ie-babel-class

this code use babel translate to es5 and run in IE<=9,

class TestSuper {
    constructor() {
        console.log('TestSuper constructor');
    }
}

class Test extends TestSuper {
    constructor() {
        console.log('Test constructor');
        super();
    }
}

export default Test;

will course error:

Unable to get value of the property '***': object is null or undefined

use this as polyfill will fix it.

npm i ie-babel-class

then import is before any js.