"import *" seems to be broken

[drcmda]

input:

import * as THREE from 'three'

export default function(name) {
  return THREE[name]
}

output (compilation_level: SIMPLE_OPTIMIZATIONS):

import * as THREE from 'three'
export default function (a) {
  return THREE[a]
}

👍

input:

import * as THREE from 'three'

export default function(name) {
  const o = new THREE.Group()
  return THREE[name] + o.id
}

output:

import { Group } from 'three'
export default function (a) {
  let b = new Group()
  return THREE[a] + b.id
}

😕 it took away the THREE import for some reason, return THREE[a] is now invalid.

[blickly]

Can you give a more complete repro case? This single file as given seems like it wouldn't compile since it's got an unfulfilled import:
https://closure-compiler.appspot.com/home#code%3Dimport%2520*%2520as%2520THREE%2520from%2520'three'%250A%250Aexport%2520default%2520function(name)%2520%257B%250A%2520%2520const%2520o%2520%253D%2520new%2520THREE.Group()%250A%2520%2520return%2520THREE%255Bname%255D%2520%252B%2520o.id%250A%257D

[drcmda]

@blickly i am using @ampproject/rollup-plugin-closure-compiler which pulls in google-closure-compiler and sets up node resolution and esm, so that it understands imports. the online compiler seems to be set to BROWSER.

the project is here: https://github.com/react-spring/react-three-fiber/tree/v5

and this is our config: https://github.com/react-spring/react-three-fiber/blob/v5/rollup.config.js#L73-L78

it prepends the missing import statement as plain text right now as a workaround

[blickly]

OK, thanks.

In general, Closure Compiler assumes that the ESM code will all be internal to the application being compiled and that it can removed in the optimized bundle. Thus it doesn't (yet) support outputting optimized code that still contains ESM syntax.

So I would suspect that it's something else in the setup that is producing the ESM imports around the optimized code. If you can dig into the actual substep that is calling Closure Compiler you might uncover more.