Tests should be created for all current + future async effects ensuring that local variables function properly before and after their execution. For example:

test "teleport local variable persistence":
  set {localTest::EffTeleport} to random uuid
  set {_local} to {localTest::EffTeleport}
  spawn a creeper
  teleport last spawned entity to spawn of (world of last spawned entity)
  asse

To create characters from char code and to get char codes from characters

Current coverage is not bad (70+%) and in general and I don't want to embark on one of those 100%-coverage crusades. But I know there are parts of the interpreter that are undertested (and don't generally need a whole lot of tests) and it might be nice to get some quick wins in terms of coverage.