Resolve Imports

This is a Rollup plugin that resolves import specifiers in input files:

import packageSubdir from 'my-package/something'
import packageDefault from 'my-package'
import relativeImport from './relative'

To fully ESM-compatible specifiers including file extensions, deferring to package.json exports field for imported modules:

// package.json exports: ./* -> ./*/index.js
import packageSubdir from 'my-package/something/index.js'
// package entry is OK
import packageDefault from 'my-package'
// resolve relative import
import relativeImport from './relative.js'

This plugin was developed to turn TypeScript's module: esnext into valid ESM. By default, TS emits relative imports like import stuff from './myModule', which must be resolved at build-time in order for it to execute in an ESM context.

Further reading

Issues

• https://github.com/microsoft/TypeScript/issues/42151
• https://github.com/microsoft/TypeScript/issues/16577
• https://github.com/microsoft/TypeScript/issues/33588

Comments

• https://github.com/microsoft/TypeScript/issues/15479#issuecomment-300240856
• https://github.com/microsoft/TypeScript/issues/16577#issuecomment-754941937
• https://github.com/microsoft/TypeScript/issues/26722#issuecomment-580975983