import { StrictEqualityComparer } from "../../shared" ; import { IEqualityComparer } from "../../types" ; param source param value param comparer returns export const contains = async < TSource > ( source , value , comparer = StrictEqualityComparer ) : Promise < boolean > => { for await ( const item of source ) { if ( comparer ( value , item ) ) { return true ; } } return false ; } ;