Registry / http-networking / rollup-plugin-esm-import-to-url

rollup-plugin-esm-import-to-url

library2.1.0jsnpmunverified

A Rollup plugin that transforms bare import specifiers (e.g., 'lit-element') into absolute URLs for ES module output. Suitable for CDN loading or micro-frontends. Current version 2.1.0. Release pattern is ad-hoc. Differentiators: integrates with Rollup's resolve pipeline, ensures bare imports are replaced only when mapped, and throws if specifiers are also listed in Rollup's external option.

http-networking web-framework

npm install rollup-plugin-esm-import-to-url

github ↗package ↗

INSTALL

IMPORT

SIG · ROLLUP-PLUGIN-ESM-

rollup-plugin-esm-import-to-url

http-networkingjavascriptv2.1.0

Install

—

Import

—

Disk

—

Pass rate

0/ 6

Env Coverage0 / 6

glibc

18–22

musl

18–22

Install & Compatibility

Where this runs

tested against v? · npm install

Install × environment matrix

Each cell = how many times install + import succeeded across repeated harness runs. Partial = flaky.
glibc = Debian/Ubuntu slim · musl = Alpine Linux

musl

node 18–223 runs

build_error

glibc

node 18–223 runs

build_error

Code

Verified usage

Verified import paths — ran on the pinned version, not inferred.

default

✓ import esmImportToUrl from 'rollup-plugin-esm-import-to-url'

✗ const esmImportToUrl = require('rollup-plugin-esm-import-to-url')

Package exports a default export. CommonJS require would not work for v2+ as it's ESM-only.

esmImportToUrl

✓ import esmImportToUrl from 'rollup-plugin-esm-import-to-url'

✗ import { esmImportToUrl } from 'rollup-plugin-esm-import-to-url'

Default export, not named. Named import will result in undefined.

Rollup plugins array entry

✓ esmImportToUrl({ imports: { 'pkg': 'https://cdn.example.com/pkg.js' } })

✗ esmImportToUrl({ 'pkg': 'https://cdn.example.com/pkg.js' })

Options must be wrapped in object with `imports` key; incorrect to pass direct property mapping.

Configures Rollup to replace bare import 'lit-element' with a CDN URL in the ESM output bundle.

// rollup.config.js import esmImportToUrl from 'rollup-plugin-esm-import-to-url'; export default { input: 'src/main.js', plugins: [ esmImportToUrl({ imports: { 'lit-element': 'https://cdn.jsdelivr.net/npm/lit-element@2.4.0/lit-element.js', }, }), ], output: { file: 'dist/bundle.js', format: 'esm', }, };

Debug

Known issues

breakingIf a bare import specifier is also listed in Rollup's `external` option, the plugin will throw an error.

fix

Remove the specifier from `external` or ensure it is not duplicated.

affects: >=1.0.0

breakingOutput must be formatted as 'esm' (ES modules). Other formats like 'cjs' or 'iife' will cause incorrect behavior or errors.

fix

Set `output.format` to 'esm'.

affects: >=1.0.0

deprecatedRequires Node.js version >=10. Older versions may fail.

fix

Upgrade Node.js to v10 or later.

affects: >=2.0.0

gotchaPlugin only transforms bare import specifiers that are mapped in the `imports` option; other bare imports remain unchanged and may fail at runtime.

fix

Ensure all external bare imports are explicitly mapped.

affects: >=1.0.0

Errors

Common errors & fixes

Error: The following imports are both in the import map and in Rollup's external list: ["lit-element"]

Duplicate declaration: import specifier appears in both `external` and plugin's `imports`.

fix

Remove the specifier from Rollup's `external` option and rely on the plugin.

Error: [plugin:esm-import-to-url] Could not resolve import 'lit-element'

Bare import specifier is not mapped in `imports` option and not otherwise resolved.

fix

Add the specifier to `imports` in plugin options.

ReferenceError: require is not defined (when using CommonJS require)

Package is ESM-only; using `require()` in Node.js <13 or without ESM support fails.

fix

Use `import` syntax or ensure Node.js version supports ESM.

Upgrade

Version history

2.1.0latest on npm

Audit

Dependencies

rolluprequiredThis is a Rollup plugin; Rollup is a peer dependency.

Agent activity

4 hits · last 30 days

node

Resources

githubhttps://github.com/trygve-lie/rollup-plugin-esm-import-to-url ↗

packagehttps://www.npmjs.com/package/rollup-plugin-esm-import-to-url ↗