tsc-esm-fix

Make tsc-compiled es2020/esnext bundles compatible with esm/mjs requirements

Motivation

This workaround is aimed to bypass a pair of tsc and ts-jest issues right here and right now.

TS/issues/13422: tsc should add .js extensions for relative module paths.
ts-jest/issues/1174: import.meta is not allowed.

Hope one day this library will not be needed.

Features

Finds and replaces __dirname and __filename refs with import.meta.
Injects extensions to imports/re-exports statements.
- import {foo} from './foo' → import {foo} from './foo.js'
- import {baz} from 'external/baz' → import {baz} from 'external/baz.js'
- Pays attention to index files: import {bar} from './bar' → import {bar} from './bar/index.js'
Follows outDir found in tsconfig.json.
Changes file extensions if specified by opts.
Supports Windows-based runtimes.

Requirements

Node.js >= 14

Install

yarn add -D tsc-esm-fix

Usage

tsc-esm-fix [options]

import { fix } from 'tsc-esm-fix'
await fix({
  dirnameVar: true,
  filenameVar: true,
  ext: true
})

API

CLI

tsc-esm-fix [opts]

Option	Description	Default
`--tsconfig`	Path to project's ts-config(s)	`tsconfig.json`
`--target`	Entry points where compiled files are placed for modification	If not specified inherited from tsconfig.json compilerOptions.outDir
`--dirnameVar`	Replace `__dirname` usages with `import.meta`	true
`--filenameVar`	Replace `__filename` var references `import.meta`	true
`--ext`	Append extension to relative imports/re-exports	`.js`
`--cwd`	cwd	`process.cwd()`
`--out`	Output dir. Defaults to `cwd`, so files would be overwritten	`process.cwd()`
`--debug`	Prints debug notes

JS/TS

import { fix, IFixOptions } from 'tsc-esm-fix'

const fixOptions: IFixOptions = {
  tsconfig: 'tsconfig.build.json',
  dirnameVar: true,
  filenameVar: true,
  ext: true
}

await fix(fixOptions)

export interface IFixOptions {
  cwd: string
  out?: string,
  target?: string | string[]
  tsconfig: string | string[]
  dirnameVar: boolean
  filenameVar: boolean
  ext: boolean | string
}

Alternatives

https://github.com/mothepro/tsc-esm https://github.com/digital-loukoum/tsc-esm

License

MIT