Downloads

Fixed

• x && <Element/> no longer falsely reports E0026 (missing operand for
  operator). (Thanks to Piotr Dąbrowski for reporting.)
• In top-level code, await <x/> is now parsed as the await operator followed
  by a JSX element (rather than await less-than-compared to x, followed by
  jibberish).

Changed

• Homebrew: Emacs Lisp files are now installed in
  <brew>/share/emacs/site-lisp/quick-lint-js (per brew audit's
  recommendation) instead of in share/emacs/site-lisp.

Downloads

Fixed

• Curried arrow functions like a => b => { a; b; } no longer falsely reports
  E0057. (Thanks to Christian Mund for reporting.)

Downloads

Added

• quick-lint-js now supports JSX syntax in both .js and .jsx files.
• New diagnostics for JSX: E0019, E0181, E0182, E0183,
  E0186, E0187, E0189, E0191, E0192, E0193
• if (...) {...} else (...) {...} now reports E0184 ('missing if after
  else') (implemented by Himanshu).
• if (x = "") now reports E0188 ('= changes variables; to compare, use
  === instead').
• if (a == "X" || "Y") now reports E0190 ('missing comparison; === does
  not extend to the right side of ||').
• async (param1, param2) {} now reports E0176 ('missing arrow operator for
  arrow function'). (E0176 was previously reported only for non-async
  arrow functions.)
• let x = 'nah'; if (y) { let x = 'yah'; } now reports E0196 ('new
  variable shadows existing variable'). This warning is reported only when an
  assignment (instead of a new variable declaration) was intended.
• console.log(“hello world”); now reports E0197 (''“' is not allowed for
  strings; use " instead').
• -1 ** 2 now reports E0194 (missing parentheses around left-hand side of
  **).
• typeof 10 ** 7 now reports E0195 (missing parentheses around operand of
  typeof).

Fixed

• LSP: When responding to unsupported methods with error code -32601,
  quick-lint-js now includes the request ID. (Previously, the "id" field was
  always null.)
• CLI: If a crash occurs due to E0054 or E0203, the CLI no longer
  crashes (e.g. with an illegal instruction error).
• quick-lint-js no longer ignores elements of assigned arrays. For example,
  [fisrt, second] = s.split(' '); will now report E0057 for fisrt (if
  fisrt is not declared).
• quick-lint-js no longer incorrectly reports E0176 (missing arrow operator
  for arrow function) if the extends clause for a class is parenthesized
  and contains commas (e.g. class A extends (B, C) {}).
• quick-lint-js no longer incorrectly reports E0016, E0038, E0060,
  or E0207 in tagged template literals. (These errors are still reported for
  untagged template literals and for string literals.)

Changed

• Assigning to an imported variable now reports E0185 ('assignment to
  imported variable') instead of E0003 ('assignment to const variable')
  (implemented by Matheus de Sousa).

Downloads

Added

• Windows: Clang-cl is now able to compile quick-lint-js for Windows.
• E0176 is now reported if the desired arrow function has more than zero
  parameters.
• E0178 is now reported if the arrow function appears in top-level code or
  inside a non-async function.

Fixed

• Arch Linux: The quick-lint-js package now installs correctly if you have
  another Vim plugin package installed. The installation error was: "error: failed
  to commit transaction (conflicting files)"
• (typeof x)=>{} and similar code now reports E0151 (invalid function
  parameter) instead of E0019 (invalid binding in let statement).
• ([(x,)] => {}) now declares x as a parameter instead of ignoring x
  entirely. (It still produces E0180).
• \u0 at the end of a file now reports E0016 (expected hexadecimal digits
  in Unicode escape sequence) instead of E0038 (unclosed identifier escape
  sequence)
• "\u{00a0:" now reports only one error (E0038 (unclosed identifier escape
  sequence)) instead of two (E0038 and E0040 (unclosed string literal)).
• After reporting E0178, the arrow function is parsed as if it was async,
  allowing the body to use await as an operator without error.

Changed

• E0013 is no longer reported for identifiers such as bird\u{360000}.
  E0207 is reported instead.

Optimized

• The Windows .exe is 51% smaller (2.30 MiB -> 1.14 MiB) by making a hash table
  used for translations compile-time-only. See the patch
  here.

Beta release.

Downloads

Added

• npm: The npm package now installs on Windows when using the x86 (32-bit)
  version of Node.js.
• E0036 is now reported in more situations.

Fixed

• npm: The npm package now installs on macOS Apple silicon when using the
  AArch64 (native) version of Node.js. (The package previously worked only on
  macOS Intel, or when using x86_64 Node.js with Rosetta.)

Beta release.

Downloads

Security

• The source archive (quick-lint-js-*.tar.gz) is now signed with our GPG key.
• Arch Linux: The release package on AUR now verifies that the source archive is
  signed with our GPG key.

Added

• New diagnostics: E0053, E0179
• Improve error reporting of console.("hello") and similar code.
• Reported errors now include a link to the website for a detailed explanation
  (implemented by Amir).
• CLI: New --diagnostic-hyperlinks option (implemented by Amir).
• CLI: Fish and Zsh completions for the --output-format option now include
  documentation for each value (implemented by Amir).

Fixed

• Reporting E0144 no longer also reports E0057.
• Variables can be named according to Unicode 14 (previously Unicode 13).
• void 0?a:b=c no longer reports E0020.
• Vim: The Debian package, the Arch Linux package, and the Homebrew package now
  install the coc.nvim plugin and the plugin documentation.
• Neovim: Fixed with newer versions of nvim-lspconfig
  (since commit
  97da7ed12e
  published November 25, 2021).

Optimized

• Identifier parsing is now SIMD-optimized for ARM systems, including Apple
  silicon. See the patch
  here.
• Diagnostic message translations consume less space in executables and also
  take less time to process. See the patch
  here.
• Expression ASTs are now garbage-collected during parsing, reducing peak memory
  usage (and as a side effect making parsing faster). See the patch
  here.

Beta release.

Downloads

Added

• Various new diagnostics (implemented by Himanshu and Matheus de
  Sousa).
• VS Code: The new quick-lint-js.logging setting allows you to show
  quick-lint-js' internal log messages in an Output window.
• VS Code: Apple silicon (e.g. M1) (ARM64) is now supported.
• VS Code: Linux ARM (32-bit) is now supported.
• Vim: Improved performance for ALE versions v2.5.0 and newer (and v3.0.0 and
  newer). You should configure g:ale_lint_on_text_changed to 'always' for
  the best experience.
• Vim: Improved performance of the ALE plugin by using the LSP server by
  default.
• The macOS and Windows binaries are now code-signed.
• Emacs (Eglot): You no longer need to type M-x eglot in order to start
  linting. Apply this fix by adding (eglot-ensure) to your init
  file.
• quick-lint-js now understands the AggregateError, FinalizationRegistry,
  and WeakRef ECMAScript global variables by default.
• The macOS and Windows executables now include embedded code signatures. These
  signatures are made with a self-signed certificate.
• The Linux executables are now signed with a GPG signature (.asc files).
• Vim: coc.nvim is now supported.
• quick-lint-js has a new mascot, Dusty. Say hello! (Artwork by Jenny
  "Jennipuff" Wheat).
• Translations: German (implemented by Nico Sonack)

Fixed

• macOS: quick-lint-js no longer hangs if a file is changed in your home
  directory or project directory.
• Various crashes on invalid code have been fixed.
• quick-lint-js consumes less memory for pathological code patterns.
• VS Code: The extension no longer tries to load an ARM64 DLL on Windows x64.
• The npm package and the manual builds are now much smaller and faster. (They
  were previously compiled in debug, unoptimized mode.)
• delete x no longer reports a warning if x is a global variable.
• JSX: Instead of reporting a bunch of errors, quick-lint-js now tells you that
  JSX syntax is not yet supported.
• FreeBSD: Fixed build.
• E0073, E0094, E0104, E0106, E0111, and E0119 now point
  to a more helpful place (implemented by strager and Amir).
• for (let x = a in b; c; d) {} now reports E0108 instead of reporting
  E0173, E0110, and E0110 again.

Changed

• Error codes now have four decimal digits instead of three. For example, E001
  is now called E0001.
• LSP benchmarks have been rewritten. The new benchmarks should produce more
  stable numbers and be fairer to linters with a high start-up time such as
  Flow.

Removed

• quick-lint-js no longer looks for files named .quick-lint-js.config. To
  configure quick-lint-js, name your file quick-lint-js.config instead.

Beta release.

Downloads

Added

• Various new errors (implemented by Himanshu).
• quick-lint-js.config now supports the literally-anything global
  group. Use this option to disable all
  use-of-undeclared-variable warnings.
• If quick-lint-js crashes, it will link to a page to report
  crashes.
• VS Code: The plugin now works on Windows on ARM (64-bit).
• VS Code: The plugin now works on Linux on ARM (32-bit and 64-bit).
• The CLI and LSP server now compile on FreeBSD (amd64). However, we don't
  provide FreeBSD pre-built executables.
• Neovim: nvim-lspconfig is now supported by quick-lint-js' plugin (implemented
  by tiagovla).
• VS Code: Contributors can now enable performance
  tracing
  (implemented by Jimmy Qiu).

Fixed

• LSP, VS Code: Filesystem change watching failures no longer crash. These
  failures can happen on Windows for directories on network shares, for example.
• LSP: Unknown messages no longer crash the LSP server. This makes the LSP
  server compatible with more clients, such as Neovim's built-in client.
• break await and break yield no longer incorrectly reports errors (fixed by
  Himanshu).
• for (var x = ++y in []) {} now parses correctly as valid JavaScript.
• Vim: The plugin no longer crashes if a filename contains a newline character
  (or certain other control characters).
• LSP, VS Code: Config file changes are now recognized properly if any path
  component contains a symbolic link (Linux and macOS).
• quick-lint-js no longer warns about variables named __dirname,
  __filename, exports, module, or require by default.
• Parsing certain code patterns containing await/ no longer takes excessive
  memory and time.
• Various crashes on invalid code have been fixed.
• LSP, VS Code: Some memory leaks have been fixed.
• Arch Linux: building should no longer fail with "The install of the
  quick-lint-js target requires changing an RPATH from the build tree".

Beta release.

Downloads

Changed

• CLI: The --stdin option (and -) no longer search for configuration files
  in the current working directory. Use the --path-for-config-search option to
  approximate the old behavior.
• Emacs: For scratch buffers, the Flycheck and Flymake plugins no longer
  search for configuration files.
• Vim: For unnamed buffers, the ALE plugin no longer searches for configuration
  files in the current working directory's parent and ancestors. Name the buffer
  using the :file command if you want a configuration file to take effect.
• VS Code: The plugin has been rewritten. Performance should be better, but
  stability and compatibility might suffer. For example, VS Code on Apple
  silicon (AArch64 CPUs) has not been tested and will likely no longer work.
  Please report compatibility issues.

Added

• Various new errors (implemented by Himanshu)
• CLI: --path-for-config-search allows customizing where configuration files
  are found for --stdin
• Global variables for several popular libraries are now recognized by default,
  including jQuery, Jasmine, and Jest
• Syntax and schema errors in quick-lint-js.config no longer crash
  quick-lint-js. Instead, these errors are highlighted similar to errors in
  JavaScript files.
• VS Code: quick-lint-js.config is now used when linting opened JavaScript
  files.

Fixed

• Building quick-lint-js with AddressSanitizer on Fedora no longer fails in
  collect-copyright
• Building quick-lint-js no longer fails if a directory called brew exists
  anywhere in $PATH
• Various crashes given invalid JavaScript no longer happen (implemented by
  wagner riffel and David Vasileff)
• for (const x of xs) no longer incorrectly reports E205 (missing
  initializer in const declaration) (fixed by Himanshu)
• Windows: quick-lint-js.config files are now recognized if the containing
  directory contains non-ASCII characters
• Fix SSE2 corruption on 32-bit Windows builds with MSVC.

Beta release.

Downloads

Security

• Vim plugin: Version 0.2.0 executed node_modules/.bin/quick-lint-js without
  validating that the program is really quick-lint-js. The plugin now
  conservatively ignores quick-lint-js in node_modules by default.

Added

• New JS syntax: .?, class fields, import.meta, top-level await,
  #privateProperties
• Translations: Swedish (implemented by Kim "Linden")
• Emacs plugin (implemented by wagner riffel)
• Neovim plugin
• Errors and warnings are now documented on the website
• Various new errors and error message improvements (implemented by
  AidenThing, Daniel La Rocque, Erlliam Mejia, Himanshu, Lee
  Wannacott, [Matheus Sousa][])
• Shell completion for the CLI (Bash, Fish, Zsh) (implemented by Shivam
  Mehta)
• --stdin CLI option allows reading JavaScript from standard input instead of
  a file (implemented by wagner riffel)
• Partially implemented: Global variables can be configured using a
  quick-lint-js.config file

Fixed

• Using browser variables such as document and window no longer reports
  undesired undeclared variable warnings
• with statements and eval no longer cause spurious undeclared variable
  warnings (implemented by Himanshu)
• ++a[0]; no longer reports an assignment-to-const-variable error if a was
  declared with const (implemented by Himanshu)
• 'undefined' === typeof foo ? 3 : 4 no longer reports a warning that foo is
  undeclared (implemented by Himanshu)
• Building tests with GCC 11.1.1 no longer fails due to -Werror
• Various crashes given invalid JavaScript no longer happen
• Building the VS Code plugin now works on Windows (implemented by Jimmy
  Qiu)