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feat: improve module.exports bundle to ESM library #19776

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Merged
merged 1 commit into from
Aug 11, 2025
Merged

feat: improve module.exports bundle to ESM library #19776

merged 1 commit into from
Aug 11, 2025
+52 −2

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hai-x
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@hai-x hai-x commented Aug 9, 2025

What kind of change does this PR introduce?

If we have CommonJsSelfReferenceDependency, we will generate default export statement in ESM library output.

// CommonJsSelfReferenceDependency
module.exports = {}

// CommonJsSelfReferenceDependency
this.foo = {}

// CommonJsSelfReferenceDependency
Object.defineProperty(module.export, "foo", ...)

Partial support about 💎Nice CommonJS modules are converted to ESM

Did you add tests for your changes?

Yes

Does this PR introduce a breaking change?

No

What needs to be documented once your changes are merged?

Nothing

@codspeed-hq CodSpeed HQ
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codspeed-hq bot commented Aug 9, 2025 •
edited
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CodSpeed Performance Report

Merging #19776 will degrade performances by 91.44%

Comparing cjs-to-esm (39455bd) with main (67379fe)

Summary

⚡ 2 improvements
❌ 3 regressions
✅ 37 untouched benchmarks

⚠️ Please fix the performance issues or acknowledge them on CodSpeed.

Benchmarks breakdown

Benchmark BASE HEAD Change
❌ benchmark "devtool-source-map", scenario '{"name":"mode-development-rebuild","mode":"development","watch":true}' 90.2 ms 130.6 ms -30.93%
❌ benchmark "future-defaults", scenario '{"name":"mode-development-rebuild","mode":"development","watch":true}' 14.7 ms 52 ms -71.77%
❌ benchmark "lodash", scenario '{"name":"mode-development-rebuild","mode":"development","watch":true}' 71.8 ms 838.7 ms -91.44%
⚡ benchmark "many-modules-commonjs", scenario '{"name":"mode-development-rebuild","mode":"development","watch":true}' 121.6 ms 96.5 ms +25.96%
⚡ benchmark "many-modules-esm", scenario '{"name":"mode-development-rebuild","mode":"development","watch":true}' 127.5 ms 99.3 ms +28.36%

@alexander-akait alexander-akait merged commit e3c48f5 into main Aug 11, 2025
42 of 44 checks passed
@alexander-akait alexander-akait deleted the cjs-to-esm branch August 11, 2025 11:55
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@hai-x @alexander-akait