import test from 'ava' ; import { Headers } from 'node-fetch' ; import { mergeHeaders } from './util' ; ( global as any ) . Headers = Headers ; test ( 'mergeHeaders(a, b)' , ( t ) => { const a = mergeHeaders ( new Headers ( { foo : 'bar' } ) , { bar : 'baz' , } ) ; t . is ( a . get ( 'foo' ) , 'bar' ) ; t . is ( a . get ( 'bar' ) , 'baz' ) ; } ) ;