Make powerplug fully treeshakable

[TrySound]

The latest a couple of bytes (rollup: 365, webpack: 1356) are just left
imports. They can't be treeshaked by default because itself may have
side effects. But we may be sure that everything else will not exist if
powerplug will be used by unused library.

[renatorib]

Oh, it's great! Powerplug diet 😄

[renatorib]

Ops, I forgot to ask if I could merge. Is there any problem?

[TrySound]

No problem :)

[renatorib]

BTW, what's the magic here? Was the reduction of the bundle just because of static removal?

[TrySound]

Yes. It's just treeshaked size reduction.

[renatorib]

Nice!

[jedwards1211]

They can't be treeshaked by default because itself may have
side effects. But we may be sure that everything else will not exist if
powerplug will be used by unused library.

I don't quite understand what you mean here, what does "itself" refer to? What side effects does importing from react-powerplug have?

[jedwards1211]

I'm also trying to understand how releasing a single file has benefits for tree shaking over releasing the original structure of the js modules. I would have thought the only point to releasing a rollup bundle is in the UMD case where it puts ReactPowerPlug on the global scope as a side effect?

[TrySound]

Flat bundle gives more control over treeshakability. I just can test it with size-snapshot.

Here's proof https://github.com/renatorib/react-powerplug/blob/master/.size-snapshot.json#L17-L23

I meant that rollup doesn't remove external imports because they may have potential side effects. That's why I introduced import_statements line in size snapshot which shows how big piece of code is just imports.

I don't quite understand what you mean here, what does "itself" refer to? What side effects does importing from react-powerplug have?

[TrySound]

Having structure introduces one important problem: internal stuff is available for user who can catch breaking change because of using undocumented api.