Add sideEffects=false to package.json

[denisx]

Type of Change

feature

Description

Add side effects to package.json, help bundlers cut unused code with treeshake. Good for esm, modules, named imports.

ESM is how files and imports are organized, Side effects is how a bundler can remove obviously unused data from an assembly. Only both make maximum effect.

rollup https://rollupjs.org/configuration-options/#treeshake-modulesideeffects
webpack https://webpack.js.org/guides/tree-shaking/#mark-the-file-as-side-effect-free
esbuild https://esbuild.github.io/plugins/#on-resolve-arguments

[faisalman]

Hi, thanks for the PR.

Quick question though, since UAParser attaches itself to the global window object & jQuery (if applicable) when initialized:

ua-parser-js/src/main/ua-parser.js

Line 1418 in 3d41647

window.UAParser = UAParser;

Would that count as a side effect?

[denisx]

It can make effect, it can make no effect. But builders can do its best with this key.

[kokozztt]

Mm