rollup-plugin-jsy

1.9.4 verified Fri May 01 auth: no javascript

A Rollup plugin that transforms JSY (a JavaScript syntax extension/sugar) into standard JavaScript using @jsy-lang/jsy. Version 1.9.4 is current, with stable API. This plugin enables using JSY syntax in Rollup builds, supporting both ESM and CommonJS outputs. Key differentiator: it leverages JSY's concise syntax while integrating seamlessly with Rollup's plugin system, including source maps and watch mode. Alternatives like Babel require separate configuration; this plugin is purpose-built for JSY.

Common errors

error Error: Unexpected token (Note that you need plugins to import files that are not JavaScript) ↓

cause Input file has .jsy extension but Rollup does not recognize it; plugin not added or misconfigured.

fix

Add jsy plugin to rollup.config.js and ensure 'include' covers the file.

error TypeError: jsy is not a function ↓

cause Importing the module incorrectly (e.g., using require or wrong named import).

fix

Use import jsy from 'rollup-plugin-jsy' (default import) or const jsy = require('rollup-plugin-jsy').default.

error Error: Cannot find module '@jsy-lang/jsy' ↓

cause Missing peer dependency @jsy-lang/jsy.

fix

Install peer dependency: npm install @jsy-lang/jsy --save-dev (or yarn add).

Warnings

breaking Plugin output changed from object to string in version 1.0.0. ↓

fix Update to latest version (1.9.4) and ensure downstream code expects string output.

deprecated Option 'sourceMap' renamed to 'sourcemap' in v1.2.0. ↓

fix Use 'sourcemap' instead of 'sourceMap' in plugin options.

gotcha The plugin only processes files with .jsy extension by default; other extensions need explicit 'include'. ↓

fix Use jsy({ include: ['**/*.jsy', '**/*.mjs'] }) to include additional patterns.

breaking Dropped support for Node.js 10 and 12 in v1.5.0. ↓

fix Upgrade to Node.js >=14.

gotcha Must be placed before other syntax plugins (e.g., @rollup/plugin-babel) in Rollup plugins array. ↓

fix Order plugins as: [jsy(), babel()] to ensure JSY transforms first.

Install

npm install rollup-plugin-jsy

yarn add rollup-plugin-jsy

pnpm add rollup-plugin-jsy

Imports

default

wrong

const jsy = require('rollup-plugin-jsy')

correct

import jsy from 'rollup-plugin-jsy'

ESM-only package, CommonJS require is not supported.

jsy
wrong
```
import Jsy from 'rollup-plugin-jsy'
```
correct
```
import { jsy } from 'rollup-plugin-jsy'
```
The package exports a function as default; named export 'jsy' also available.
pluginOptions
wrong
```
import type { PluginOptions } from 'rollup-plugin-jsy'
```
correct
```
import jsy, { PluginOptions } from 'rollup-plugin-jsy'
```
PluginOptions is a value export (not just type) for runtime use; TypeScript may treat it as type.

Quickstart

Minimal Rollup configuration using the JSY plugin to compile .jsy files.

// rollup.config.js
import jsy from 'rollup-plugin-jsy';

export default {
  input: 'src/index.jsy',
  output: {
    file: 'dist/bundle.js',
    format: 'esm'
  },
  plugins: [
    jsy() // options: { include, exclude, sourceMap, etc. }
  ]
};