gem-hunter

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.

• microsoft/TypeScript#42151
• microsoft/TypeScript#16577
• microsoft/TypeScript#33588

• microsoft/TypeScript#15479 (comment)
• microsoft/TypeScript#16577 (comment)
• microsoft/TypeScript#26722 (comment)