foo.pegjs

foo = '1'

package.json

{
  "name": "repro",
  "version": "0.0.0",
  "scripts": {
    "build": "peggy --dts foo.pegjs -o foo.js"
  },
  "dependencies": {
    "peggy": "github:peggyjs/peggy#pull/538/head"
  }
}