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SideEffects false

See original GitHub issue

Re package.json with sideEffects = false, there are a bunch of /*@__PURE__*/ comments around the code that I think we can safely get rid of? would that be correct @marcofugaro ?

I can make a PR for it if so.

Issue Analytics

State:
Created 2 years ago
Comments:6 (3 by maintainers)

Top GitHub Comments

1reaction

marcofugarocommented, Apr 16, 2021

Not quite, sideEffects: false just tells the bundler that we don’t attach anything to the window or any other global scopes.

It’s up to the bundler to understand what to remove and what not to. From the webpack tree-shaking guide:

Terser actually tries to figure it out, but it doesn’t know for sure in many cases. This doesn’t mean that terser is not doing its job well because it can’t figure it out. It’s just too difficult to determine it reliably in a dynamic language like JavaScript.

We can actually test this now, the test-treeshake script is testing importing three.js like if it was a npm module:

https://github.com/mrdoob/three.js/blob/c9350382c50e549c0d2960041448ffe652bbbd9b/test/treeshake/index.js#L1

If you remove all /*@__PURE__*/ and run npm run build && npm run test-treeshake you can see the threeshaken bundle size actually increase.

0reactions

DefinitelyMaybecommented, Apr 16, 2021

thank you all

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