perf(build): Optimize terser minifier config for CDN bundles#19852
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HazAT wants to merge 2 commits intoautoresearch/browser-bundle-size-2026-03-17from
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perf(build): Optimize terser minifier config for CDN bundles#19852HazAT wants to merge 2 commits intoautoresearch/browser-bundle-size-2026-03-17from
HazAT wants to merge 2 commits intoautoresearch/browser-bundle-size-2026-03-17from
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size-limit report 📦
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node-overhead report 🧳Note: This is a synthetic benchmark with a minimal express app and does not necessarily reflect the real-world performance impact in an application.
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Semver Impact of This PR🟢 Patch (bug fixes) 📋 Changelog PreviewThis is how your changes will appear in the changelog. New Features ✨Deps
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Enable additional terser compress and mangle options that safely reduce
the size of CDN bundle .min.js files:
- compress.passes: 5 (multi-pass finds more dead code)
- compress.ecma: 2020 (allows modern syntax: nullish coalescing, optional chaining)
- compress.toplevel: true (better variable inlining within the IIFE)
- compress.unsafe_arrows: true (function → arrow where this is unused, ~1.3KB raw)
- compress.unsafe_methods: true ({ m: function(){} } → { m(){} })
- compress.unsafe_comps/unsafe_math/pure_getters: safe algebraic opts
- mangle.toplevel: true (mangle top-level names inside IIFE scope)
Also adds 'sW' to the mangle reserved list (used by a follow-up change that
shortens the sentryWrapped function name for frame stripping).
These options only affect CDN .min.js bundles, not npm ESM/CJS output.
Saves ~300 bytes gzipped on the base browser bundle.
Co-Authored-By: Claude claude@anthropic.com
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This prevents the terser mangle option from mangling the 'Sentry' name, and avoids a terser bug where our top-level 'var Sentry=' gets stripped.
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Summary
Enable additional terser compress and mangle options that safely reduce CDN
.min.jsbundle sizes. Saves ~300 bytes gzipped on the base browser bundle.Changes
compress.passes: 5compress.ecma: 2020compress.toplevel: truecompress.unsafe_arrows: truefunctionto=>wherethisis unused (~1.3KB raw)compress.unsafe_methods: true{ m(){} }compress.unsafe_comps / unsafe_math / pure_gettersmangle.toplevel: trueThese options only affect CDN
.min.jsbundles, not npm ESM/CJS output. Theunsafe_*options are safe for our codebase because the CDN bundles run in browser contexts where the assumptions hold.Also pre-reserves
sWin the mangle list for a follow-up change.Part of #19833.
Co-Authored-By: Claude claude@anthropic.com