npmpackage.info

Gathering detailed insights and metrics for @babel/preset-modules

Gathering detailed insights and metrics for @babel/preset-modules

@babel/preset-modules - 0.1.6 | npmpackage.info

@babel/preset-modules

A Babel preset that targets modern browsers by fixing engine bugs (will be merged into preset-env eventually)

0.1.6

741

MIT

JavaScript

37.92 kB

Installations

npm install @babel/preset-modules

Developer Guide

BETA

Typescript

No

Module System

CommonJS

Node Version

20.4.0

NPM Version

9.7.2

Pull Requests

Open

2

Total

22

Closed

9

Merged

11

Issues

Open

3

Total

15

Closed

12

Releases

6

0.1.5

Updated on Oct 21, 2021

0.1.4

Updated on Aug 27, 2020

0.1.3

Updated on Feb 10, 2020

0.1.2

Updated on Dec 15, 2019

0.1.1

Updated on Nov 19, 2019

0.1.0

Updated on Nov 19, 2019

View All 6 releases

Languages

1

JavaScript

JavaScript (100%)

Developer

babel

Download Statistics

Total Downloads

0

Last Day

0

Last Week

0

Last Month

0

Last Year

0

GitHub Statistics

MIT License

741 Stars

42 Commits

17 Forks

24 Watchers

4 Branches

35 Contributors

Updated on Jun 01, 2025

Maintainers

5

View All 35 Contributors

Package Meta Information

Latest Version

0.1.6

Package Id

@babel/preset-modules@0.1.6

Unpacked Size

37.92 kB

Size

9.79 kB

File Count

19

NPM Version

9.7.2

Node Version

20.4.0

Published on

Jul 21, 2023

Total Downloads

Cumulative downloads

Total Downloads

NaN

Last Day

0%

NaN

Compared to previous day

Last Week

0%

NaN

Compared to previous week

Last Month

0%

NaN

Compared to previous month

Last Year

0%

NaN

Compared to previous year

Weekly Downloads

Monthly Downloads

Yearly Downloads

`@babel/preset-modules`

ℹ️ Starting from @babel/preset-env 7.9.0, you can enable the bugfixes: true option to get the same behavior as using @babel/preset-modules, but with support for custom targets. If you need to target browsers with native modules support (like this preset does), you can use targets: { esmodules: true }.

A Babel preset that enables async/await, Tagged Templates, arrow functions, destructured and rest parameters, and more in all modern browsers (88% of traffic).

It works around bugs and inconsistencies in modern JavaScript engines by converting broken syntax to the closest non-broken modern syntax. Use this in place of @babel/preset-env's target.esmodules option for smaller bundle size and improved performance.

This preset is only useful for browsers. You can serve the output to modern browsers while still supporting older browsers using the module/nomodule pattern:

1<!-- transpiled with preset-modules: -->
2<script type="module" src="modern.js"></script>
3<!-- transpiled with preset-env: -->
4<script nomodule src="legacy.js"></script>

Features Supported

JSX spread attributes are compiled to Object.assign() instead of a helper.
Default, destructured and optional parameters are all natively supported.
Tagged Templates are fully supported, patched for Safari 10+ and Edge 16+.
async/await is supported without being transpiled to generators.
Function name inference works as expected, including Arrow Functions.

Installation & Usage

Install the preset from npm:

1npm install @babel/preset-modules --save-dev

To use the preset, add it to your Babel Configuration:

1{
2  "presets": [
3    "@babel/preset-modules"
4  ]
5}

If you're implementing the module/nomodule pattern, your configuration might look something like this:

1{
2  "env": {
3    "modern": {
4      "presets": [
5        "@babel/preset-modules"
6      ]
7    },
8    "legacy": {
9      "presets": [
10        "@babel/preset-env"
11      ]
12    }
13  }
14}

Options

There's a single Boolean loose option, which defaults to false. Passing true further reduces output size.

The loose setting turns off a rarely-needed function name workaround for older versions of Edge. If you're not relying on Function.prototype.name, it's worth enabling loose mode.

How does it work?

Babel’s preset-env is great, since it lets you define which Babel features are needed based on a browser support target. In order to make that plumbing work automatically, the preset has configuration that groups all of the new JavaScript syntax features into collections of related syntax transforms. These groups are fairly large, for example "function arguments" includes destructured, default and rest parameters. The groupings come from the fact that Babel’s transforms often rely on other transforms, so they can’t always be applied in isolation.

From this grouping information, Babel enables or disables each group based on the browser support target you specify to preset-env’s targets option. For modern output, the targets.esmodules option is effectively an alias for the set of browsers that support ES Modules: Edge 16+, Safari 10.1+, Firefox 60+ and Chrome 61+.

Here's the problem: if any version of any browser in that list contains a bug triggered by modern syntax, the only solution we have is to enable the corresponding transform group that fixes that bug. This means that fundamentally, preset-env converts code to ES5 in order to get around syntax bugs in ES2017. Since that's the only solution at our disposal, eventually it becomes overused.

For example, all of the new syntax features relating to function parameters are grouped into the same Babel plugin (@babel/plugin-transform-function-parameters). That means because Edge 16 & 17 support ES Modules but have a bug related to parsing shorthand destructured parameters with default values within arrow functions, all functions get compiled from the new compact argument syntaxes down to ES5:

1// this breaks in Edge 16:
2const foo = ({ a = 1 }) => {};
3
4// .. but this doesn't:
5function foo({ a = 1, b }, ...args) {}
6
7// ... and neither does this:
8const foo = ({ a: a = 1 }) => {};

In fact, there are 23 syntax improvements for function parameters in ES2017, and only one of them is broken in ES Modules-supporting browsers. It seems unfortunate to transpile all those great features down to ES5 just for one browser!

This plugin takes a different approach than we've historically taken with JavaScript: it transpiles the broken syntax to the closest non-broken modern syntax. In the above case, here's what is generated to fix all ES Modules-supporting browsers:

input:

1const foo = ({ a = 1 }, b = 2, ...args) => [a,b,args];

output:

1const foo = ({ a: a = 1 }, b = 2, ...args) => [a,b,args];

That output works in all ES Modules-supporting browsers, and is only 59 bytes minified & gzipped.

Compare this to @babel/preset-env's targets.esmodules output (147 bytes minified & gzipped):

1const foo = function foo(_ref, b) {
2 let { a = 1 } = _ref;
3
4 if (b === void 0) { b = 2; }
5
6 for (
7   var _len = arguments.length,
8     args = new Array(_len > 2 ? _len - 2 : 0),
9     _key = 2;  _key < _len; _key++
10 ) {
11   args[_key - 2] = arguments[_key];
12 }
13
14 return [a, b, args];
15};

The result is improved bundle size and performance, while supporting the same browsers.

Important: Minification

The output generated by this preset includes workarounds for Safari 10, however minifiers like Terser sometimes remove these workarounds. In order to avoid shipping broken code, it's important to tell Terser to preserve the workarounds, which can be done via the safari10 option.

It's also generally the case that minifiers are configured to output ES5 by default, so you'll want to change the output syntax to ES2017.

With Terser's Node API:

1terser.minify({
2  ecma: 2017,
3  safari10: true
4})

With Terser CLI:

1terser --ecma 2017 --safari10 ...

With terser-webpack-plugin:

1module.exports = {
2  optimization: {
3    minimizer: [
4      new TerserPlugin({
5        terserOptions: {
6          ecma: 2017,
7          safari10: true
8        }
9      })
10    ]
11  }
12};

All of the above configurations also apply to uglify-es. UglifyJS (2.x and prior) does not support modern JavaScript, so it cannot be used in conjunction with this preset.

Empty State

No vulnerabilities found.

10

Dangerous-Workflow

Determines if the project's GitHub Action workflows avoid dangerous patterns.

10

Binary-Artifacts

Determines if the project has generated executable (binary) artifacts in the source repository.

10

License

Determines if the project has defined a license.

4

Code-Review

Determines if the project requires human code review before pull requests (aka merge requests) are merged.

0

Token-Permissions

Determines if the project's workflows follow the principle of least privilege.

0

CII-Best-Practices

Determines if the project has an OpenSSF (formerly CII) Best Practices Badge.

0

Maintained

Determines if the project is "actively maintained".

0

Pinned-Dependencies

Determines if the project has declared and pinned the dependencies of its build process.

0

Fuzzing

Determines if the project uses fuzzing.

0

Branch-Protection

Determines if the default and release branches are protected with GitHub's branch protection settings.

0

Security-Policy

Determines if the project has published a security policy.

0

SAST

Determines if the project uses static code analysis.

0

Vulnerabilities

Determines if the project has open, known unfixed vulnerabilities.

Reason

98 existing vulnerabilities detected

Details

Warn: Project is vulnerable to: GHSA-968p-4wvh-cqc8
Warn: Project is vulnerable to: GHSA-67hx-6x53-jw92
Warn: Project is vulnerable to: GHSA-6chw-6frg-f759
Warn: Project is vulnerable to: GHSA-v88g-cgmw-v5xw
Warn: Project is vulnerable to: GHSA-93q8-gq69-wqmw
Warn: Project is vulnerable to: GHSA-fwr7-v2mv-hh25
Warn: Project is vulnerable to: GHSA-qwcr-r2fm-qrc7
Warn: Project is vulnerable to: GHSA-v6h2-p8h4-qcjw
Warn: Project is vulnerable to: GHSA-grv7-fg5c-xmjg
Warn: Project is vulnerable to: GHSA-x9w5-v3q2-3rhw
Warn: Project is vulnerable to: GHSA-pxg6-pf52-xh8x
Warn: Project is vulnerable to: GHSA-3xgq-45jj-v275
Warn: Project is vulnerable to: GHSA-gxpj-cx7g-858c
Warn: Project is vulnerable to: GHSA-w573-4hg7-7wgq
Warn: Project is vulnerable to: GHSA-vh7m-p724-62c2
Warn: Project is vulnerable to: GHSA-r9p9-mrjm-926w
Warn: Project is vulnerable to: GHSA-434g-2637-qmqr
Warn: Project is vulnerable to: GHSA-49q7-c7j4-3p7m
Warn: Project is vulnerable to: GHSA-977x-g7h5-7qgw
Warn: Project is vulnerable to: GHSA-f7q4-pwc6-w24p
Warn: Project is vulnerable to: GHSA-fc9h-whq2-v747
Warn: Project is vulnerable to: GHSA-vjh7-7g9h-fjfh
Warn: Project is vulnerable to: GHSA-j4f2-536g-r55m
Warn: Project is vulnerable to: GHSA-r7qp-cfhv-p84w
Warn: Project is vulnerable to: GHSA-74fj-2j2h-c42q
Warn: Project is vulnerable to: GHSA-pw2r-vq6v-hr8c
Warn: Project is vulnerable to: GHSA-jchw-25xp-jwwc
Warn: Project is vulnerable to: GHSA-cxjh-pqwp-8mfp
Warn: Project is vulnerable to: GHSA-8r6j-v8pm-fqw3
Warn: Project is vulnerable to: MAL-2023-462
Warn: Project is vulnerable to: GHSA-ww39-953v-wcq6
Warn: Project is vulnerable to: GHSA-2cf5-4w76-r9qv
Warn: Project is vulnerable to: GHSA-3cqr-58rm-57f8
Warn: Project is vulnerable to: GHSA-g9r4-xpmj-mj65
Warn: Project is vulnerable to: GHSA-q2c6-c6pm-g3gh
Warn: Project is vulnerable to: GHSA-765h-qjxv-5f44
Warn: Project is vulnerable to: GHSA-f2jv-r9rf-7988
Warn: Project is vulnerable to: GHSA-43f8-2h32-f4cj
Warn: Project is vulnerable to: GHSA-6x33-pw7p-hmpq
Warn: Project is vulnerable to: GHSA-qqgx-2p2h-9c37
Warn: Project is vulnerable to: GHSA-896r-f27r-55mw
Warn: Project is vulnerable to: GHSA-9c47-m6qq-7p4h
Warn: Project is vulnerable to: GHSA-jg8v-48h5-wgxg
Warn: Project is vulnerable to: GHSA-36fh-84j7-cv5h
Warn: Project is vulnerable to: GHSA-7x7c-qm48-pq9c
Warn: Project is vulnerable to: GHSA-rc3x-jf5g-xvc5
Warn: Project is vulnerable to: GHSA-6c8f-qphg-qjgp
Warn: Project is vulnerable to: GHSA-76p3-8jx3-jpfq
Warn: Project is vulnerable to: GHSA-3rfm-jhwj-7488
Warn: Project is vulnerable to: GHSA-hhq3-ff78-jv3g
Warn: Project is vulnerable to: GHSA-p6mc-m468-83gw
Warn: Project is vulnerable to: GHSA-29mw-wpgm-hmr9
Warn: Project is vulnerable to: GHSA-35jh-r3h4-6jhm
Warn: Project is vulnerable to: GHSA-82v2-mx6x-wq7q
Warn: Project is vulnerable to: GHSA-952p-6rrq-rcjv
Warn: Project is vulnerable to: GHSA-f8q6-p94x-37v3
Warn: Project is vulnerable to: GHSA-vh95-rmgr-6w4m
Warn: Project is vulnerable to: GHSA-xvch-5gv4-984h
Warn: Project is vulnerable to: GHSA-5fw9-fq32-wv5p
Warn: Project is vulnerable to: GHSA-6fx8-h7jm-663j
Warn: Project is vulnerable to: GHSA-hj48-42vr-x3v9
Warn: Project is vulnerable to: GHSA-h7cp-r72f-jxh6
Warn: Project is vulnerable to: GHSA-v62p-rq8g-8h59
Warn: Project is vulnerable to: GHSA-hrpp-h998-j3pp
Warn: Project is vulnerable to: GHSA-p8p7-x288-28g6
Warn: Project is vulnerable to: GHSA-gcx4-mw62-g8wm
Warn: Project is vulnerable to: GHSA-c2qf-rxjj-qqgw
Warn: Project is vulnerable to: GHSA-h9rv-jmmf-4pgx
Warn: Project is vulnerable to: GHSA-hxcc-f52p-wc94
Warn: Project is vulnerable to: GHSA-g4rg-993r-mgx7
Warn: Project is vulnerable to: GHSA-fxwf-4rqh-v8g3
Warn: Project is vulnerable to: GHSA-25hc-qcg6-38wj
Warn: Project is vulnerable to: GHSA-xfhh-g9f5-x4m4
Warn: Project is vulnerable to: GHSA-qm95-pgcg-qqfq
Warn: Project is vulnerable to: GHSA-cqmj-92xf-r6r9
Warn: Project is vulnerable to: GHSA-vx3p-948g-6vhq
Warn: Project is vulnerable to: GHSA-3jfq-g458-7qm9
Warn: Project is vulnerable to: GHSA-r628-mhmh-qjhw
Warn: Project is vulnerable to: GHSA-9r2w-394v-53qc
Warn: Project is vulnerable to: GHSA-5955-9wpr-37jh
Warn: Project is vulnerable to: GHSA-qq89-hq3f-393p
Warn: Project is vulnerable to: GHSA-f5x3-32g6-xq36
Warn: Project is vulnerable to: GHSA-4wf5-vphf-c2xc
Warn: Project is vulnerable to: GHSA-jgrx-mgxx-jf9v
Warn: Project is vulnerable to: GHSA-72xf-g2v4-qvf3
Warn: Project is vulnerable to: GHSA-884p-74jh-xrg2
Warn: Project is vulnerable to: GHSA-j7fq-p9q7-5wfv
Warn: Project is vulnerable to: GHSA-7p7h-4mm5-852v
Warn: Project is vulnerable to: GHSA-mgfv-m47x-4wqp
Warn: Project is vulnerable to: GHSA-wr3j-pwj9-hqq6
Warn: Project is vulnerable to: GHSA-j8xg-fqg3-53r7
Warn: Project is vulnerable to: GHSA-3h5v-q93c-6h6q
Warn: Project is vulnerable to: GHSA-6fc8-4gx4-v693
Warn: Project is vulnerable to: GHSA-776f-qx25-q3cc
Warn: Project is vulnerable to: GHSA-72mh-269x-7mh5
Warn: Project is vulnerable to: GHSA-h4j5-c7cj-74xg
Warn: Project is vulnerable to: GHSA-c4w7-xm78-47vh
Warn: Project is vulnerable to: GHSA-p9pc-299p-vxgp

Score

2.9

/10

Last Scanned on 2025-07-07

The Open Source Security Foundation is a cross-industry collaboration to improve the security of open source software (OSS). The Scorecard provides security health metrics for open source projects.