我如何转换这个箭头函数？

Question

I cannot figure out how to convert this arrow function into IE compatible function. I really appreciate if someone could provide a resolution to this:

const store = window.WebChat.createStore({}, ({ dispatch }) => next => async action => {
                        if (action.type === 'DIRECT_LINE/POST_ACTIVITY') {
                            // Mocking data to be sent
                            const userId = 'xyz789';
                            const payloadUserContext = action.payload;

                            action = window.simpleUpdateIn(
                                action,
                                ['payload', 'activity', 'channelData'],
                                () => ({
                                    'personId': userId,
                                    'domain': $.urlParam('d'),
                                    'environment': window.location.host,
                                    'userContext': payloadUserContext
                                })
                            )
                        }
                        return next(action);
                    });

Answer 1

Just use https://babeljs.io/

var store = window.WebChat.createStore({}, function (_ref) {
      var dispatch = _ref.dispatch;
      return function (next) {
        return async function (action) {
          if (action.type === 'DIRECT_LINE/POST_ACTIVITY') {
            // Mocking data to be sent
            var userId = 'xyz789';
            var payloadUserContext = action.payload;
            action = window.simpleUpdateIn(action, ['payload', 'activity', 'channelData'], function () {
              return {
                'personId': userId,
                'domain': $.urlParam('d'),
                'environment': window.location.host,
                'userContext': payloadUserContext
              };
            });
          }

          return next(action);
        };
      };
    });

Answer 2

You can use this online babel transpiler https://babeljs.io/repl (a transpiler is used to convert code from one version to another, in this case we want to go from es6 to es5).

You can check for ES browser support here https://www.w3schools.com/js/js_versions.asp

---

EDIT:

Messing around with the web, I find out babel produces a result that you probably wouldn't want to use (at least for functions defined with async/await).

What you can do is transpile with babel, and whatever is left with async/await, change it up to .then and .catch.

For instance,

 const someAsyncRequest = () => new Promise((resolve) => { setTimeout(() => { resolve("Responding") }, 1000) }) const myAsyncFunction = async () => { console.log("Making request") const result = await someAsyncRequest() console.log(result) console.log("Done!") } function myIE9AsyncFunction() { console.log("Making request") someAsyncRequest() .then(function (result) { console.log(result) console.log("Done!") }) .catch(function (error) { console.log("What the... ", error) }) } myAsyncFunction() myIE9AsyncFunction()