Variety of usages in Ch4, Ch5, Ch6, Ch7, Ch9, and the fp-helpers.js use slice() with no arguments, to make a shallow copy of an array. The more preferred approach should be with ES6 [...x] instead of x.slice().
Care needs to be taken in this update, as it's widespread enough to affect layout.
Variety of usages in Ch4, Ch5, Ch6, Ch7, Ch9, and the fp-helpers.js use
slice()with no arguments, to make a shallow copy of an array. The more preferred approach should be with ES6[...x]instead ofx.slice().Care needs to be taken in this update, as it's widespread enough to affect layout.