webpack-oxc-parsing-adapter

A drop-in adapter that replaces webpack's default acorn parser with oxc-parser — a high-performance Rust-based JavaScript/TypeScript parser.

How it works

Webpack exposes a module.parser.javascript.parse hook that lets you supply a custom parse function. This adapter wraps oxc-parser and translates its output into the ESTree-compatible shape that webpack expects, including:

• Lazy loc resolution via binary search over line-start offsets (avoids computing locations for every node up front)
• Semicolon position tracking for ASI (automatic semicolon insertion) detection
• Transparent proxying of nested AST nodes so that location data is only computed on demand

Requirements

• Node.js >=18.0.0
• webpack ^5.0.0

Installation

npm install webpack-oxc-parsing-adapter

webpack is a peer dependency. If it is not already installed:

npm install --save-dev webpack

Usage

In your webpack.config.js, import the adapter and pass it to module.parser.javascript.parse:

const oxcParse = require("webpack-oxc-parsing-adapter");

/** @type {import("webpack").Configuration} */
module.exports = {
  module: {
    parser: {
      javascript: {
        parse: oxcParse,
      },
    },
  },
};

That's all — webpack will now use oxc-parser for every JavaScript module in the build.

Example

A minimal working project lives in the example/ directory.

example/
  src/
    index.js   # entry point
    math.js
    greet.js
  webpack.config.js
  package.json

To run it:

cd example
npm install
npm run build

The compiled output is written to example/dist/.

API

The adapter exports a single function with the signature expected by webpack:

function oxcParse(sourceCode: string, options: ParseOptions): ParseResult

| Parameter | Type | Description | |--------------|----------------|------------------------------------------| | sourceCode | string | The JavaScript/TypeScript source to parse | | options | ParseOptions | Webpack parse options (sourceType, etc.) |

Returns a ParseResult object with ast, comments, and semicolons.

License

MIT @ Even Stensberg