79d3276f61
* refactor: inline pushComment * chore: add benchmark cases * perf: overhaul comment attachment * cleanup * update test fixtures They are all bugfixes. * fix: merge HTMLComment parsing to skipSpace * perf: remove unattachedCommentStack baseline 128 nested leading comments: 11_034 ops/sec ±50.64% (0.091ms) baseline 256 nested leading comments: 6_037 ops/sec ±11.46% (0.166ms) baseline 512 nested leading comments: 3_077 ops/sec ±2.31% (0.325ms) baseline 1024 nested leading comments: 1_374 ops/sec ±3.22% (0.728ms) current 128 nested leading comments: 11_027 ops/sec ±37.41% (0.091ms) current 256 nested leading comments: 6_736 ops/sec ±1.39% (0.148ms) current 512 nested leading comments: 3_306 ops/sec ±0.69% (0.302ms) current 1024 nested leading comments: 1_579 ops/sec ±2.09% (0.633ms) baseline 128 nested trailing comments: 10_073 ops/sec ±42.95% (0.099ms) baseline 256 nested trailing comments: 6_294 ops/sec ±2.19% (0.159ms) baseline 512 nested trailing comments: 3_041 ops/sec ±0.8% (0.329ms) baseline 1024 nested trailing comments: 1_530 ops/sec ±1.18% (0.654ms) current 128 nested trailing comments: 11_461 ops/sec ±44.89% (0.087ms) current 256 nested trailing comments: 7_212 ops/sec ±1.6% (0.139ms) current 512 nested trailing comments: 3_403 ops/sec ±1% (0.294ms) current 1024 nested trailing comments: 1_539 ops/sec ±1.49% (0.65ms) * fix: do not expose CommentWhitespace type * add comments on CommentWhitespace * add test case for #11576 * fix: mark containerNode be the innermost node containing commentWS * fix: adjust trailing comma comments for Record/Tuple/OptionalCall * fix: drain comment stacks in parseExpression * docs: update comments * add a new benchmark * chore: containerNode => containingNode * add more benchmark cases * fix: avoid finishNodeAt in stmtToDirective * finalize comment right after containerNode is set * add testcase about directive * fix: finish SequenceExpression at current pos and adjust later * chore: rename test cases * add new test case on switch statement * fix: adjust comments after trailing comma of function params * add comment attachment design doc * misc fix * fix: reset previous trailing comments when parsing async method/accessor * chore: add more comment testcases * fix flow errors * fix: handle comments when parsing async arrow * fix: handle comments when "static" is a class modifier * fix flow errors * fix: handle comments when parsing async function/do * refactor: simplify resetPreviousNodeTrailingComments * update test fixtures
The compiler for writing next generation JavaScript.
Supporting Babel
Babel (pronounced "babble") is a community-driven project used by many companies and projects, and is maintained by a group of volunteers. If you'd like to help support the future of the project, please consider:
- Giving developer time on the project. (Message us on Twitter or Slack for guidance!)
- Giving funds by becoming a sponsor on Open Collective or Patreon!
Sponsors
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Intro
Babel is a tool that helps you write code in the latest version of JavaScript. When your supported environments don't support certain features natively, Babel will help you compile those features down to a supported version.
In
// ES2020 nullish coalescing
function greet(input) {
return input ?? "Hello world";
}
Out
function greet(input) {
return input != null ? input : "Hello world";
}
Try it out at our REPL.
FAQ
Who maintains Babel?
Mostly a handful of volunteers, funded by you! Please check out our team page!
Is there a Babel song?
I'm so glad you asked: Hallelujah —— In Praise of Babel by @angus-c, audio version by @swyx. Tweet us your recordings!
Looking for support?
For questions and support please join our Slack Community (you can sign up here for an invite), ask a question on Stack Overflow, or ping us on Twitter.
Where are the docs?
Check out our website: babeljs.io, and report issues/features at babel/website.
Want to report a bug or request a feature?
Please read through our CONTRIBUTING.md and fill out the issue template at babel/issues!
Want to contribute to Babel?
Check out:
- Our #development Slack channel and say hi! (sign-up)
- Issues with the good first issue and help wanted label. We suggest also looking at the closed ones to get a sense of the kinds of issues you can tackle.
Some resources:
- Our CONTRIBUTING.md to get started with setting up the repo.
- Our discussions/notes/roadmap: babel/notes
- Our progress on TC39 proposals: babel/proposals
- Our blog which contains release posts and explanations: /blog
- Our videos page with talks about open source and Babel: /videos
- Our podcast
How is the repo structured?
The Babel repo is managed as a monorepo that is composed of many npm packages.