2.77.77 • Public • Published


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An extensible library to highlight (and comment) JSX syntax in the Monaco Editor using Babel. It exposes its AST after it does its magic, so you can add your own syntax-based or custom highlights.


monaco-jsx-highlighter demo

# with npm (assuming you are already using monaco-editor)
  npm i @babel/parser @babel/traverse monaco-jsx-highlighter
# with yarn (assuming you are already using monaco-editor)
  yarn add @babel/parser @babel/traverse monaco-jsx-highlighter


import monaco from 'monaco-editor';
import {parse} from "@babel/parser";
import traverse from "@babel/traverse";
import MonacoJSXHighlighter, {makeBabelParse} from 'monaco-jsx-highlighter';

// Minimal Babel setup for React JSX parsing:
const babelParse = code => parse(code, {
   sourceType: "module",
   plugins: ["jsx"]

// Instantiate the highlighter
const monacoJSXHighlighter = new MonacoJSXHighlighter(
   monaco, babelParse, traverse, getMonacoEditor()
// Activate highlighting (debounceTime default: 100ms)
// Activate JSX commenting
// Done =)

function getMonacoEditor(){
  return monaco.editor.create(
          document.getElementById("editor"), {
            value: 'const AB=<A x={d}><B>{"hello"}</B></A>;',
            language: 'javascript'

//use makeBabelParse if unsure of the config you need for TSX


New in v2

  • Adds makeBabelParse: babel's parse configuration for JSX/TSX (thanks @HaimCandiTech)
  • TS codebase migration start.
  • Reported defect fixes(dispose).

New in v1

  • Babel is now used directly instead of via JsCodeShift.
  • React fragment, spread child, spread attribute, and container expression highlighting.
  • highlightOnDidChangeModelContent(debounceTime) method debounces highlight updates.
  • Several defect repairs.

Breaking Changes

If you have used 0.x versions, you'll notice JsCodeShift has been replaced with Babel:

- import j from 'jscodeshift';
+ import {parse} from "@babel/parser";
+ import traverse from "@babel/traverse";

This only affects the constructor signature:

+ const babelParse = code => parse(code, {sourceType: "module", plugins: ["jsx"]});
 const monacoJSXHighlighter = new MonacoJSXHighlighter(
- j,
+ babelParse, traverse,

Also, monacoJSXHighlighter.highlightOnDidChangeModelContent method now has an optional debounce time as first parameter on its signature:

- afterHighlight: func,
+ debounceTime: number, afterHighlight: func,


It requires monaco-editor , @babel/parser and @babel/traverse, for convenience, they are listed as peer dependencies and passed by reference (so you can do lazy loading). Please install them before monaco-jsx-highlighter;


Install the package in your project directory with:


# with npm
 npm install @babel/parser
 npm install @babel/traverse
 npm install monaco-jsx-highlighter


# with yarn
 yarn add @babel/parser
 yarn add @babel/traverse
 yarn add monaco-jsx-highlighter

Replacing CSS classes with your own

import {JSXTypes} from 'monaco-jsx-highlighter';
// JSXTypes:JSX Syntax types and their CSS classnames.
// Customize the color font in JSX texts:  .myCustomCSS {color: red;}
JSXTypes.JSXText.options.inlineClassName = "myCustomCSS";

Overriding CSS classes

Take a look of the src/JSXColoringProvider.css file and override the CSS classes you need. Make sure to import your customization CSS files after you import monaco-jsx-highlighter.

Advanced Usage

After your have a Monaco JSX Highlighter instance, monacoJSXHighlighter:

const defaultOptions = {
  parser: 'babel', // for reference only, only babel is supported right now
  isHighlightGlyph: false, // if JSX elements should decorate the line number gutter
  iShowHover: false, // if JSX types should  tooltip with their type info
  isUseSeparateElementStyles: false, // if opening elements and closing elements have different styling
  isThrowJSXParseErrors: false, // Only JSX Syntax Errors are not thrown by default when parsing, true will throw like any other parsign error

const monacoJSXHighlighter = new MonacoJSXHighlighter(
   monaco, babelParse, traverse, monacoEditor, defaultOptions

The highlight activation method, monacoJSXHighlighter.highlightOnDidChangeModelContent(debounceTime: number, afterHighlight: func, ...) , accepts a callback among other parameters. The callback afterHighlight passes the AST used to highlight the code. Passing parameters and using the disposer function returned by the call are optional.

Note: The disposer is always called when the editor is disposed.

// Optional: Disable highlighting when needed (e.g. toggling, unmounting, pausing)
const highlighterDisposeFunc = monacoJSXHighlighter.
highlighterDisposeFunc(); // if you need to

// Internally the highlighter is triggering after each code change debounced
let tid = null;
let debounceTime = 100; // default
monacoEditor.onDidChangeModelContent(() => {
  tid = setTimeout(() => {

// You can do the higlighting directly at anytime
// or customize its behavior by adding custom highlighting after the JSX highlighting
const afterHighlight = (
        ast // the ast generate by  Babel
) => {
  //... your customization code, check Babel for more info about AST types
  //optional: array with the decorators created by the highlighter, push your decorator ids to this array

        afterHighlight, //default: ast=>ast
        onError, // default: error=>console.error(error)
        getAstPromise, // default:  parse(monacoEditor.getValue())
        onParseErrors, // default: error=>error

Additionally, you can add JSX commenting to your monaco editor with monacoJSXHighlighter.addJSXCommentCommand(): comments in JSX children will result in {/*...*/} instead of //.... It mimics the commenting behavior of the WebStorm IDE.

Follow this code to find out other perks:

// Optional: Disable JSX commenting when needed (e.g. toggling, unmounting, pausing)
const commentDisposeFunc = monacoJSXHighlighter.addJSXCommentCommand();
commentDisposeFunc(); // if you need to

Creating Monaco compatible ranges from Babel

import {configureLocToMonacoRange} from 'monaco-jsx-highlighter';
// locToMonacoRange: converts Babel locations to Monaco Ranges
const locToMonacoRange = configureLocToMonacoRange(monaco);
const monacoRange = locToMonacoRange(babelAstNode.loc);

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npm i monaco-jsx-highlighter

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  • luminaxster