Babel 6.0.20 Modules feature not work in IE8

问题:

I am trying to export a es6 module in header.js:

export default {
    setHeaderHighlight: function (index) {
        // do somethings
    }
};

And import it in index.js:

import header from "./header.js"

$(function () {
    header.setHeaderHighlight(0);
});

Then transformation comes out in index.bundle.js:

var _header = __webpack_require__(129);

var _header2 = _interopRequireDefault(_header);

function _interopRequireDefault(obj) {
    return obj && obj.__esModule ? obj : { default: obj }; // crash here
}

So here is the problem, ie8 will rise a Expected identifier Exception at { default: obj }, but everythings is ok >=ie9.

Is there something i can do with this?

回答1:

By default, Babel 6.x requires you to enable an explicit set of transformations. The standard es2015 preset converts ES6 to ES5, however IE8 is not ES5-compatible. In this case, if you look at the plugins list, you will see

• transform-es3-member-expression-literals
• transform-es3-property-literals

These will convert your properties to be compatible with IE8. Generally in Babel 6.x you'd do this by passing those names as part of your plugins array, alongside the presets array and install the transforms via

npm install --save-dev babel-plugin-transform-es3-member-expression-literals babel-plugin-transform-es3-property-literals

回答2:

I use webpack + es3ify-loader as workaround.

loaders: {
  {
    test: /\.jsx?$/,
    exclude: /node_modules/,
    loaders: ['es3ify', `babel?${JSON.stringify(babelQuery)}`],
  },
}

回答3:

I also have the problem, and I wrote a webpack plugin to resolve it. I didn't really know if there is a nicer way to handle it, but it works.

The module in node_modules also works well.