[turbopack] Remove turbo_tasks::function from ModuleReference getters

[lukesandberg]

What?

Refactors the ModuleReference trait to make chunking_type() and binding_usage() methods return direct values instead of Vc<T> wrapped values, removing the need for async task functions.

Also removes the get_referenced_asset task from EsmAssetReference, inlining its logic into the callers.

Why?

This change simplifies the API by eliminating unnecessary async overhead for methods that typically return simple, computed values. The previous implementation required #[turbo_tasks::function] annotations and Vc<T> wrappers even when the methods didn't need to perform async operations or benefit from caching.

Impact

Metric	Base	Change	Delta
Hits	35,678,143	35,845,124	+166,981
Misses	9,418,378	7,910,986	-1,507,392
Total	45,096,521	43,756,110	-1,340,411
Task types	1,306	1,277	-29

29 task types were removed, eliminating 2.6M total task invocations (1.1M hits + 1.5M misses):

• chunking_type — 21 task types removed across all ModuleReference implementors (~952k invocations)
• binding_usage — 6 task types removed (~527k invocations)
• BindingUsage::all — helper task removed (~36k invocations)
• EsmAssetReference::get_referenced_asset — removed and inlined (~1.08M invocations: 628k hits + 451k misses)

The removed get_referenced_asset hits reappear as +628k hits on EsmAssetReference::resolve_reference and ReferencedAsset::from_resolve_result (with zero increase in misses), confirming the work is now served from cache through the existing callers.

No tasks had increased misses — the removal is clean with no cache invalidation spillover.

I also ran some builds to measure latency

# This branch
$ hyperfine -p 'rm -rf .next' -w 2 -r 10  'pnpm next build --turbopack --experimental-build-mode=compile'
Benchmark 1: pnpm next build --turbopack --experimental-build-mode=compile
  Time (mean ± σ):     52.752 s ±  0.658 s    [User: 376.575 s, System: 106.375 s]
  Range (min … max):   51.913 s … 54.161 s    10 runs

# on canary
$ hyperfine -p 'rm -rf .next' -w 2 -r 10  'pnpm next build --turbopack --experimental-build-mode=compile'
Benchmark 1: pnpm next build --turbopack --experimental-build-mode=compile
  Time (mean ± σ):     54.675 s ±  1.394 s    [User: 389.273 s, System: 114.642 s]
  Range (min … max):   53.434 s … 58.189 s    10 runs

so a solid win of almost 2 seconds

MaxRSS also went from 16,474,324,992 bytes to 16,359,309,312 bytes (from one measurement) so a savings of ~100M of max heap size.

How?

• Changed chunking_type() method signature from Vc<ChunkingTypeOption> to Option<ChunkingType>
• Changed binding_usage() method signature from Vc<BindingUsage> to BindingUsage
• Removed ChunkingTypeOption type alias as it's no longer needed
• Updated all implementations across the codebase to return direct values instead of wrapped ones
• Removed #[turbo_tasks::function] annotations from these methods
• Updated call sites to use into_trait_ref().await? pattern when accessing these methods from Vc<dyn ModuleReference>
• Removed EsmAssetReference::get_referenced_asset, inlining its logic into callers
• Added validation for turbopack-chunking-type annotation values in import analysis
• Fixed cache effectiveness analysis script

[lukesandberg]

• Turbopack: require(/* turbopackChunkingType: parallel */ #91278 : 2 dependent PRs (#91279 , #91317 )
• [turbopack] Remove turbo_tasks::function from ModuleReference getters #91229 👈 (View in Graphite)
• canary

This stack of pull requests is managed by Graphite. Learn more about stacking.

[nextjs-bot]

Failing test suites

Commit: 69d6b96 | About building and testing Next.js

[nextjs-bot]

Stats from current PR

✅ No significant changes detected

📊 All Metrics

📖 Metrics Glossary

Dev Server Metrics:

• Listen = TCP port starts accepting connections
• First Request = HTTP server returns successful response
• Cold = Fresh build (no cache)
• Warm = With cached build artifacts

Build Metrics:

• Fresh = Clean build (no .next directory)
• Cached = With existing .next directory

Change Thresholds:

• Time: Changes < 50ms AND < 10%, OR < 2% are insignificant
• Size: Changes < 1KB AND < 1% are insignificant
• All other changes are flagged to catch regressions

⚡ Dev Server

Metric	Canary	PR	Change	Trend
Cold (Listen)	455ms	455ms	✓	█▁▅▁▂
Cold (Ready in log)	437ms	438ms	✓	█▁▄▁▁
Cold (First Request)	1.275s	1.283s	✓	█▁▃▁▂
Warm (Listen)	456ms	456ms	✓	█▁▅▁▂
Warm (Ready in log)	442ms	443ms	✓	█▁▄▁▁
Warm (First Request)	352ms	349ms	✓	█▁▃▁▁

📦 Dev Server (Webpack) (Legacy)

📦 Dev Server (Webpack)

Metric	Canary	PR	Change	Trend
Cold (Listen)	455ms	456ms	✓	▁█▁▁▁
Cold (Ready in log)	439ms	437ms	✓	▃█▁▃▂
Cold (First Request)	1.954s	1.952s	✓	▂█▁▂▂
Warm (Listen)	455ms	456ms	✓	▁█▁▁▁
Warm (Ready in log)	439ms	438ms	✓	▂█▁▃▃
Warm (First Request)	1.960s	1.963s	✓	▁█▁▂▁

⚡ Production Builds

Metric	Canary	PR	Change	Trend
Fresh Build	3.933s	3.888s	✓	█▁▃▁▂
Cached Build	3.977s	3.980s	✓	█▁▃▁▂

📦 Production Builds (Webpack) (Legacy)

📦 Production Builds (Webpack)

Metric	Canary	PR	Change	Trend
Fresh Build	14.493s	14.333s	✓	▁█▁▁▁
Cached Build	14.395s	14.449s	✓	▁█▁▁▁
node_modules Size	482 MB	482 MB	✓	▁▁▁▁▁

📦 Bundle Sizes

Bundle Sizes

⚡ Turbopack

Client

Main Bundles: **408 kB** → **408 kB** ⚠️ +14 B

80 files with content-based hashes (individual files not comparable between builds)

Server

Middleware

	Canary	PR	Change
middleware-b..fest.js gzip	760 B	757 B	✓
Total	760 B	757 B	✅ -3 B

Build Details

Build Manifests

	Canary	PR	Change
_buildManifest.js gzip	450 B	449 B	✓
Total	450 B	449 B	✅ -1 B

📦 Webpack

Client

Main Bundles

	Canary	PR	Change
5528-HASH.js gzip	5.54 kB	N/A	-
6280-HASH.js gzip	59.9 kB	N/A	-
6335.HASH.js gzip	169 B	N/A	-
912-HASH.js gzip	4.59 kB	N/A	-
e8aec2e4-HASH.js gzip	62.7 kB	N/A	-
framework-HASH.js gzip	59.7 kB	59.7 kB	✓
main-app-HASH.js gzip	255 B	254 B	✓
main-HASH.js gzip	39.2 kB	39.2 kB	✓
webpack-HASH.js gzip	1.68 kB	1.68 kB	✓
262-HASH.js gzip	N/A	4.59 kB	-
2889.HASH.js gzip	N/A	169 B	-
5602-HASH.js gzip	N/A	5.55 kB	-
6948ada0-HASH.js gzip	N/A	62.7 kB	-
9544-HASH.js gzip	N/A	60.6 kB	-
Total	234 kB	235 kB	⚠️ +722 B

Polyfills

	Canary	PR	Change
polyfills-HASH.js gzip	39.4 kB	39.4 kB	✓
Total	39.4 kB	39.4 kB	✓

Pages

	Canary	PR	Change
_app-HASH.js gzip	194 B	194 B	✓
_error-HASH.js gzip	183 B	180 B	🟢 3 B (-2%)
css-HASH.js gzip	331 B	330 B	✓
dynamic-HASH.js gzip	1.81 kB	1.81 kB	✓
edge-ssr-HASH.js gzip	256 B	256 B	✓
head-HASH.js gzip	351 B	352 B	✓
hooks-HASH.js gzip	384 B	383 B	✓
image-HASH.js gzip	580 B	581 B	✓
index-HASH.js gzip	260 B	260 B	✓
link-HASH.js gzip	2.51 kB	2.51 kB	✓
routerDirect..HASH.js gzip	320 B	319 B	✓
script-HASH.js gzip	386 B	386 B	✓
withRouter-HASH.js gzip	315 B	315 B	✓
1afbb74e6ecf..834.css gzip	106 B	106 B	✓
Total	7.98 kB	7.98 kB	✅ -1 B

Server

Edge SSR

	Canary	PR	Change
edge-ssr.js gzip	125 kB	125 kB	✓
page.js gzip	267 kB	267 kB	✓
Total	392 kB	392 kB	✅ -264 B

Middleware

	Canary	PR	Change
middleware-b..fest.js gzip	616 B	613 B	✓
middleware-r..fest.js gzip	156 B	155 B	✓
middleware.js gzip	43.9 kB	44.1 kB	✓
edge-runtime..pack.js gzip	842 B	842 B	✓
Total	45.5 kB	45.7 kB	⚠️ +194 B

Build Details

Build Manifests

	Canary	PR	Change
_buildManifest.js gzip	715 B	718 B	✓
Total	715 B	718 B	⚠️ +3 B

Build Cache

	Canary	PR	Change
0.pack gzip	4.23 MB	4.23 MB	✓
index.pack gzip	107 kB	108 kB	✓
index.pack.old gzip	108 kB	109 kB	✓
Total	4.45 MB	4.45 MB	⚠️ +249 B

🔄 Shared (bundler-independent)

Runtimes

	Canary	PR	Change
app-page-exp...dev.js gzip	332 kB	332 kB	✓
app-page-exp..prod.js gzip	180 kB	180 kB	✓
app-page-tur...dev.js gzip	332 kB	332 kB	✓
app-page-tur..prod.js gzip	180 kB	180 kB	✓
app-page-tur...dev.js gzip	328 kB	328 kB	✓
app-page-tur..prod.js gzip	178 kB	178 kB	✓
app-page.run...dev.js gzip	329 kB	329 kB	✓
app-page.run..prod.js gzip	178 kB	178 kB	✓
app-route-ex...dev.js gzip	76 kB	76 kB	✓
app-route-ex..prod.js gzip	51.7 kB	51.7 kB	✓
app-route-tu...dev.js gzip	76 kB	76 kB	✓
app-route-tu..prod.js gzip	51.7 kB	51.7 kB	✓
app-route-tu...dev.js gzip	75.6 kB	75.6 kB	✓
app-route-tu..prod.js gzip	51.5 kB	51.5 kB	✓
app-route.ru...dev.js gzip	75.5 kB	75.5 kB	✓
app-route.ru..prod.js gzip	51.4 kB	51.4 kB	✓
dist_client_...dev.js gzip	324 B	324 B	✓
dist_client_...dev.js gzip	326 B	326 B	✓
dist_client_...dev.js gzip	318 B	318 B	✓
dist_client_...dev.js gzip	317 B	317 B	✓
pages-api-tu...dev.js gzip	43.3 kB	43.3 kB	✓
pages-api-tu..prod.js gzip	33 kB	33 kB	✓
pages-api.ru...dev.js gzip	43.3 kB	43.3 kB	✓
pages-api.ru..prod.js gzip	33 kB	33 kB	✓
pages-turbo....dev.js gzip	52.7 kB	52.7 kB	✓
pages-turbo...prod.js gzip	38.6 kB	38.6 kB	✓
pages.runtim...dev.js gzip	52.7 kB	52.7 kB	✓
pages.runtim..prod.js gzip	38.6 kB	38.6 kB	✓
server.runti..prod.js gzip	62.4 kB	62.4 kB	✓
Total	2.95 MB	2.95 MB	✅ -1 B

📎 Tarball URL

https://vercel-packages.vercel.app/next/commits/546b3223ab5c9ddb1054abb5a9d9f85dd06bda51/next

[codspeed-hq]

Merging this PR will improve performance by 6.66%

⚡ 3 improved benchmarks
✅ 14 untouched benchmarks
⏩ 3 skipped benchmarks¹

Performance Changes

	Mode	Benchmark	BASE	HEAD	Efficiency
⚡	Simulation	build[lucide-react-all]	7.3 s	6.8 s	+6.66%
⚡	Simulation	build[date-fns-all]	2.1 s	2 s	+3.63%
⚡	Simulation	build[framer-motion-all]	2.8 s	2.7 s	+3.39%

---

_{Comparing ineffective_tasks (69d6b96) with canary (80385f5)}

Footnotes

1. 3 benchmarks were skipped, so the baseline results were used instead. If they were deleted from the codebase, click here and archive them to remove them from the performance reports. ↩

[lukesandberg]

Merge activity

• Mar 13, 6:54 PM UTC: @lukesandberg merged this pull request with Graphite.