let unsubscribeCalled = false; const fakeStore = val => ({ subscribe: cb => { cb(val); return { unsubscribe: () => { unsubscribeCalled = true; } }; } }); export default { props: { foo: fakeStore(1) }, html: `

1

`, async test({ assert, component, target }) { component.foo = fakeStore(5); assert.htmlEqual(target.innerHTML, '

5

'); assert.ok(unsubscribeCalled); } };