\n and \u in written books do not work

\n in written books not creating new line, giving the error below.

Data tag parsing failed: Invalid escape of 'n' at: {pages:["[\"\",{\"text\":\"one\n<--[HERE] This is an example below, works in versions 17w15a and lower. {code}

/give @p written_book 1 0 {pages:["[\"\",

]"],title:Test,author:Test}

This issue was reported in MC-116553 but not enough information was given.