Downgrade rollup to 1.27.9

[nicolo-ribaudo]

Q	A
Fixed Issues?	Fixes #11534
Patch: Bug Fix?
Major: Breaking Change?
Minor: New Feature?
Tests Added + Pass?	Yes
Documentation PR Link
Any Dependency Changes?
License	MIT

This is a partial revert of #11233. Due to a bug in rollup's tree-shaking logic, @babel/standalone didn't contain some necessary code. (#11534 (comment))

We cannot upgrade to Rollup 2 yet because it requires Node.js 10.

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[babel-bot]

Build successful! You can test your changes in the REPL here: https://babeljs.io/repl/build/21995/

[JLHwung]

This issue can be reproducible on https://rollupjs.org/repl/?version=2.0.0 (copy paste the regjsparser source), do we have an upstream issue to track?

Updates: I have created an upstream issue: rollup/rollup#3543.

[hzoo]

We cannot upgrade to Rollup 2 yet because it requires Node.js 10.
Are we building standalone on every node version? Maybe we could just do it on latest?

[nicolo-ribaudo]

We need to build standalone to test it 🤷
We can try to update rollup in the next-8-dev branch.

[JLHwung]

@nicolo-ribaudo Currently @babel/standalone is only tested on latest node. If we interpret node >= 6 support as:

Babel can work on Node.js 6 and it is tested on Node.js 6, but Babel may not be built on node >= 6.

Then we can consider upgrading rollup and ESLint, etc. but leave jest stay on v24 to run tests only. I believe none of core team members are developing babel on node.js 6, and this change should be ideally invisible to users.

[nicolo-ribaudo]

@JLHwung It seems to be fixed when using https://rollupjs.org/repl/?version=2.8.2

Regarding the dependencies updates: I think we use rollup to build the parser even on Node.js 6.

[3cp]

Suggest to have a look at https://github.com/zeit/ncc

I was troubled by various rollup issues (especially break nodejs v14) before, moved to ncc with zero config, never want to go back.

[nicolo-ribaudo]

It lists "Only supports Node.js programs as input / output" as a design goal, and our output code must run on browsers 🤷

[3cp]

It generates commonjs code. As long as you don't use nodejs api, there is no reason the code cannot run on browser. I got few projects using ncc to generate runnable code in both browser and nodejs.

[3cp]

Example here
https://github.com/buttonwoodcx/bcx-validation/blob/55a17d6a10ab29c45fa0bf2dd37f1532f7159260/package.json#L31-L32

ncc doesn't support output to stdout, so there are two steps in my build.

1. ncc to pack all files into one js.
2. babel to transpile the bundle to es5 for IE11.