pub fn bundle_build(
  entry e: String,
  outfile o: String,
) -> promise.Promise(Result(Nil, String))

pub fn bundle_watch(
  entry e: String,
  outfile o: String,
) -> promise.Promise(Result(Nil, String))

pub fn copy_build(
  conf f: String,
  outfile o: String,
) -> promise.Promise(Result(Nil, String))

pub fn copy_watch(
  conf f: String,
  outfile o: String,
) -> promise.Promise(Result(Nil, String))

pub fn main() -> promise.Promise(Result(Nil, Nil))