rollup-plugin-http-resolve

4.0.1-alpha.0 verified Sat Apr 25 auth: no javascript

A Rollup plugin that resolves imports via HTTP(S) URLs, enabling bundling of code from CDNs like esm.sh or unpkg. Current version 4.0.1-alpha.0 has irregular release cadence (last release ~2022). Key differentiator: it allows Rollup to fetch and bundle dependencies directly from HTTP sources, with optional caching and fallback to CDN resolution. Requires Node.js 14+. Written in TypeScript with built-in types.

Common errors

error Error [ERR_REQUIRE_ESM]: require() of ES Module not supported. ↓

cause Using CommonJS require() to load an ESM-only package.

fix

Use dynamic import: const { httpResolve } = await import('rollup-plugin-http-resolve');

error TypeError: httpResolve is not a function or does not provide a plugin. ↓

cause Incorrect import (default import instead of named import) or mismatched Rollup version.

fix

Use named import: import { httpResolve } from 'rollup-plugin-http-resolve';

Warnings

breaking Requires Rollup >=2.0; compatibility with Rollup 3.x is untested. ↓

fix Ensure Rollup version is >=2.0 and <4.0.0, or test with Rollup 3.x.

deprecated Version 4.0.1-alpha.0 is an alpha release and may have unstable APIs. ↓

fix Use 3.x stable versions if available, or pin to known working alpha.

gotcha ESM-only package; CommonJS require throws error. ↓

fix Use dynamic import() or convert project to ESM.

gotcha HTTP imports are not cached by default; may cause repeated network requests. ↓

fix Provide a cache Map in options to avoid redundant fetches.

Install

npm install rollup-plugin-http-resolve

yarn add rollup-plugin-http-resolve

pnpm add rollup-plugin-http-resolve

Imports

httpResolve

wrong

const httpResolve = require('rollup-plugin-http-resolve')

correct

import { httpResolve } from 'rollup-plugin-http-resolve'

ESM-only package; CommonJS require will fail. Use dynamic import() if needed.

HttpResolveOptions

wrong

import { HttpResolveOptions } from 'rollup-plugin-http-resolve'

correct

import type { HttpResolveOptions } from 'rollup-plugin-http-resolve'

Type-only import; do not use at runtime.

Quickstart

Shows basic usage: resolve a remote HTTP import with optional cache and CDN fallback.

import { httpResolve } from 'rollup-plugin-http-resolve';
import { rollup } from 'rollup';

async function bundle() {
  const bundle = await rollup({
    input: 'https://example.com/module.js',
    plugins: [
      httpResolve({
        cache: new Map(),
        fallback(id) {
          if (!id.startsWith('.')) {
            return `https://esm.sh/${id}`;
          }
        }
      })
    ]
  });
  const { output } = await bundle.generate({ format: 'es' });
  console.log(output[0].code);
}
bundle();