UMD Wrapper Intro Documentation

Documentation Is:

• Missing
• Needed
• Confusing
• Not Sure?

Please Explain in Detail...

I'm currently looking at:

https://github.com/rollup/rollup/blob/51e727c99bfc67a6bc46087c63950cec2a7fe12f/src/finalisers/umd.ts#L147-L153

And noticed that it is using an older UMD template. It appears the template was changed here:
https://github.com/umdjs/umd/pull/22

I came across this when I was comparing the output from @babel/plugin-transform-modules-umd vs Rollup and saw that they were different. Babel's plugin does use the newer syntax.

It is nice to see both Babel and Rollup supporting globalThis.

Your Proposal for Changes

This may be a non-issue since Rollup is the build tool, but umd.ts might benefit from a small comment explaining the reason why it does not use the version that puts AMD first, or at the very least noting that it is intentional.

Compared to other open issues, I see this as a low priority. I couldn't find an existing issue that seemed to fit, so I opened a new one.

Start with src/finalisers/umd.ts around lines 147-153 and compare the referenced UMD template change with Babel's UMD output. Check whether the existing wrapper choice is intentional; done means the rationale is clearly documented there if maintainers agree that clarification is needed.