Bundle with browser-pack-flat plugin

[etpinard]

A nice benefit from removing all circular deps in #2429, browser-pack-flat now allows us to trim some bundle bits (especially in our minified bundle).

Here's what browser-pack-flat can trim:

that's about 10 gzip+minified kB per bundle. Not bad I think.

That said, using browser-pack-flat comes at a price 💰 , npm run build is not a bit slower and consumes a lot more memory. So I had to use run-series to reduce memory consumption and make npm run build succeed consistently. Note also, I thinking of only using browser-pack-flat during npm run build to not slow npm run watch and npm start.

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Referencing https://github.com/plotly/plotly-webpack/issues/2 that first discussed bundling with browser-pack-flat.

[alexcjohnson]

Seems like a clear win, and all the choices you made seem right. One question though: why did the raw sizes increase?

[etpinard]

One question though: why did the raw sizes increase?

Good question. I think it has to do with the long variable names browser-pack-flat uses to denote exported fields in the global scope (example here) brower-pack-flat seems to be more liberal on \n too. Uglifyjs can easily 🔪 those things hence to smaller minified bundles.

[alexcjohnson]

Also:

browser-pack-flat does some more things like rewriting top-level variables in modules in case there is another variable with the same name in another module

Those names probably start getting pretty long in our bundle.

Anyway anyone who cares about size will use the minified versions, and this is a clear win. 💃