Missing ArrayBuffer Built-In

[paulroper]

Hey! Love the preset. We're working on a project with IE9 support and ran in to a little issue with one of our dependencies (the isEmpty function in Lodash) using ArrayBuffer which IE9 does not support. We're using babel-preset-env to require built-ins and it does not seem to be bringing in ArrayBuffer from corejs.

After taking a look at the source for babel-preset-env, we noticed that the ArrayBuffer built-in is commented out in built-in-features.js and is missing from built-ins.json:

https://github.com/babel/babel-preset-env/blob/master/data/built-in-features.js#L32
https://github.com/babel/babel-preset-env/blob/master/data/built-ins.json

Is there a reason why this line has been commented out?

We've worked around the problem by adding a:

import 'core-js/modules/es6.typed.array-buffer';

[existentialism]

@paulroper IIRC, early on @hzoo and I were looking for a clearer mapping for ArrayBuffer in the compat-table data and probably just forgot :)

Thanks for the report, I think it makes sense to include the polyfill via ArrayBuffer[Symbol.species] support.

[existentialism]

@paulroper v1.3.1 should include core-js arraybuffer properly, see this test:

https://github.com/babel/babel-preset-env/tree/master/test/fixtures/preset-options/use-builtins-ie-9

Thanks again for the report!

[paulroper]

Amazing, thank you for responding so quickly! We'll get that into our codebase as soon as we can