Enchanting using /give do not work in 1.13-pre1, 18w22c and 18w21b, in 18w20c it works.

For example putting this command in command block or in player gives a bow without any enchantments(It should give protection I)

/give @p bow{ench:[

]} 1

While in 1.12.2 it works

give @p bow 1 0 {ench:[

]}