As I’ve been playing with Nerves, I’ve been impressed by how simple it is to use. If you…

Mix won’t remove dependencies from your lock file unless you tell it to.

mix deps.clean --unused --unlock
mix deps.unlock dependency
mix deps.unlock --unused

These things are equivalent:

// 1
var sum = function(a, b) {
  return a + b
}// 2
var sum = (a, b) => {
  return a + b
}// 3
var sum = (a, b) => a + b