Dynamically load jQuery on the desktop

[blowery]

PR #27778 ended up pulling jQuery into the vendor~build bundle due to a conditional require in lib/load-script. Get it back out of build by dynamically loading jQuery on desktop. Webpack will still see this require on the normal web build as a require.ensure and build a chunk for it, which we'll probably never load.

[matticbot]

Test live: https://calypso.live/?branch=try/asyncload-jquery-on-desktop

[ghost]

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[vindl]

LGTM!

[blowery]

this might have some adverse impact on the sdk? tests seem ok... looks like no one had written a test for code that uses asyncRequire before. @dmsnell @ockham any thoughts on this?

[blowery]

Thanks @vindl! @jsnajdr @dmsnell @ockham @sirreal I changed the babel config as part of this to always include the asyncRequire / AsyncLoad transform. It was previously not being run on test code, which prevented us from testing code that uses asyncRequire.

Does anyone know why we were restricting that transform before?

[dmsnell]

Does anyone know why we were restricting that transform before?

Not me but it seems like a reasonable assumption that it would be web-only since that's where the async constraint comes in.

I'm fine removing it - thanks for this update!

[sirreal]

Does anyone know why we were restricting that transform before?

I'd speculate, like @dmsnell, that this was because the Desktop app supposes it has access to the entire app immediately and doesn't need to request bundles over the network as the app loads. code-splitting is disabled for Desktop:

wp-calypso/config/desktop.json

Line 24 in 3da9faf

"code-splitting": false,

With that in mind, it doesn't seem like the AsyncRequire transform should be harmful in any way, I'd expect webpack to just treat the require.ensure( module ) that are generated the same as require( module ).