Fix syntax contexts in server action transform by mischnic · Pull Request #91210 · vercel/next.js

mischnic · 2026-03-11T17:10:50Z

let x: Ident = IdentName::new(name, span).into();

should never be done. It uses SyntaxContext::default() for the Ident. So from swc's perspective, you are referring to a different variable than you think. When constructing an Ident, you should usually always provide a SyntaxContext.

I think this would pose a problem in Webpack because it serializes it into a code string again, but for Turbopack these SyntaxContext are important.

mischnic · 2026-03-11T17:11:04Z

Turbopack: reimplement server actions using emit/collect #91212
Turbopack: emit/collect #91100
Fix syntax contexts in server action transform #91210 👈 (View in Graphite)
canary

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nextjs-bot · 2026-03-11T17:31:38Z

Failing test suites

Commit: 8f9f1a8 | About building and testing Next.js

pnpm test-start test/e2e/app-dir/next-after-app-static/build-time/build-time.test.ts (job)

after() in static pages > runs after during build (DD)

Expand output

● after() in static pages › runs after during build

can not run export while server is running, use next.stop() first

  251 |   ) {
  252 |     if (this.childProcess) {
> 253 |       throw new Error(
      |             ^
  254 |         `can not run export while server is running, use next.stop() first`
  255 |       )
  256 |     }

  at NextStartInstance.build (lib/next-modes/next-start.ts:253:13)
  at Object.build (e2e/app-dir/next-after-app-static/build-time/build-time.test.ts:36:36)

codspeed-hq · 2026-03-11T17:35:47Z

Merging this PR will improve performance by 3.02%

⚡ 1 improved benchmark
✅ 16 untouched benchmarks
⏩ 3 skipped benchmarks¹

Performance Changes

	Mode	Benchmark	`BASE`	`HEAD`	Efficiency
⚡	Simulation	`packages-bundle.js[full]`	1.2 s	1.2 s	+3.02%

_{Comparing mischnic/fix-server-action-syntax-context (8f9f1a8) with canary (29812f2)}

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. ↩

nextjs-bot · 2026-03-11T17:37:42Z

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)	914ms	915ms	✓	█▁▁▁█
Cold (Ready in log)	904ms	910ms	✓	▅▆██▃
Cold (First Request)	1.672s	1.638s	✓	▃███▁
Warm (Listen)	965ms	962ms	✓	█▁▁▁▁
Warm (Ready in log)	927ms	927ms	✓	▇▁▂▂▅
Warm (First Request)	707ms	705ms	✓	▆▄▂▇▅

📦 Dev Server (Webpack) (Legacy)

📦 Dev Server (Webpack)

Metric	Canary	PR	Change	Trend
Cold (Listen)	456ms	455ms	✓	▁▁▁▁▁
Cold (Ready in log)	434ms	435ms	✓	▃▃▁▃▁
Cold (First Request)	1.875s	1.844s	✓	▂▂▁▂▁
Warm (Listen)	456ms	456ms	✓	▁▁▁▁▁
Warm (Ready in log)	435ms	435ms	✓	▄▃▁▃▁
Warm (First Request)	1.844s	1.860s	✓	▂▂▁▂▁

⚡ Production Builds

Metric	Canary	PR	Change	Trend
Fresh Build	6.367s	6.516s	✓	▇▁▁▁▂
Cached Build	6.377s	6.433s	✓	▇▁▁▁▃

📦 Production Builds (Webpack) (Legacy)

📦 Production Builds (Webpack)

Metric	Canary	PR	Change	Trend
Fresh Build	13.981s	13.915s	✓	▁▁▁▁▁
Cached Build	14.192s	14.127s	✓	▁▁▁▁▁
node_modules Size	477 MB	477 MB	✓	▁▁▁▁▁

📦 Bundle Sizes

Bundle Sizes

⚡ Turbopack

Client

Main Bundles: **402 kB** → **402 kB** ✅ -25 B

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

Server

Middleware

	Canary	PR	Change
middleware-b..fest.js gzip	770 B	764 B	✓
Total	770 B	764 B	✅ -6 B

Build Details

Build Manifests

	Canary	PR	Change
_buildManifest.js gzip	450 B	451 B	✓
Total	450 B	451 B	⚠️ +1 B

📦 Webpack

Client

Main Bundles

	Canary	PR	Change
5528-HASH.js gzip	5.54 kB	N/A	-
6280-HASH.js gzip	59.6 kB	N/A	-
6335.HASH.js gzip	169 B	N/A	-
912-HASH.js gzip	4.59 kB	N/A	-
e8aec2e4-HASH.js gzip	62.6 kB	N/A	-
framework-HASH.js gzip	59.7 kB	59.7 kB	✓
main-app-HASH.js gzip	255 B	252 B	🟢 3 B (-1%)
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	62.6 kB	-
9544-HASH.js gzip	N/A	60.3 kB	-
Total	233 kB	234 kB	⚠️ +731 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	257 kB	257 kB	✓
Total	382 kB	382 kB	⚠️ +403 B

Middleware

	Canary	PR	Change
middleware-b..fest.js gzip	618 B	616 B	✓
middleware-r..fest.js gzip	156 B	155 B	✓
middleware.js gzip	43.8 kB	43.9 kB	✓
edge-runtime..pack.js gzip	842 B	842 B	✓
Total	45.4 kB	45.5 kB	⚠️ +91 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	4.07 MB	4.08 MB	✓
index.pack gzip	103 kB	102 kB	✓
index.pack.old gzip	104 kB	104 kB	✓
Total	4.28 MB	4.28 MB	⚠️ +2.29 kB

🔄 Shared (bundler-independent)

Runtimes

	Canary	PR	Change
app-page-exp...dev.js gzip	323 kB	323 kB	✓
app-page-exp..prod.js gzip	171 kB	171 kB	✓
app-page-tur...dev.js gzip	322 kB	322 kB	✓
app-page-tur..prod.js gzip	171 kB	171 kB	✓
app-page-tur...dev.js gzip	319 kB	319 kB	✓
app-page-tur..prod.js gzip	169 kB	169 kB	✓
app-page.run...dev.js gzip	319 kB	319 kB	✓
app-page.run..prod.js gzip	170 kB	170 kB	✓
app-route-ex...dev.js gzip	70.9 kB	70.9 kB	✓
app-route-ex..prod.js gzip	49.3 kB	49.3 kB	✓
app-route-tu...dev.js gzip	70.9 kB	70.9 kB	✓
app-route-tu..prod.js gzip	49.3 kB	49.3 kB	✓
app-route-tu...dev.js gzip	70.5 kB	70.5 kB	✓
app-route-tu..prod.js gzip	49.1 kB	49.1 kB	✓
app-route.ru...dev.js gzip	70.5 kB	70.5 kB	✓
app-route.ru..prod.js gzip	49 kB	49 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	32.9 kB	32.9 kB	✓
pages-api.ru...dev.js gzip	43.2 kB	43.2 kB	✓
pages-api.ru..prod.js gzip	32.9 kB	32.9 kB	✓
pages-turbo....dev.js gzip	52.6 kB	52.6 kB	✓
pages-turbo...prod.js gzip	38.5 kB	38.5 kB	✓
pages.runtim...dev.js gzip	52.6 kB	52.6 kB	✓
pages.runtim..prod.js gzip	38.5 kB	38.5 kB	✓
server.runti..prod.js gzip	62 kB	62 kB	✓
Total	2.84 MB	2.84 MB	⚠️ +1 B

📎 Tarball URL

https://vercel-packages.vercel.app/next/commits/8f9f1a8dc0abecf0f0f77a7375162c3b539cbdbf/next

unstubbable

ACK

nextjs-bot added created-by: Turbopack team PRs by the Turbopack team. Turbopack Related to Turbopack with Next.js. labels Mar 11, 2026

mischnic marked this pull request as ready for review March 11, 2026 17:13

mischnic changed the title ~~server actions: fix syntax contexts~~ Fix syntax contexts in server action transform. Mar 11, 2026

mischnic changed the title ~~Fix syntax contexts in server action transform.~~ Fix syntax contexts in server action transform Mar 11, 2026

mischnic requested review from a team and unstubbable March 11, 2026 17:14

This was referenced Mar 11, 2026

Turbopack: emit/collect #91100

Draft

Turbopack: reimplement server actions using emit/collect #91212

Draft

server actions: fix syntax contexts

8f9f1a8

mischnic force-pushed the mischnic/fix-server-action-syntax-context branch from d12749b to 8f9f1a8 Compare March 11, 2026 18:32

unstubbable approved these changes Mar 11, 2026

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mischnic merged commit 196ed2b into canary Mar 11, 2026
286 of 288 checks passed

mischnic deleted the mischnic/fix-server-action-syntax-context branch March 11, 2026 21:16

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Fix syntax contexts in server action transform#91210

Fix syntax contexts in server action transform#91210
mischnic merged 1 commit intocanaryfrom
mischnic/fix-server-action-syntax-context

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