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

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.