Webpack 2 + System.import: default export has to be read with .default

[Jessidhia]

Snippet demonstrating the issue:

// test.js
export default class Test {}

// index.js (with proper runtime available)
System.import('./test').then(Test => {
  new Test() // error! must use new Test.default()
})

The following code gets generated in webpack's chunk containing test.js:

/* harmony default export */ exports["default"] = Test;

This behaves differently from when you use import Test from './test', as when you use such a static import you can then call new Test() instead of having to call new Test.default().

I also considered this might be an issue with babel transforms, but as it is getting emitted as a /* harmony default export */, I don't believe babel is transforming the export. I am using the es2015-webpack preset to preserve harmony imports/exports.

Not sure if this a webpack 2 bug or just a documentation issue.

[Jessidhia]

Hm, I just noticed that this basically has the same behavior as import * as Test from './test'. In this case, I would still have to access Test.default to get at the default export.

Thus, I suppose this is only a documentation (or expectation) issue.

[helloyou2012]

@Kovensky , I use this plugin to solve this problem: https://github.com/59naga/babel-plugin-add-module-exports

[sokra]

Not sure if this a webpack 2 bug or just a documentation issue.

Thus, I suppose this is only a documentation (or expectation) issue.

Yep, working as intended.

[sokra]

@Kovensky , I use this plugin to solve this problem: https://github.com/59naga/babel-plugin-add-module-exports

I don't recommend this. babel had good reasons for no longer doing so.

[hkrutzer]

Take a look at https://medium.com/@kentcdodds/misunderstanding-es6-modules-upgrading-babel-tears-and-a-solution-ad2d5ab93ce0

[pksjce]

This issue was moved to webpack/webpack.js.org#122