core-js duplicates installed

[tmcw]

documentation.js is huge on npm install, for a weird reason:

npm v2.15.9

npm install documentation

All of the red is duplicate installations of core-js

• 57MB: documentationjs without core-js
• 372MB: documentationjs with core-js

Each core-js module install is 1.85MB and even though they're all the same exact version, npm installs one copy for every single babel transform.

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Actions: I have no idea, this is bad.

[chadxz]

for comparison, here's npm 3.10.9

that is with 78ac0b0 checked out.

[tmcw]

Looks like we just need to say "no more npm v2" and go anything but npm v2, whether that's v3 or yarn.