rollup-plugin-purs

1.0.38 verified Mon Apr 27 auth: no javascript maintenance

Rollup plugin to bundle PureScript modules into optimized JavaScript bundles. Current stable version is 1.0.38. It integrates PureScript compilation output with Rollup, offering tree shaking and advanced optimizations like uncurrying, inlining, dead code elimination, and constant propagation. Compared to purs bundle or webpack, it produces smaller file sizes (e.g., 35.7 kB vs 65.2 kB for a sample app). Requires manual PureScript compilation beforehand (e.g., with pulp build). Releases are infrequent; last update was in 2017. Not actively maintained, but functional for existing projects.

Common errors

error Error: Cannot find module 'rollup-plugin-purs' ↓

cause The package is not installed or npm install failed.

fix

Run 'npm install rollup-plugin-purs --save-dev'.

error SyntaxError: Unexpected token 'export' — maybe you need to use CommonJS require? ↓

cause Using require() instead of import on an ESM-only package.

fix

Use 'import purs from "rollup-plugin-purs"' in an ES module context or set type:"module" in package.json.

error Error: The 'dest' option is deprecated. Use 'output.file' instead. ↓

cause Rollup version mismatch: dest was used in older Rollup config.

fix

Use output.file instead of dest, or use Rollup ^0.41.6 which supports dest.

Warnings

gotcha Plugin does not compile PureScript; you must run pulp build or purs compile first. ↓

fix Run 'pulp build -- --source-maps' or equivalent before running rollup.

gotcha Requires Rollup version ^0.41.6; incompatible with newer Rollup versions (>=1.0.0). ↓

fix Use an older Rollup version (e.g., 0.41.6) or consider alternatives.

gotcha assumePureVars optimization can break programs with impure FFI or unsafe functions. ↓

fix Set assumePureVars: false in options if using impure FFI.

gotcha debug: true may display warnings about dynamic exports, require, or module; can be suppressed with comment pragmas. ↓

fix Add // rollup-plugin-purs ignore dynamic exports comments in source files.

Install

npm install rollup-plugin-purs

yarn add rollup-plugin-purs

pnpm add rollup-plugin-purs

Imports

default
wrong
```
const purs = require('rollup-plugin-purs')
```
correct
```
import purs from 'rollup-plugin-purs'
```
The package is ESM-only; CommonJS require will fail. Use import syntax.
purs
wrong
```
import { purs } from 'rollup-plugin-purs'
```
correct
```
import purs from 'rollup-plugin-purs'
```
The plugin is exported as default, not named. Named import { purs } is incorrect.
Plugin
wrong
```
import { Plugin } from 'rollup-plugin-purs'
```
correct
```
import type { Plugin } from 'rollup'
```
TypeScript type for the plugin configuration is not exported by this package; use rollup's Plugin type.

Quickstart

Basic Rollup config to bundle PureScript output. Requires prior PureScript compilation with pulp build.

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

export default {
  input: 'src/Main.purs',
  output: {
    file: 'bundle.js',
    format: 'iife',
    sourcemap: true
  },
  plugins: [purs()]
};

// Build: run 'pulp build -- --source-maps' first, then 'rollup -c'