Function expect

build-system/tasks/e2e/expect.js:29–37

* @param {*} actual * @param {string=} opt_message * @return {!Chai.Assertion}

(actual, opt_message)

 * @return {!Chai.Assertion}
 */
function expect(actual, opt_message) {
  if (!installed) {
    installed = true;
    // See https://www.chaijs.com/guide/helpers/ for details on implementation
    chai.use(installWrappers);
  }

  return chai.expect(actual, opt_message);
}

/** @enum {string} */
const ChaiType = {