mirror of
https://github.com/lancedikson/bowser
synced 2026-10-27 05:48:45 +00:00
7b144d8247
Found by a differential test of the packed candidate against the published
2.14.1 across Node 12-22, Bun, TypeScript 4.7-7.0, seven bundlers and a
real browser.
- bowser.mjs is now lowered to ES5 syntax (keeping `export`). Before the
exports map, webpack, Rollup and esbuild resolved `import 'bowser'` to
es5.js via the `browser` field; the ES2015 bowser.mjs broke esbuild
`--target=es5` and shipped classes into webpack ES5 builds. The ESM build
sets `minify: false` explicitly, because rolldown's default DCE-only pass
re-prints the chunk after renderChunk and restores shorthand properties.
- `"sideEffects": ["./bundled.js"]` lets esbuild, Vite and webpack 4 drop an
unused `import 'bowser'`; bundled.js stays listed so polyfill-only imports
are never tree-shaken away.
- `./package` export restores extensionless `require('bowser/package')`,
which resolved on 2.14.1.
- bundled.js imports `core-js/es` plus the timers, immediate and
DOM-collection web polyfills instead of `core-js/stable`, dropping URL,
URLSearchParams and queueMicrotask, which no released bundled.js ever
shipped: 176.9 kB -> 156.1 kB (56.6 -> 49.3 kB gzip).
Tests: bowser.mjs must parse as ES5 apart from its export; bundled.js must
install the @babel/polyfill surface 2.14.1 shipped (passes on 2.14.1's
bundled.js, fails on unpolyfilled es5.js); package smoke test covers
`bowser/package` and `sideEffects`.
26 lines
1.1 KiB
JavaScript
26 lines
1.1 KiB
JavaScript
/**
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* UMD entry point for `bundled.js` — same as `es5.js`, but with the polyfills
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* needed by the browser targets baked in.
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*
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* This is the core-js@3 equivalent of the deprecated `@babel/polyfill` that
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* this bundle used to be built from, which was: all of ECMAScript, the
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* `timers`, `immediate` and DOM-collection iterator web polyfills, and
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* `regenerator-runtime`. `@babel/preset-env`'s `useBuiltIns: 'entry'` rewrites
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* the `core-js/*` imports below into the modules the configured targets need.
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*
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* `core-js/es` rather than `core-js/stable`: `stable` is `es` plus every web
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* polyfill, and the extra ones — `URL`, `URLSearchParams`, `queueMicrotask` —
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* were never in any released `bundled.js`, yet cost ~20 kB (~7 kB gzipped).
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* `test/acceptance/test-es5-runtime.js` pins the `@babel/polyfill` surface.
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*
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* See `./es5.js` for why this only re-exports the default.
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*/
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import 'core-js/es';
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import 'core-js/web/dom-collections';
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import 'core-js/web/immediate';
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import 'core-js/web/timers';
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import 'regenerator-runtime/runtime';
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import Bowser from '../../src/bowser.js';
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export default Bowser;
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