ES6导入/导出语法困难

Question

I currently have a directory structure as follows, where + denotes a folder:

+ middleware
  - index.js
  + tracking
    - index.js
    + googleAnalytics
      - index.js
      - logPageView.js
      - trackPanos.js
    + mixpanelAnalytics
      - index.js
      - trackUser.js
- index.js

The lowest level index.js files in the googleAnalytics and mixPanel directories look like this:

--/middleware/tracking/googleAnalytics/index.js
import {logPageView} from './logPageView';
import {trackSignup} from './trackSignup';
export const googleAnalyticsMiddleware = [logPageView, trackSignup];

--/middleware/tracking/googleAnalytics/index.js
import {trackPanos} from './trackPanos';
export const mixpanelAnalyticsMiddleware = [trackPanos];

For some reason I'm able to successfully import things by directly looking up the relevant file paths . Here is the ROOT index.js:

--/index.js

import {mixpanelAnalyticsMiddleware} from './middleware/tracking/mixpanelAnalytics';
import {googleAnalyticsMiddleware} from './middleware/tracking/googleAnalytics';

// This works! But notice how deep I have to dig.

Ideally I would want something like this:

// This does not work!

--/index.js
import * from './middleware';

--/middleware/index.js
export * from './tracking';

--/middleware/tracking/index.js
export * from './mixpanelAnalyticsMiddleware';
export * from './googleAnalyticsMiddleware';

Answer 1

You should use the import * as xxx syntax.

So, when you have

export const googleAnalyticsMiddleware = [logPageView, trackSignup];
export const mixpanelAnalyticsMiddleware = [trackPanos];

In the js file you are importing, then it would look like

import * as Middleware from './middleware/file/path';
// ...
Middleware.googleAnalyticsMiddleware.doSomething();
Middleware.mixpanelAnalyticsMiddleware.doSomething();