ES5 transpilation on typescript

[Banou26]

🐛 bug report

Parcel ignores engines.node and still transpile the code with babel

🎛 Configuration (.babelrc, package.json, cli command)

package.json

{
  "name": "parcel-node-babel",
  "version": "1.0.0",
  "main": "index.js",
  "license": "MIT",
  "dependencies": {
    "parcel-bundler": "^1.11.0"
  },
  "scripts": {
    "build": "parcel --target node src/index.ts",
    "start": "node dist/index.js"
  },
  "devDependencies": {
    "typescript": "^3.2.2"
  },
  "engines": {
    "node": ">= 8.0.0"
  }
}

🤔 Expected Behavior

Parcel respect engines.node for node just like it respect browserslist for the browser target

😯 Current Behavior

import JSPackager from 'parcel-bundler/src/packagers/JSPackager'
class Foo extends JSPackager{}
new Foo()

The source code is transpiled to ES5 which causes the Foo class to be transpiled to a function and throw Class constructor JSPackager cannot be invoked without 'new'

I think it's related to #839 but in their case, setting browserslist to "last 1 Chrome versions" fix the problem, but since in my case the target is node, browserlist is replaced by engines.node which doesn't work.

💻 Code Sample

https://github.com/Banou26/parcel-node-babel

🌍 Your Environment

Software	Version(s)
Parcel	1.11.3
Node	11.5.0
npm/Yarn
Operating System

[Banou26]

After some tests, it appears that the code is always transpiled to ES5 when the source is a typescript file , if the file is javascript, the code is properly transpiled using the browserslist and engines.node

[Banou26]

After some more tinkering i finally found the solution to prevent typescript from transpiling to es5
tsconfig.json

{
  "compilerOptions": {
    "target": "esnext"
  }
}

[ViktoriaShelestenko]

After some more tinkering i finally found the solution to prevent typescript from transpiling to es5
tsconfig.json

{
  "compilerOptions": {
    "target": "esnext"
  }
}

THANK YOU! You helped a lot!

[mischnic]

We should consider applying browserslist or engines.node to typescript (maybe only if that value isn't already set in tsconfig.json).

[mischnic]

See #860