let fulfil; const thePromise = new Promise(f => { fulfil = f; }); const items = [{ title: 'a title', data: thePromise }]; export default { props: { items }, html: ` <p>a title: loading...</p> `, test({ assert, target }) { fulfil(42); return thePromise .then(() => { assert.htmlEqual(target.innerHTML, ` <p>a title: 42</p> `); }); } };