import test from 'ava' ; import { empty , fromArray , size } from '../../src' ; test ( 'returns 0 for an empty set' , t => { t . is ( size ( empty ( ) ) , 0 ) ; } ) ; test ( 'returns the number of items in a set' , t => { t . is ( size ( fromArray ( [ 'A' , 'B' , 'C' ] ) ) , 3 ) ; } ) ;