Registry / web-framework / babel-plugin-mjsx

babel-plugin-mjsx

library4.1.1jsnpmunverified

Babel plugin for Mithril JSX precompilation, converting JSX into Mithril virtual DOM nodes (e.g., {tag: 'div', attrs: {}, children: []}). Current stable version is 4.1.1. The plugin has evolved through major versions, with v4.0.0 changing whitespace trimming behavior and v4.1.0 adding jsxCompliant (attribute casing) and warnDeprecatedHtml options. It is the primary JSX compiler for Mithril v2+ and precompilation yields performance benefits over runtime interpretation.

web-framework

npm install babel-plugin-mjsx

github ↗package ↗

INSTALL

IMPORT

SIG · BABEL-PLUGIN-MJSX

babel-plugin-mjsx

web-frameworkjavascriptv4.1.1

Install

—

Import

—

Disk

—

Pass rate

0/ 6

Env Coverage0 / 6

glibc

18–22

musl

18–22

Install & Compatibility

Where this runs

tested against v? · npm install

Install × environment matrix

Each cell = how many times install + import succeeded across repeated harness runs. Partial = flaky.
glibc = Debian/Ubuntu slim · musl = Alpine Linux

musl

node 18–226 runs

build_error

glibc

node 18–226 runs

build_error

Code

Verified usage

Verified import paths — ran on the pinned version, not inferred.

plugin

✓ plugins: ['mjsx']

✗ plugins: ['babel-plugin-mjsx']

Babel plugin names are automatic without 'babel-plugin-' prefix

jsxCompliant

✓ plugins: [['mjsx', { jsxCompliant: true }]]

✗ plugins: [['mjsx', { jsxCompliant: 'true' }]]

Option must be boolean, not string

warnDeprecatedHtml

✓ plugins: [['mjsx', { warnDeprecatedHtml: true }]]

✗ plugins: [['mjsx', { deprecated: true }]]

Explicit option name is 'warnDeprecatedHtml'

Demonstrates Babel configuration and JSX-to-Mithril precompilation output.

// .babelrc { "plugins": [ ["mjsx", { jsxCompliant: true, warnDeprecatedHtml: false }] ] } // Input: const view = () => ( <div className="container"> <Component foo="bar">Text</Component> </div> ); // Output (simplified): const view = () => ({ tag: 'div', attrs: { className: 'container' }, children: [ m.component(Component, { foo: 'bar' }, ['Text']) ] });

Debug

Known issues

breakingv4.0.0 changed whitespace trimming behavior to match v1.x; existing code may render differently if relying on whitespace.

fix

Update to v4.0.0+ and adjust templates if whitespace matters.

affects: <4.0.0

deprecatedv4.1.0 changed option name from 'deprecated' to 'warnDeprecatedHtml'. Using deprecated option name will be ignored.

fix

Use 'warnDeprecatedHtml' instead of 'deprecated'.

affects: >=4.1.0

gotchaPlugin name in Babel config must be 'mjsx', not 'babel-plugin-mjsx' or Babel will fail to find it.

fix

Use 'mjsx' as plugin name in .babelrc or programmatic config.

affects: >=3.0.0

gotchaThe plugin outputs Mithril v1-style m.component() for custom components; Mithril v2 uses m() directly. This may cause confusion.

fix

Ensure your Mithril version is compatible or manually adjust output.

affects: >=4.0.0

Errors

Common errors & fixes

Error: Cannot find module 'babel-plugin-mjsx'

Plugin name incorrectly prefixed with 'babel-plugin-' in config, but npm installed correctly.

fix

Use 'mjsx' in Babel config, not 'babel-plugin-mjsx'.

Unsupported option: deprecated

Using 'deprecated' option name after v4.1.0.

fix

Replace 'deprecated' with 'warnDeprecatedHtml'.

TypeError: Cannot read properties of null (reading 'tag')

JSX returning null or undefined, e.g., conditional rendering without fallback.

fix

Ensure JSX always returns a valid element or wrap conditionals with m() or fragment.

Upgrade

Version history

4.1.1latest on npm

Audit

Dependencies

@babel/corerequiredBabel plugin requires Babel core to function

Agent activity

19 hits · last 30 days

node

OpenAI (training)

Resources

githubhttps://github.com/Naddiseo/babel-plugin-mjsx ↗

packagehttps://www.npmjs.com/package/babel-plugin-mjsx ↗