import '../iterablehelpers' ; import { concat , of , sequenceEqual } from 'ix/iterable' ; test ( 'Iterable#concat behavior' , ( ) => { const res = concat ( [ 1 , 2 , 3 ] , [ 4 , 5 ] ) ; expect ( sequenceEqual ( res , of ( 1 , 2 , 3 , 4 , 5 ) ) ) . toBeTruthy ( ) ; } ) ;