Opportunity to save kb and improve performances

1. The framework plugins don’t need the HTML API, so we could provide a second bundle that gets rid of the global mutation observer and everything that comes with it. From my tests we could save about 5kb of script with this, plus one less mutation observer that could improve performances especially in a JS app scenario.

SimpleBar with HTML API: 949 lines SimpleBar without HTML API: 819 lines

1. resizeObserver is now supported on most modern browser so we should probably not include the polyfill by default anymore https://caniuse.com/#feat=resizeobserver Edit: actually iOS Safari still doesn’t include it so we might keep it anyway.

2. We should group DOM read and write (like what fastDOM is doing) to reduce layout trashing

[Grsmto]

There is!

I released a new beta version: simplebar@6.0.0-beta.1. I didn’t advertise it cause I need to write changelog and everything but I’ll do a sum up here, as most suggestions in this issue were applied:

• Remove resize-observer-polyfill entirely from the dependencies. I didn’t find an easy solution to “have it by default” and let advanced users remove it if needed, so let’s just get rid of it. I totally agree that it should be lightweight by default.
• Move to lodash-es instead of importing the lodash/function-name version since we were very likely importing twice the same helper functions (thanks @hc-codersatlas)
• As suggested in my initial comment, the HTML API is now separated. That saves us a few kb.

[re-thc]

For saving kb why not optimize lodash too? See: https://github.com/fkhadra/react-on-screen/issues/55 for example