Remove IE polyfills and special casing

[aduh95]

IE users would need to include abortcontroller-polyfill, math-log2, and url-polyfill from npm.

[Murderlon]

Can we document a list of all the polyfills required for IE somewhere? README or in the docs. I think it would save a lot of figuring out for people that do still need to support it.

[kvz]

Can we document a list of all the polyfills required for IE somewhere? README or in the docs. I think it would save a lot of figuring out for people that do still need to support it.

We should have a 1.0->2.0 migration guide (separate, or inlined with the announcement post), that lists all of these. I think it also makes sense to mirror the required polyfills to the general docs after that yes. It's never to soon to start tracking them in a central place indeed, wherever we end up copying it. Perhaps, the 2.0 branch can already contain a WIP post, and we keep a bullet list of these. Each PR that introduces new requirements bundles with it addition(s) to that list. By the time we're ready all that's left to do is cleanup the language and decide where else to publish.

[aduh95]

PR update:

• documentation: ready for reviews
• CDN bundles change:
  • uppy.js contains no polyfills, and contains modern-ish JS syntax.
  • uppy.ie.js contains all the polyfills, and is transpilled to ES5 – the name could be improved I think.
• No E2E tests in IE anymore.
• I've updated the E2E test platforms to use latest versions of the targeted browsers.
• Some test suite now requires Node.js 15+ because of AbortController.

E2E tests are failing in Safari now, not sure if it's a flakiness of the CI or a real issue.

[Murderlon]

I think this all looks good but maybe @goto-bus-stop has an opinion on the bundling stuff.

[goto-bus-stop]

uppy.ie.js contains all the polyfills, and is transpilled to ES5 – the name could be improved I think.

would just "uppy.legacy.js" be good or would you prefer something more specific?

[aduh95]

uppy.legacy.js is probably clearer indeed.
Any thoughts on what I did here? https://github.com/transloadit/uppy/pull/2947/files#diff-3efa66d67b2e7884e464b3a83b970becde04ff04229de4af90187f8b4f4db596

[goto-bus-stop]

LGTM, I think in the final blog post it would be good to make it extra clear that we used to include these polyfills always, so it's not like you suddenly need 20KB of polyfills that you didn't before; it's just that we always included them in the past and we now let you omit them if you don't need them

[goto-bus-stop]

just two inconsequential things ^^