rollup-swc-preserve-directives

0.7.0 verified Mon Apr 27 auth: no javascript

Rollup plugin that uses SWC to preserve directives such as shebang and string directives (e.g., 'use strict', 'use asm') in bundled output. Version 0.7.0 is the latest stable; updated on demand. It integrates with Rollup build pipeline to ensure important code-level annotations are not stripped during minification or transformation, unlike naive bundlers. Differentiates itself by being SWC-based (fast, Rust-powered) and designed specifically for directive preservation.

Common errors

error Error: Cannot find module '@swc/core' ↓

cause @swc/core is not installed or not in node_modules.

fix

Run npm install @swc/core in your project directory.

error TypeError: swcPreserveDirectives is not a function ↓

cause Using named import instead of default import.

fix

Use import swcPreserveDirectives from 'rollup-swc-preserve-directives' (no curly braces).

Warnings

breaking SWC version mismatch can cause parse errors or unexpected behavior. ↓

fix Use @swc/core version compatible with the SWC version used by this plugin; check package.json peerDependencies.

deprecated Rollup <4 support may be dropped in future versions. ↓

fix Upgrade Rollup to ^4.0.0 if encountering issues, or pin to older plugin version.

gotcha Plugin only works with Rollup's JavaScript plugins; if using TypeScript, ensure SWC is configured separately for type stripping. ↓

fix Use @rollup/plugin-typescript or @rollup/plugin-sucrase for TS before this plugin.

Install

npm install rollup-swc-preserve-directives

yarn add rollup-swc-preserve-directives

pnpm add rollup-swc-preserve-directives

Imports

default

wrong

const swcPreserveDirectives = require('rollup-swc-preserve-directives')

correct

import swcPreserveDirectives from 'rollup-swc-preserve-directives'

ESM default export; CJS require() works but not recommended for consistency.

swcPreserveDirectives

wrong

import { swcPreserveDirectives } from 'rollup-swc-preserve-directives'

correct

import swcPreserveDirectives from 'rollup-swc-preserve-directives'

Avoid named import; only default export is provided.

type definitions
```
import type { RollupSwcPreserveDirectivesOptions } from 'rollup-swc-preserve-directives'
```
Types are shipped but not exported directly; use module augmentation if needed.

Quickstart

Demonstrates basic usage of rollup-swc-preserve-directives plugin in a Rollup config to preserve directives during bundling.

import swcPreserveDirectives from 'rollup-swc-preserve-directives';
import { defineConfig } from 'rollup';

export default defineConfig({
  input: 'src/index.js',
  output: {
    dir: 'dist',
    format: 'esm'
  },
  plugins: [
    swcPreserveDirectives()
  ]
});