Feature: Check against total file size

[manniL]

Do you want to request a feature or report a bug?

A feature

What is the current behavior?

Bundlesize currently checks if each file is below the threshold.

What is the expected behavior?

With a flag set (e.g. checkAgainstTotal), bundlesize should sum up the size of all (selected) files and check it against a threshold.

If this is a feature request, what is motivation or use case for changing the behavior?

In times of code splitting, it can happen that you have 100 files <3kb, but in the end, this still means that the app is large.

[siddharthkp]

Thanks for taking the time!

bundlesize tries to shy away from total size because the performance of a page depends a lot on the way the individual bundles load (prefetch/lazy-load/on-demand, etc.)

We've had discussions around total in the past and it doesn't make sense to drive confidence from a metric that is biased/nuanced.

One strategy that has worked for teams using bundlesize is to measure initial bundles and chunks with different thresholds:

"bundlesize": [
  { "path": "./dist/feature-*.js", "maxSize": "30 kB"},
  { "path": "./dist/chunk-*.js", "maxSize": "5 kB" }
]

Let me know if that's a satisfactory answer, I can talk about this in more detail if you'd like

[manniL]

@siddharthkp Thanks for that fast answer! I understand now why the measurement of individual files makes more sense than measure the total file size. ☺️

[vanslly]

Total size makes sense for setting a library size budget for an npm package you publish, but where you don't want to bundle the package and leave bundling to consumers. Sure the consuming application could cherry-pick & tree-shake the code paths unused, but as a library author it still makes sense to measure & set budgets for the code published in an npm package.

To achieve this I'm resorting to rollup to generate a bundle for me, and then I run bundlesize over this bundle. This bundle is simply for bundlesize, so I discard this bundle once done.

[siddharthkp]

@vanslly that's great implementation, thanks for leaving it here