"use strict"; { // private variables are defined with `const` so they don't leak outside this block statement const IFRAME_DEFAULT_SIZE = "200"; const iframes = new WeakMap(); // helpers are defined with `var` so they are globally accessible var createMQL = async t => { const iframe = await createIFrame(t); const mql = iframe.contentWindow.matchMedia(`(max-width: ${IFRAME_DEFAULT_SIZE}px)`); assert_true(mql.matches, "MQL should match on newly created