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fix: mark asset module as side-effect-free when futureDefaults#20535

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alexander-akait merged 2 commits intomainfrom
asset-side-effects
Feb 25, 2026
Merged

fix: mark asset module as side-effect-free when futureDefaults#20535
alexander-akait merged 2 commits intomainfrom
asset-side-effects

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@hai-x
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@hai-x hai-x commented Feb 25, 2026

Summary

What kind of change does this PR introduce?

Fixes #20515.

Avoid breaking changes for existing user cases that bundle or copy assets via sth like import "./x.png". This behavior is now gated by futureDefaults, so asset modules are only marked as side-effect-free when it is enabled.

Did you add tests for your changes?

Existing

Does this PR introduce a breaking change?

No

If relevant, what needs to be documented once your changes are merged or what have you already documented?

No

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changeset-bot bot commented Feb 25, 2026

🦋 Changeset detected

Latest commit: ef79fb9

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 1 package
Name Type
webpack Patch

Not sure what this means? Click here to learn what changesets are.

Click here if you're a maintainer who wants to add another changeset to this PR

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github-actions bot commented Feb 25, 2026

This PR is packaged and the instant preview is available (4f5c0a8).

Install it locally:

  • npm
npm i -D webpack@https://pkg.pr.new/webpack@4f5c0a8
  • yarn
yarn add -D webpack@https://pkg.pr.new/webpack@4f5c0a8
  • pnpm
pnpm add -D webpack@https://pkg.pr.new/webpack@4f5c0a8

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codspeed-hq bot commented Feb 25, 2026

Merging this PR will improve performance by ×2.7

⚡ 6 improved benchmarks
✅ 138 untouched benchmarks

Performance Changes

Mode Benchmark BASE HEAD Efficiency
Memory benchmark "many-chunks-commonjs", scenario '{"name":"mode-production","mode":"production"}' 8.5 MB 6.9 MB +23.01%
Memory benchmark "react", scenario '{"name":"mode-development-rebuild","mode":"development","watch":true}' 865.2 KB 645.2 KB +34.09%
Memory benchmark "many-modules-esm", scenario '{"name":"mode-production","mode":"production"}' 11.1 MB 8.1 MB +36.42%
Memory benchmark "asset-modules-source", scenario '{"name":"mode-development-rebuild","mode":"development","watch":true}' 390.1 KB 266.3 KB +46.53%
Memory benchmark "context-esm", scenario '{"name":"mode-production","mode":"production"}' 9.8 MB 7.5 MB +30.58%
Memory benchmark "future-defaults", scenario '{"name":"mode-development-rebuild","mode":"development","watch":true}' 894.8 KB 332.7 KB ×2.7

Comparing asset-side-effects (ef79fb9) with main (87987ca)

Open in CodSpeed

@hai-x hai-x marked this pull request as ready for review February 25, 2026 08:48
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@alexander-akait alexander-akait merged commit 4f5c0a8 into main Feb 25, 2026
53 of 56 checks passed
@alexander-akait alexander-akait deleted the asset-side-effects branch February 25, 2026 14:06
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Side effect imports should make asset modules as not side effect free

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