Polyfill/Core-JS not Included with Versions 7+

The latest versions of this repo do not appear to include the core-js polyfill when configuring:

'ember-cli-babel': {
  includePolyfill: true
}

…in the ember-cli-build.js file.

Here’s a branch demonstrating the issue, with a failing test: https://github.com/spencer516/babel-issue/tree/babel-7

Here’s the same, but with version 6.16, with a passing test: https://github.com/spencer516/babel-issue/tree/babel-6

[ggayowsky]

@Frozenfire92 Here is my solution.

Install the cjs transform addon (https://github.com/rwjblue/ember-cli-cjs-transform):

ember install ember-cli-cjs-transform

Import the file in ember-cli-build.js:

    // ember-cli-build.js
    app.import('node_modules/core-js/fn/array/flat-map.js', {
        using: [{ transformation: 'cjs', as: 'flat-map-polyfill' }]
    });

In app.js, import the module (using the alias you defined)

    // app.js

    // TODO: Remove when flat-map & flat reach stage 4
    // https://github.com/tc39/proposal-flatMap
    import 'flat-map-polyfill';

[ggayowsky]

@rwjblue I don’t know who is the maintainer of this package, but my recommadation would be to close this issue as it is not a problem with ember-cli-babel, but a breaking change in babel 7 where by the polyfill file no longer includes polyfills for < Stage 4 proposals (as @Frozenfire92 mentioned above).

@spencer516 and the example he included is just that flatMap is not included with the polyfills file.

I have posted a work around / solution for including < stage 4 proposals that should help with the migration from ember-cli-babel 6.x.x to 7.x.x