-extra-strict
• regex-spaces rule was renamed to no-regex-spaces
• no-new-array rule was renamed to no-array-constructor
• Changed :after in node selectors to be :exit instead

Complete Changelog

The following is the complete list of changes in this version:

• Change: Switch :after to :exit (fixes #605) (Nicholas C. Zakas)
• Fix: Make sure no-unused-vars doesn’t get confused by nested functions (fixes #584) (Nicholas C. Zakas)
• Update: .eslintrc to check more things (Nicholas C. Zakas)
• Fix: Make sure JSDoc parser accepts JSDoc3-style optional parameters (Nicholas C. Zakas)
• Docs: Update documentation with linking instructions for ESLintTester (Nicholas C. Zakas)
• New Rule: valid-jsdoc (fixes #536) (Nicholas C. Zakas)
• #595 improved func-names documentation (Kyle Nunery)
• #595 added more func-names tests (Kyle Nunery)
• #595 fix rule message and add more tests (Kyle Nunery)
• use optionator for option parsing, not optimist (George Zahariev)
• Include instructions for working with ESLintTester (Nicholas C. Zakas)
• #595 remove needless ‘function Foo() {}’ in tests (Kyle Nunery)
• #595 fix whitespace (Kyle Nunery)
• #595 fix markdown for js code blocks (Kyle Nunery)
• Adding information about Yeomen generator (Ilya Volodin)
• #595 add docs for rule func-names (Kyle Nunery)
• #595 add func-names rule (Kyle Nunery)
• migrate variables array to map (Brandon Mills)
• Perf: Move try-catch out of verify() function to allow V8 optimization (refs #574) (Nicholas C. Zakas)
• Docs: Added instructions for running npm run profile (Nicholas C. Zakas)
• refactor variable name lookup into a separate function (Brandon Mills)
• optimize findVariable() in no-unused-vars (Brandon Mills)
• move to tests/bench (Chris Dickinson)
• add npm run profile. (Chris Dickinson)
• #586 refactor based on https://github.com/eslint/eslint/pull/590#discussion_r9476367 (Christian)
• #586 added no-unreachable jsdoc, documentation note on hoisting case (Christian)
• #586 add hoisting check to no-unreachable (Christian)
• readme: Remove stray asterisk (Timo Tijhof)
• #580 Remove eslint.getAllComments(), related docs, related tests (Christian)
• Added test for bug fix #582. Test Passes (Shmueli Englard)
• Added curly braces to if statment (Shmueli Englard)
• Added new test for fix to #582 (fixes 582) (Shmueli Englard)
• Bug #582: Added check if node.value isn’t a string just exit (Shmueli Englard)
• Update Rule: implement curly options for single-statement bodies (fixes #511) (Nicholas C. Zakas)
• New Rule: no-extra-boolean-cast (fixes #557) (Brandon Mills)
• New Rule: no-sparse-arrays (fixes #499) (Nicholas C. Zakas)
• Fix: no-spaced-func is now an error (Nicholas C. Zakas)
• New Rule: no-process-exit (fixes #568) (Nicholas C. Zakas)
• New Rule: no-labels (fixes #550) (Nicholas C. Zakas)
• New Rule: no-lone-blocks (fixes #512) (Brandon Mills)
• Added Emacs/Flycheck integration (Nikolai Prokoschenko)
• Build: Add perf test (Nicholas C. Zakas)
• Fix: no-cond-assign shouldn’t throw error when there’s a for loop with an empty conditional (fixes #53) (Nicholas C. Zakas)
• Docs: Add docs for no-regex-spaces and all doc errors now break build (closes #562) (Nicholas C. Zakas)
• Rename: regex-spaces to no-regex-spaces (Nicholas C. Zakas)
• Docs: Add docs for no-underscore-dangle (refs #562) (Nicholas C. Zakas)
• Docs: Add docs for no-undef-init (refs #562) (Nicholas C. Zakas)
• Docs: Add docs for no-return-assign (refs #562) (Nicholas C. Zakas)
• Fix: Misspelling in no-return-assign message (Nicholas C. Zakas)
• Docs: Add docs for no-new-wrappers (refs #562) (Nicholas C. Zakas)
• Docs: Add docs for no-new-object (refs #562) (Nicholas C. Zakas)
• Docs: Add docs for no-implied-eval (refs #562) (Nicholas C. Zakas)
• Docs: Updated documentation for developing rules (Nicholas C. Zakas)
• Testing: Move ESLintTester to be external dependency (fixes #480) (Nicholas C. Zakas)
• Docs: Add list of known integrations (Nicholas C. Zakas)
• Fix #570 (dmp42)
• document no-array-constructor rule (Michael Ficarra)
• fixes #500: no-array-constructor should not flag 1-argument construction (Michael Ficarra)
• fixes #501: no-array-constructor recognises CallExpression form (Michael Ficarra)
• rename no-new-array rule to no-array-constructor; ref #501 (Michael Ficarra)
• Fix: Make radix rule warn on invalid second parameter (fixes #563) (Nicholas C. Zakas)
• Docs: Added no-floating-decimal docs (refs #562) (Nicholas C. Zakas)
• New Rule: no-path-concat (fixes #540) (Nicholas C. Zakas)
• Docs: Add some missing rule docs (refs #562) (Nicholas C. Zakas)
• Fix: CLI should not output anything when there are no warnings (fixes #558) (Nicholas C. Zakas)
• New Rule: no-yoda (fixes #504) (Nicholas C. Zakas)
• New Rule: consistent-return (fixes #481) (Nicholas C. Zakas)
• Rewrite configuration documentation to include information about globals (fixes #555) (Nicholas C. Zakas)
• Allow YAML configuration files (fixes #491) (Nicholas C. Zakas)