quick-lint-js

This document chronicles quick-lint-js' releases. This document's format is based on Keep a Changelog.

quick-lint-js' version numbers are arbitrary. quick-lint-js does not adhere to Semantic Versioning.

Unreleased

Added

• LSP server: quick-lint-js can now receive configuration options via the initialize request. See LSP configuration documentation for details.

Fixed

• Emacs (Flycheck): Using C-x C-; to comment a line now runs quick-lint-js (instead of leaving old diagnostics on the screen). This requires that you update your Emacs file: add new-line to the flycheck-check-syntax-automatically variable.

2.14.0 (2023-05-22)

Downloads

Added

• Missing props in JSX tags now report E0376 ("JSX prop is missing an expression"). (Implemented by James Moles.)
• ! == (with a space) now reports E0373 or E0374. (Implemented by daethtech.)
• x == y ?? true now reports E0369. (Implemented by Kate Conkright.)
• apt install quick-lint-js now works on ARM64 (AArch64) Debian and Ubuntu installations.
• TypeScript support (still experimental):
  • Certain invalid parameter properties (such as in constructor(public {id, name})) now report diagnostics.
  • function f(a?, b) {} now reports E0379. (Implemented by Alek Lefebvre.)

Fixed

• Arrow functions with TypeScript parameter type annotations no longer report confusing diagnostics in JavaScript mode. (Implemented by Leszek Nowicki.)
• TypeScript support (still experimental):
  • '`hello${world}` as const' no longer falsely reports E0291. (Fixed by Leszek Nowicki.)
• Windows: Fixed a build failure with MinGW GCC 13.1.0.
• Shell completions are now up to date with the CLI. (Fixed by Jake Castelli.)
• FreeBSD: quick-lint-js no longer fails to build.

Changed

• Ubuntu 18.04 LTS Bionic is no longer supported. It might happen to work, but it is not extensively tested. Canonical is itself ending support for Bionic on May 31, 2023, so please upgrade to Ubuntu 20.04 LTS or newer.

2.13.0 (2023-04-13)

Downloads

Known issues

• Building quick-lint-js on FreeBSD is broken.

Added

• quick-lint-js now recognizes Deno's global variables, including Deno. This suppresses undesired E0057 ("use of undeclared variable") warnings. This is controlled by the deno global group.
• if () {} (without a condition) now reports E0452 ("empty parenthesis after control statement"). (Implemented by Yunus.)
• return x, now reports E0026 ("missing operand for operator"). (Implemented by Tom Binford.)
• TypeScript support (still experimental):
  • The satisfies operator is now recognized.
  • The infer operator is now recognized.
  • The in and out keywords for generic parameter variance are now recognized.
  • Parameter properties (constructor(public readonly name: string, public age: number)) are now recognized.
  • C<T>=y; now reports E0365 ("TypeScript requires whitespace between '>' and '=' here").
  • extends in interface now allows generic arguments, such as in interface I extends T<U> {}.
  • extends in interface now allows nested namespaces, such as in interface I extends ns1.ns2.ns3.I {}.
• FreeBSD: quick-lint-js --debug-apps now works. (Implemented by Nico Sonack.)

Fixed

• Fixed several false errors:
  • do while (x); while (y); no longer falsely reports E0101 ("missing body for do-while loop").
  • { var async; async } no longer falsely reports E0054 ("unexpected token").
  • async[x] no longer falsely reports E0054 ("unexpected token").
  • await x ? y : z no longer falsely reports E0311 ("missing parentheses around parameter").
  • if (c) async () => {}; else {} no longer falsely reports E0065 ("'else' has no corresponding 'if'").
  • class A extends await {} no longer falsely reports E0111 ("missing body for class").
  • class A extends await() {} no longer falsely reports E0176 ("missing arrow operator for arrow function").
  • do if (c) {} else (b); while (d); no longer falsely reports E0103 ("missing 'while (condition)' for do-while statement").
• if (c) {} else (b) d; now correctly reports E0027 ("missing semicolon after statement").
• The CLI's --output-format=gnu-like output (default) no longer prints terminal escape sequences for "dumb" terminals (where TERM=dumb). (Fixed by wagner riffel.)
• FreeBSD: The quick-lint-js-licenses.txt file is now populated correctly.
• TypeScript support (still experimental):
  • let x: C<T>=y; no longer falsely reports an error.
  • class A extends B<C> {} no longer falsely reports an error.
  • T extends keyof O ? A : B no longer falsely reports an error.

Changed

• Cross compiling now requires you to build with QUICK_LINT_JS_ENABLE_BUILD_TOOLS for the build machine then with QUICK_LINT_JS_USE_BUILD_TOOLS for the target machine. See the cross-compiling documentation for details.
• Code signing certificate has been refreshed. The old certificate expires on April 18, 2023 (PDT) and the new certificate expires on April 17, 2024 (PDT). The public key is the same between the two certificates: 7ea531a42cd3e7161b6951f93d83449546e90722 (SHA1).

2.12.0 (2023-03-08)

Downloads

Added

• array[i, j] now reports E0450 ("misleading use of ',' operator in index") (implemented by Yunus).
• while (x > 0, y > 0) now reports E0451 ("misleading use of ',' operator in conditional statement") (implemented by Yunus).
• Improvements to experimental TypeScript support:
  • Type variables such as Readonly<T> and IArguments are now recognized by the new typescript global group which is enabled by default.
  • declare is now supported.
  • The old-style module syntax for namespaces is now supported.

Fixed

• Fixed E0062 being reported when E0061 should be reported instead (fixed by Yunus).
• TypeScript namespace without a body now reports E0356 instead of crashing with an assertion failure.

Changed

• quick-lint-js' build system now optionally creates executes and runs them during the build. This behavior is controlled by the QUICK_LINT_JS_ENABLE_BUILD_TOOLS and QUICK_LINT_JS_USE_BUILD_TOOLS CMake variables.
  • For most people, QUICK_LINT_JS_ENABLE_BUILD_TOOLS is enabled by default and should work without extra configuration. No action is needed.
  • When cross-compiling, QUICK_LINT_JS_ENABLE_BUILD_TOOLS is disabled. Currently, QUICK_LINT_JS_ENABLE_BUILD_TOOLS is optional, so this should behave as before. However, in the future, either QUICK_LINT_JS_ENABLE_BUILD_TOOLS or QUICK_LINT_JS_USE_BUILD_TOOLS will be required.
  • If you need to configure the build tools specially, or if you want to build the build tools when cross-compiling, you must use the QUICK_LINT_JS_USE_BUILD_TOOLS CMake variable. See the cross-compiling documentation for instructions on using QUICK_LINT_JS_USE_BUILD_TOOLS correctly.

2.11.0 (2023-01-31)

Downloads

Changed

• Debian: The apt repository signing key expired on (2023-01-21). This causes apt-get update to fail. To fix this issue, add the latest signing key by running the following command:

  $ curl https://c.quick-lint-js.com/quick-lint-js-release.key | sudo apt-key add -
  

• LSP: The quick-lint-js LSP server no longer accepts JSON-RPC 2.0 batch messages. In practice, LSP clients don't use this feature, so this breaking change should do no harm. The LSP specification recently started prohibiting batch messages to match the status quo.

Added

• LSP: The LSP server now recognizes and lints TypeScript and TypeScript JSX code. However, the editor plugins currently do not use this feature by default.
• Vim: You can opt into TypeScript support. Search for EXPERIMENTAL in :help quick-lint-js. (Disabled by default.)
• VS Code: You can now opt into experimental TypeScript support. Set the quick-lint-js.experimental-typescript setting to true. (Disabled by default.)
• switch (c) { case A: break; case A: break; } now reports E0347 ("duplicated case clause in switch statement") (implemented by Rebraws).
• Translations: Brazilian Portuguese (implemented by Guilherme Vasconcelos).
• Mixing up the order of the export, async, and function keywords now reports E0326 or E0327 (implemented by Alek Lefebvre).
• TypeScript types like string? now report E0348 (implemented by Alek Lefebvre).
• Extra parentheses in function parameters now report E0349 (function parameter cannot be parenthesized) (implemented by Harshit Aghera).
• QuickJS's global variables are now recognized by default via the new quickjs global group (implemented by wagner riffel).
• E0190 is now reported if the literal is undefined, not only null, strings, and numbers (implemented by Harshit Aghera).

Fixed

• Variables can be named according to Unicode 15 (previously Unicode 14).
• In tracing files, the thread IDs in the file headers are now correct if tracing was enabled after startup.
• E0325 is now an error rather than a warning.
• 0o123.toString(), 0x123.toString(), 0b101.toString(), and 0123.toString() no longer incorrectly report E0046, E0047, or E0048.
• Using a variable called async, then exporting something, no longer reports an unexpected token error (implemented by Alek Lefebvre).
• class C { x = 0, y; } now reports E0330 ("',' should be ';' instead") instead of E0057 ("use of undeclared variable: y") (implemented by clegoz).

2.10.0 (2022-10-14)

Downloads

Added

• E0286 and E0287 are now reported if the string or the value have extra parentheses (such as in (tag.toUpperCase()) === 'img') (implemented by Rebraws).
• myArray === [] now reports E0344 (implemented by Rebraws).
• myArray === [a, b, c] now reports E0341 (implemented by Rebraws).
• CLI: The new --language option lets you opt out of JSX support. With --language=javascript, quick-lint-js will report E0177 for any uses of JSX.
• You can opt into TypeScript support in the CLI using the --language=experimental-typescript option. TypeScript support is experimental, so there will be bugs (including crashes) in quick-lint-js. This option does not affect the LSP server.
• E0149 and E0150 are now reported for labelled statements too (implemented by Guilherme Vasconcelos).

Fixed

• static code blocks in classes no longer report E0242 ("TypeScript static blocks are not supported in JavaScript").
• When writing implements in JavaScript code, quick-lint-js will no longer possibly report E0246 in addition to E0247. quick-lint-js will now only report E0247.
• { x: y = z } in an expression no longer incorrectly reports E0253.
• { x: y = z } now reports errors such as E0057 for z. (z used to be completely ignored during variable analysis.)
• { x = z } now only reports E0253, instead of also reporting E0059 for x.
• class C { field!; } now only reports E0239 (TypeScript assignment-asserted fields are not supported in JavaScript) instead of both E0239 and E0236 (assignment-asserted field must have a type annotation).

Changed

• E0707 has been merged into E0069.
• E0271 has been merged into E0270.
• E0279 has been merged into E0278.

2.9.0 (2022-09-05)

Downloads

Added

• tag.toUpperCase() === 'img' now reports E0286, and tag.toLowerCase() === 'IMG' now reports E0287 (implemented by Roland Strasser).

Fixed

• (param) { body(); } now reports E0176 ('missing arrow operator for arrow function') (implemented by Roland Strasser).
• quick-lint-js no longer crashes if a TypeScript type alias appears in a JavaScript file.
• quick-lint-js now recognizes the jest global variable from the Jest test framework. This suppresses undesired E0057 ("use of undeclared variable") warnings.
• await () => x no longer reports x as undeclared multiple times. (E0178 is still reported, as intended.)
• Defining a global variable in quick-lint-js.config which is already declared by default now always changes the shadowable and writable settings.
• await () => await () => ... no longer slows down linting and consumes a lot of memory.

2.8.0 (2022-07-25)

Downloads

Added

• await await f() now reports E0266 ("redundant await") (implemented by clegoz).
• CLI: Misuse of --vim-file-bufnr now reports warnings (implemented by Roland Strasser).

Fixed

• LSP, VS Code: quick-lint-js now correctly handles merging lines containing non-ASCII with lines containing ASCII. This fixes spurious diagnostics. Thanks to T0x3139 and mirabellier for reporting and helping fix this bug.
• quick-lint-js now recognizes Bun's global variables, including Bun and bunJSX. This suppresses undesired E0057 ("use of undeclared variable") warnings.

Removed

• The en@loud translation has been removed. It was only used for testing.

Changed

• Debian/Ubuntu: Our Debian/Ubuntu package now might not work on Ubuntu 16.04 or Debian 9. The following Debian-based Linux distributions are tested:
  • Debian 10 Bullseye and 11 Buster
  • PureOS Amber
  • Ubuntu 18.04 Bionic and 20.04 Focal
• Manual: Our Linux x86_64/amd64 pre-built binaries now might not work on Ubuntu 16.04 or similarly old distributions. The following Linux distributions are tested:
  • Arch Linux
  • Debian 10 Bullseye and 11 Buster
  • Fedora 35 and 36
  • Ubuntu 18.04 Bionic and 20.04 Focal

2.7.0 (2022-07-13)

Downloads

Added

• const o = {k = v}; now reports E0253 ("use ':' instead of '=' in object literals").
• --snarky is now even snarkier.
• LSP server: The new quick-lint-js.tracing-directory LSP configuration item can be set to a path where quick-lint-js will log LSP protocol traffic. This keylogger option can be used by quick-lint-js contributors to investigate bugs. This new option is disabled by default.

Fixed

• quick-lint-js no longer fails to build with simdjson version 2.2.0.
• Declaring a TypeScript interface with the same name as a generic parameter no longer crashes quick-lint-js.

2.6.0 (2022-06-15)

Downloads

Added

• DOMError, MutationEvent, and some other browser global variables are now recognized.
• New global group: web-worker (enabled by default)
• The importScripts global function is now recognized by default.
• Forgetting a semicolon between class fields now reports "missing semicolon after field" (E0223) instead of "missing semicolon after statement" (E0027).
• Using some TypeScript features, such as class generics and interfaces, in JavaScript code is now reported with a friendly error message.
• E0199 ("unclosed class") is now reported in more scenarios.
• static code blocks in classes are now supported.

Fixed

• E0707 now only complains about classes named await, not any class inside an async function.
• E0054 is no longer incorrectly reported for class properties named implements, interface, package, private, protected, or public.
• In statement contexts, async followed by a newline followed by function is no longer falsely interpreted as an async function. It is instead interpreted as the use of a variable called async followed by a non-async function, per the language standard.
• ((x)) => {} no longer crashes the parser with an assertion failure.
• Tests now pass if the user's locale is Italian (it_IT.utf8 on Linux).
• The FreeBSD build now succeeds and tests pass.

2.5.0 (2022-05-23)

Downloads

Added

• E0144 and E0145 are now reported for implements, interface, package, private, protected, and public (in addition to other keywords).
• E0086 is now reported in more cases, such as when the deleted variable was declared outside the function containing the delete expression.
• Classes named await in async functions now report E0707 (implemented by ooblegork).
• Integer literals which are silently rounded at run-time now report E0212 (implemented by Rob Miner).
• VS Code: The new quick-lint-js.tracing setting can be set to "verbose" to log changes to documents. This keylogger option can be used by quick-lint-js contributors to investigate bugs. This new option is disabled by default.
• CLI: The --snarky option makes error messages more interesting. Implemented by david doroz.

Fixed

• E0150 no longer crashes quick-lint-js when using a German (de) locale. (Fixed by Nico Sonack.)
• The npm package now includes copyright files listing software licenses and copyright notices.
• E0086 is no longer falsely reported in some cases.
• VS Code (Windows x64): When the extension is first loaded, and a file has errors, quick-lint-js no longer reports the first error always on the first line. (The issue was a compiler bug which we worked around.)
• quick-lint-js no longer creates and writes messages to /tmp/qljs.log.

Changed

• This release is signed with a new GPG key.
  • Old fingerprint: 0327DE8F9CEF499851D19F6ED20BA9DCCF0E9D20
  • New fingerprint: A6851D57A65803E98C05DA01C08A7BC89CA2F557

2.4.2 (2022-04-22)

Downloads

Changed

• The name of package installed by the MSIX installer has changed. It used to be "fa6b940b-8f96-4b46-8e21-703a63133e06" but now it is "quick-lint.quick-lint-js". If you installed quick-lint-js using a prior version of the MSIX installer, Windows won't let you upgrade. Uninstall the old version of quick-lint-js before installing a new version.

2.4.1 (2022-04-19)

Downloads

Fixed

• When using the de, fr_FR, or sv_SV locale, some error messages are no longer blank.

Changed

• The Windows MSIX installer is now signed with a Microsoft-trusted certificate. If you installed quick-lint-js using a prior version of the MSIX installer, Windows won't let you upgrade. Uninstall the old version of quick-lint-js before installing a new version.
• The Windows executable is now signed with a Microsoft-trusted certificate.

2.4.0 (2022-04-15)

Downloads

Added

• Missing parentheses around a self-invoked arrow function are now reported as E0211. (Implemented by Sarah Schulte.)
• E0179 is now reported if a JSX element such as <div /> follows return (implemented by Rob Miner).

Fixed

• <div> <> </> </div> (a JSX fragment inside a JSX element) no longer reports a syntax error.

Changed

• Windows builds (x86, x64, ARM, and ARM64) are now built with MinGW's C and C++ runtime libraries instead of Microsoft's. This fixes a compliance issue with GPLv3.

2.3.1 (2022-03-24)

Downloads

Added

• Windows: The 32-bit x86 builds are now code-signed.
• Windows: Tab-completion now works in PowerShell. (Completion needs to be installed manually.) (Implemented by Tony Sathre.)

Fixed

• The executable files shared between the npm packages and the static builds are now identical. (Previously, the files sometimes differed because they were code-signed independently. Code signing is non-deterministic.)

2.3.0 (2022-02-24)

Downloads

Added

• An incomplete class now reports E0199 instead of failing with the catch-all E0054. (Thanks to Dave Churchill for reporting.)
• Statements before the first case in a switch now report E0198 (implemented by Himanshu).
• When building from source, you can tell quick-lint-js to use your copy of third-party dependencies instead of quick-lint-js' bundled dependencies:
  • -DQUICK_LINT_JS_USE_BUNDLED_BOOST=OFF: Use your own copy of Boost.
  • -DQUICK_LINT_JS_USE_BUNDLED_GOOGLE_BENCHMARK=OFF: Use your own copy of Google Benchmark (benchmarks only).
  • -DQUICK_LINT_JS_USE_BUNDLED_GOOGLE_TEST=OFF: Use your own copy of Google Test (tests only).
  • -DQUICK_LINT_JS_USE_BUNDLED_SIMDJSON=OFF: Use your own copy of simdjson.

2.2.0 (2022-02-17)

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.

2.1.0 (2022-02-09)

Downloads

Fixed

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

2.0.0 (2022-02-08)

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).

1.0.0 (2021-12-13)

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.

0.7.1 (2021-12-06)

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.)

0.7.0 (2021-12-05)

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.

0.6.0 (2021-11-20)

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.

0.5.0 (2021-10-12)

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".

0.4.0 (2021-09-09)

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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.

0.3.0 (2021-07-02)

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 de 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)

0.2.0 (2021-04-05)

Downloads