Ruff WASM

⚠️ WARNING: This API is experimental and may change at any time

An extremely fast Python linter and code formatter, written in Rust.

This is a WASM version of the Ruff API which can be used to lint/format Python in a browser environment.

There are multiple versions for the different wasm-pack targets. See here for more info on targets.

Usage

This example uses the wasm-pack web target and is known to work with Vite.

import init, { Workspace, type Diagnostic, PositionEncoding } from "@astral-sh/ruff-wasm-web";

const exampleDocument = `print('hello'); print("world")`;

await init(); // Initializes WASM module

// These are default settings just to illustrate configuring Ruff
// Settings info: https://docs.astral.sh/ruff/settings
const workspace = new Workspace(
  {
    "line-length": 88,
    "indent-width": 4,
    format: {
      "indent-style": "space",
      "quote-style": "double",
    },
    lint: {
      select: ["E4", "E7", "E9", "F"],
    },
  },
  PositionEncoding.UTF16,
);

// Will contain 1 diagnostic code for E702: Multiple statements on one line
const diagnostics: Diagnostic[] = workspace.check(exampleDocument);

const formatted = workspace.format(exampleDocument);

Versioning

This crate is an internal component of Ruff. The Rust API exposed here is unstable and will have frequent breaking changes.

This version (0.15.20) is a component of Ruff 0.15.20. The source can be found here.

See Ruff's crate versioning policy for details on versioning.