Try restricting what we transpile to the last couple chromes.

[blowery]

Only doing this to see if there's a significant size difference.

[matticbot]

Test live: https://calypso.live/?branch=try/split-builds-by-ua

[blowery]

Interesting. Pretty massive chunk movement: http://iscalypsofastyet.com/branch?branch=try/split-builds-by-ua

vendors~build drops by 2k
build drop by 14k
reader up 2K
...

[blowery]

Poking at the bundle analyzer, I was surprised that the core-js Promise and Map where still being pulled into vendors~build. Turns out this is coming from wpcom, which is built using babel and includes the babel-6 runtime itself...

[dmsnell]

Turns out this is coming from wpcom, which is built using babel and includes the babel-6 runtime itself...

Should we try and internalize/transpile wpcom.js the way we do notifications-panel? I don't think it's code is incompatible with ours

[blowery]

Should we try and internalize/transpile wpcom.js the way we do notifications-panel?

I'd rather not, as it makes us a special consumer and changes the expectation of what the library is. I think ideally we redo wpcom.js to explicitly state that clients must polyfill Promise / Set / Map / whatever if they want things to work and publish is as es5 code. It's the same road that React is taking.

[dmsnell]

I think ideally we redo wpcom.js to explicitly state that clients must polyfill Promise / Set / Map / whatever if they want things to work and publish is as es5 code.

Hm. I saw Babel in use for tests but I didn't see any mechanism which loads it for the build. Maybe I'm overlooking something in the code itself? I checked the Makefile, webpack.config.js, and package.json files…

[blowery]

@dmsnell that is curious! It looks like the magic is done by n8-make:
https://github.com/Automattic/wpcom.js/blob/master/Makefile#L6
https://github.com/TooTallNate/n8-make#extending-the-makefile
https://github.com/TooTallNate/n8-make/blob/master/n8-make-js#L8

[dmsnell]

magic is done by n8-make

ha! I missed that

[jsnajdr]

Nice article about the future of transpiling your dependencies: https://babeljs.io/blog/2018/06/26/on-consuming-and-publishing-es2015+-packages

The article mentions a nice trick how to publish two bundles at once and let the browser choose the one it's capable of executing: two <script> tags, one <script type="module"> and one <script nomodule>.

[alisterscott]

This branch needs a rebase. Are we continuing with this PR?

[blowery]

Yeah, once #26531 lands we can revist this.

[dmsnell]

Yeah, once #26531 lands we can revist this.

Also @blowery - I forgot about this issue - just this week we were discussing the possibility of moving wpcom.js into Calypso's source tree itself. I think that if we do that and use the SDK to build the published npm version we should be able to reduce our bundle size and preserve the external behaviors from that package.

[sirreal]

#26531 landed. Also see #26624

[blowery]

Closing in favor of #30420