async-wait.01.js

async-wait.01.js

// ES7
async function foo() {
  await bar();
}

// ES5 complied
let foo = (() => {
  var _ref = _asyncToGenerator(function*() {
    yield bar();
  });

  return function foo() {
    return _ref.apply(this, arguments);
  };
})();

function _asyncToGenerator(fn) {
  return function() {
    var gen = fn.apply(this, arguments);
    return new Promise(function(resolve, reject) {
      function step(key, arg) {
        try {
          var info = gen[key](arg);
          var value = info.value;
        } catch (error) {
          reject(error);
          return;
        }
        if (info.done) {
          resolve(value);
        } else {
          return Promise.resolve(value).then(
            function(value) {
              step("next", value);
            },
            function(err) {
              step("throw", err);
            }
          );
        }
      }
      return step("next");
    });
  };
}