Skip to content

refactor: build exports-presence guards from formula#21320

Merged
alexander-akait merged 1 commit into
mainfrom
refactor-exports-presence-guard
Jul 3, 2026
Merged

refactor: build exports-presence guards from formula#21320
alexander-akait merged 1 commit into
mainfrom
refactor-exports-presence-guard

Conversation

@hai-x

@hai-x hai-x commented Jul 1, 2026

Copy link
Copy Markdown
Member

Summary

What kind of change does this PR introduce?

The export-presence guard that suppresses "export not found" warnings for namespace accesses behind an "x" in ns check was backed by an eagerly-built Map<string, Set<string>>. This PR reworks it into a boolean formula built lazily
from the branch test (atoms are the "x" in ns dependencies), sharing the same tuple-formula machinery already used for dead-branch dependency guards.

It also recognizes guards it missed before: the else branch of a negated check (if (!("a" in ns)) {} else { ns.a }), a statically-falsy right operand ("a" in ns || 0), and "a" in ns ?? 0 — the last enabled by teaching the evaluator that in always yields a (non-nullish) boolean.

Did you add tests for your changes?

Yes — extended test/configCases/compiletime/exports-presence/module.js with the
else-branch, || 0, and ?? 0 guard cases.

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?

n/a

Use of AI

Yes

@changeset-bot

changeset-bot Bot commented Jul 1, 2026

Copy link
Copy Markdown

⚠️ No Changeset found

Latest commit: 1b66ad9

Merging this PR will not cause a version bump for any packages. If these changes should not result in a new version, you're good to go. If these changes should result in a version bump, you need to add a changeset.

This PR includes no changesets

When changesets are added to this PR, you'll see the packages that this PR includes changesets for and the associated semver types

Click here to learn what changesets are, and how to add one.

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

@github-actions

github-actions Bot commented Jul 1, 2026

Copy link
Copy Markdown
Contributor

This PR is packaged and the instant preview is available (cebd793).

Install it locally:

  • npm
npm i -D webpack@https://pkg.pr.new/webpack@cebd793
  • yarn
yarn add -D webpack@https://pkg.pr.new/webpack@cebd793
  • pnpm
pnpm add -D webpack@https://pkg.pr.new/webpack@cebd793

@codecov

codecov Bot commented Jul 1, 2026

Copy link
Copy Markdown

Codecov Report

❌ Patch coverage is 96.19048% with 4 lines in your changes missing coverage. Please review.
✅ Project coverage is 92.87%. Comparing base (3cb8578) to head (1b66ad9).
⚠️ Report is 8 commits behind head on main.

Files with missing lines Patch % Lines
lib/dependencies/HarmonyImportGuard.js 95.29% 4 Missing ⚠️
Additional details and impacted files
@@           Coverage Diff           @@
##             main   #21320   +/-   ##
=======================================
  Coverage   92.86%   92.87%           
=======================================
  Files         594      594           
  Lines       65210    65247   +37     
  Branches    18143    18164   +21     
=======================================
+ Hits        60559    60595   +36     
- Misses       4651     4652    +1     
Flag Coverage Δ
css-parsing 28.56% <9.52%> (-0.04%) ⬇️
html5lib 31.09% <9.52%> (-0.05%) ⬇️
integration 88.89% <96.19%> (+<0.01%) ⬆️
test262 45.55% <23.80%> (-0.01%) ⬇️
unit 43.02% <9.52%> (-0.05%) ⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

☔ View full report in Codecov by Harness.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:
  • ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.
  • 📦 JS Bundle Analysis: Save yourself from yourself by tracking and limiting bundle sizes in JS merges.

@codspeed-hq

codspeed-hq Bot commented Jul 1, 2026

Copy link
Copy Markdown

Merging this PR will improve performance by 21.58%

⚠️ Different runtime environments detected

Some benchmarks with significant performance changes were compared across different runtime environments,
which may affect the accuracy of the results.

Open the report in CodSpeed to investigate

⚡ 3 improved benchmarks
❌ 2 regressed benchmarks
✅ 139 untouched benchmarks

Warning

Please fix the performance issues or acknowledge them on CodSpeed.

Performance Changes

Mode Benchmark BASE HEAD Efficiency
Memory benchmark "wasm-modules-sync", scenario '{"name":"mode-development-rebuild","mode":"development","watch":true}' 253.4 KB 361.2 KB -29.84%
Memory benchmark "devtool-eval-source-map", scenario '{"name":"mode-production","mode":"production"}' 6.3 MB 8.1 MB -22.03%
Memory benchmark "asset-modules-inline", scenario '{"name":"mode-development-rebuild","mode":"development","watch":true}' 1,075.1 KB 380.8 KB ×2.8
Memory benchmark "context-esm", scenario '{"name":"mode-production","mode":"production"}' 10.2 MB 7.4 MB +38.61%
Memory benchmark "many-chunks-commonjs", scenario '{"name":"mode-production","mode":"production"}' 9.2 MB 7.4 MB +24.12%

Tip

Investigate this regression by commenting @codspeedbot fix this regression on this PR, or directly use the CodSpeed MCP with your agent.


Comparing refactor-exports-presence-guard (1b66ad9) with main (f84840f)

Open in CodSpeed

@alexander-akait

Copy link
Copy Markdown
Member

Looks like #21322 the same but just ignoring (not a good idea, but fix the problem), right?

@hai-x

hai-x commented Jul 1, 2026

Copy link
Copy Markdown
Member Author

@alexander-akait

Looks like #21322 the same

Do you mean the changes in this PR?

@alexander-akait

Copy link
Copy Markdown
Member

@hai-x wrong place, feel free to make ready to review and let’s rerun bun

@hai-x hai-x marked this pull request as ready for review July 2, 2026 16:28
@github-actions

github-actions Bot commented Jul 2, 2026

Copy link
Copy Markdown
Contributor

Types Coverage

Coverage after merging refactor-exports-presence-guard into main will be
99.36%
Coverage Report
FileStmtsBranchesFuncsLinesUncovered Lines
bin
   webpack.js98.77%100%100%98.77%91
examples
   build-common.js100%100%100%100%
   buildAll.js100%100%100%100%
   examples.js100%100%100%100%
   template-common.js98.21%100%100%98.21%72
examples/custom-javascript-parser
   test.filter.js100%100%100%100%
examples/custom-javascript-parser/internals
   acorn-parse.js100%100%100%100%
   meriyah-parse.js100%100%100%100%
   oxc-parse.js91.30%100%100%91.30%140, 142–143, 145, 147, 153–154, 161, 168, 90
examples/markdown
   webpack.config.mjs100%100%100%100%
examples/module-federation
   test.filter.js100%100%100%100%
examples/reexport-components
   test.filter.js100%100%100%100%
examples/typescript
   test.filter.js100%100%100%100%
examples/typescript-non-erasable
   test.filter.js50%100%100%50%5
examples/virtual-modules
   test.filter.js100%100%100%100%
examples/wasm-bindgen-esm
   test.filter.js100%100%100%100%
examples/wasm-complex
   test.filter.js100%100%100%100%
examples/wasm-emscripten
   test.filter.js100%100%100%100%
examples/wasm-simple
   test.filter.js100%100%100%100%
examples/wasm-simple-source-phase
   test.filter.js100%100%100%100%
lib
   APIPlugin.js100%100%100%100%
   AsyncDependenciesBlock.js100%100%100%100%
   AutomaticPrefetchPlugin.js100%100%100%100%
   BannerPlugin.js100%100%100%100%
   Cache.js98.21%100%100%98.21%101
   CacheFacade.js100%100%100%100%
   Chunk.js99.72%100%100%99.72%39
   ChunkGraph.js100%100%100%100%
   ChunkGroup.js100%100%100%100%
   ChunkTemplate.js100%100%100%100%
   CircularModulesPlugin.js98.81%100%100%98.81%136
   CleanPlugin.js99.12%100%100%99.12%207, 227
   CodeGenerationResults.js100%100%100%100%
   CompatibilityPlugin.js100%100%100%100%
   Compilation.js98.43%100%100%98.43%1641, 1960, 1967, 1975, 1997, 2000, 2939, 3418–3419, 3451, 4117, 4147, 4200–4201, 4205, 4210, 4226–4227, 4241–4242, 4247–4248, 4725, 4751, 526, 531, 5559, 5591, 5608, 5624, 5640, 5655, 5680–5681, 5683, 6011, 6016, 6022, 6025, 6037, 6039, 6043, 6059, 6074, 6106, 6160, 6184, 6298, 777–778
   Compiler.js99.56%100%100%99.56%1147–1148, 1156
   ConcatenationScope.js98.65%100%100%98.65%195
   ConditionalInitFragment.js100%100%100%100%
   ConstPlugin.js100%100%100%100%
   ContextExclusionPlugin.js100%100%100%100%
   ContextModule.js100%100%100%100%
   ContextModuleFactory.js97.40%100%100%97.40%258, 395, 418, 420, 424, 433–434
   ContextReplacementPlugin.js100%100%100%100%
   DefinePlugin.js98.99%100%100%98.99%172–173, 189, 208, 282
   DependenciesBlock.js100%100%100%100%
   Dependency.js98.51%100%100%98.51%479, 525
   DependencyTemplate.js100%100%100%100%
   DependencyTemplates.js100%100%100%100%
   DotenvPlugin.js98.41%100%100%98.41%378, 391–392
   DynamicEntryPlugin.js100%100%100%100%
   EntryOptionPlugin.js100%100%100%100%
   EntryPlugin.js100%100%100%100%
   Entrypoint.js100%100%100%100%
   EnvironmentPlugin.js97.14%100%100%97.14%49
   ErrorHelpers.js100%100%100%100%
   EvalDevToolModulePlugin.js100%100%100%100%
   EvalSourceMapDevToolPlugin.js100%100%100%100%
   ExportsInfo.js100%100%100%100%
   ExportsInfoApiPlugin.js100%100%100%100%
   ExternalModule.js98.55%100%100%98.55%1100, 1103, 502–506, 508, 654
   ExternalModuleFactoryPlugin.js100%100%100%100%
   ExternalsPlugin.js100%100%100%100%
   FileSystemInfo.js99.52%100%100%99.52%182, 2382–2383, 2386, 2397, 2408, 2419, 280, 3823, 3838, 3862
   FlagAllModulesAsUsedPlugin.js100%100%100%100%
   FlagDependencyExportsPlugin.js98.42%100%100%98.42%413, 422, 424, 428
   FlagDependencyUsagePlugin.js100%100%100%100%
   FlagEntryExportAsUsedPlugin.js100%100%100%100%
   Generator.js100%100%100%100%
   HotModuleReplacementPlugin.js100%100%100%100%
   HotUpdateChunk.js100%100%100%100%
   IgnorePlugin.js100%100%100%100%
   IgnoreWarningsPlugin.js100%100%100%100%
   InitFragment.js100%100%100%100%
   JavascriptMetaInfoPlugin.js100%100%100%100%
   LazyBarrel.js100%100%100%100%
   LibraryTemplatePlugin.js100%100%100%100%
   LoaderOptionsPlugin.js100%100%100%100%
   LoaderTargetPlugin.js100%100%100%100%
   MainTemplate.js100%100%100%100%
   ManifestPlugin.js100%100%100%100%
   Module.js98.50%100%100%98.50%1285, 1290, 1350, 1364, 1426, 1435
   ModuleFactory.js100%100%100%100%
   ModuleFilenameHelpers.js98.85%100%100%98.85%106, 108
   ModuleGraph.js99.73%100%100%99.73%1005
   ModuleGraphConnection.js100%100%100%100%
   ModuleInfoHeaderPlugin.js100%100%100%100%
   ModuleNotFoundError.js100%100%100%100%
   ModuleProfile.js100%100%100%100%
   ModuleSourceTypeConstants.js100%100%100%100%
   ModuleTemplate.js100%100%100%100%
   ModuleTypeConstants.js100%100%100%100%
   MultiCompiler.js99.69%100%100%99.69%661
   MultiStats.js100%100%100%100%
   MultiWatching.js100%100%100%100%
   NoEmitOnErrorsPlugin.js100%100%100%100%
   NodeStuffPlugin.js100%100%100%100%
   NormalModule.js97.89%100%100%97.89%1227, 1230, 1247, 1264, 1511, 1545, 1561, 1648, 2004, 2303, 2308–2318, 419, 423, 577
   NormalModuleFactory.js99.47%100%100%99.47%1083, 1392, 486, 498
   NormalModuleReplacementPlugin.js100%100%100%100%
   NullFactory.js100%100%100%100%
   OptimizationStages.js100%100%100%100%
   OptionsApply.js100%100%100%100%
   Parser.js100%100%100%100%
   PlatformPlugin.js100%100%100%100%
   PrefetchPlugin.js100%100%100%100%
   ProgressPlugin.js98.85%100%100%98.85%527–528, 533, 535, 599
   ProvidePlugin.js100%100%100%100%
   RawModule.js100%100%100%100%
   RecordIdsPlugin.js100%100%100%100%
   RequestShortener.js100%100%100%100%
   ResolverFactory.js100%100%100%100%
   RuntimeGlobals.js100%100%100%100%
   RuntimeModule.js100%100%100%100%
   RuntimePlugin.js100%100%100%100%
   RuntimeTemplate.js100%100%100%100%
   SelfModuleFactory.js100%100%100%100%
   SingleEntryPlugin.js100%100%100%100%
   SourceMapDevToolModuleOptionsPlugin.js100%100%100%100%
   SourceMapDevToolPlugin.js98.62%100%100%98.62%220, 224, 226, 419, 430, 889
   Stats.js100%100%100%100%
   Template.js100%100%100%100%
   TemplatedPathPlugin.js99.43%100%100%99.43%308–309
   UseStrictPlugin.js100%100%100%100%
   WarnCaseSensitiveModulesPlugin.js100%100%100%100%
   WarnDeprecatedOptionPlugin.js100%100%100%100%
   WarnNoModeSetPlugin.js100%100%100%100%
   WatchIgnorePlugin.js100%100%100%100%
   Watching.js100%100%100%100%
   WebpackError.js100%100%100%100%
   WebpackIsIncludedPlugin.js100%100%100%100%
   WebpackOptionsApply.js100%100%100%100%
   WebpackOptionsDefaulter.js100%100%100%100%
   buildChunkGraph.js99.87%100%100%99.87%371
   cli.js98.63%100%100%98.63%10, 119, 549, 581, 631, 905
   index.js99.72%100%100%99.72%184
   validateSchema.js94.67%100%100%94.67%100, 87, 89, 98
   webpack.js96.33%100%100%96.33%10, 198, 220, 222
lib/asset
   AssetBytesGenerator.js100%100%100%100%
   AssetBytesParser.js100%100%100%100%
   AssetGenerator.js100%100%100%100%
   AssetModule.js100%100%100%100%
   AssetModulesPlugin.js97.33%100%100%97.33%282, 306, 309, 36, 362, 41
   AssetParser.js100%100%100%100%
   AssetSourceGenerator.js100%100%100%100%
   AssetSourceParser.js100%100%100%100%
   RawDataUrlModule.js100%100%100%100%
lib/async-modules
   AsyncModuleHelpers.js100%100%100%100%
   AwaitDependenciesInitFragment.js100%100%100%100%
   InferAsyncModulesPlugin.js100%100%100%100%
lib/bun
   BunTargetPlugin.js100%100%100%100%
lib/cache
   AddBuildDependenciesPlugin.js100%100%100%100%
   AddManagedPathsPlugin.js100%100%100%100%
   IdleFileCachePlugin.js97.92%100%100%97.92%75, 87, 95
   MemoryCachePlugin.js95.83%100%100%95.83%33
   MemoryWithGcCachePlugin.js93.15%100%100%93.15%107, 114–115, 123, 90
   PackFileCacheStrategy.js96.40%100%100%96.40%1251, 1351, 1355, 1417, 628, 647, 657–659, 661, 677–678, 683, 686, 688, 693, 698, 723, 729, 763, 769, 775, 780, 791, 800, 805–806, 808, 825, 831–832, 834
   ResolverCachePlugin.js100%100%100%100%
   getLazyHashedEtag.js100%100%100%100%
   mergeEtags.js100%100%100%100%
lib/config
   browserslistTargetHandler.js100%100%100%100%
   defaults.js99.33%100%100%99.33%1468–1470, 1478, 274,

@alexander-akait alexander-akait merged commit cebd793 into main Jul 3, 2026
146 of 148 checks passed
@alexander-akait alexander-akait deleted the refactor-exports-presence-guard branch July 3, 2026 09:44
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment

Labels

None yet

Projects

None yet

Development

Successfully merging this pull request may close these issues.

2 participants