let callbacks = []; export default { props: { callback: (value) => callbacks.push(value), val1: '1', val2: '2' }, before_test() { callbacks = []; }, async test({ assert, component, target }) { assert.equal(callbacks.length, 2); assert.equal(JSON.stringify(callbacks), '["1","2"]'); component.val1 = '3'; assert.equal(callbacks.length, 3); assert.equal(JSON.stringify(callbacks), '["1","2","1"]'); component.val1 = '4'; assert.equal(callbacks.length, 4); assert.equal(JSON.stringify(callbacks), '["1","2","1","1"]'); component.val2 = '5'; assert.equal(callbacks.length, 5); assert.equal(JSON.stringify(callbacks), '["1","2","1","1","2"]'); } };