Upgrade to swc 56 #89111

mischnic · 2026-01-27T14:15:16Z

The only breaking change: swc-project/swc#11457

mischnic · 2026-01-27T14:15:37Z

Upgrade to swc 56 #89111 👈 (View in Graphite)
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nextjs-bot · 2026-01-27T14:24:36Z

Failing test suites

Commit: 743249c | About building and testing Next.js

pnpm test packages/next/src/server/app-render/action-handler.test.ts (job)

Expand output

● Test suite failed to run

Jest encountered an unexpected token

Jest failed to parse a file. This happens e.g. when your code or its dependencies use non-standard JavaScript syntax, or when Jest is not configured to support such syntax.

Out of the box Jest supports Babel, which will be used to transform your files into valid JS based on your Babel configuration.

By default "node_modules" folder is ignored by transformers.

Here's what you can do:
 • If you are trying to use ECMAScript Modules, see https://jestjs.io/docs/ecmascript-modules for how to enable it.
 • If you are trying to use TypeScript, see https://jestjs.io/docs/getting-started#using-typescript
 • To have some of your "node_modules" files transformed, you can specify a custom "transformIgnorePatterns" in your config.
 • If you need a custom transformation specify a "transform" option in your config.
 • If you simply want to mock your non-JS modules (e.g. binary assets) you can stub them out with the "moduleNameMapper" config option.

You'll find more details and examples of these config options in the docs:
https://jestjs.io/docs/configuration
For information about custom transformations, see:
https://jestjs.io/docs/code-transformation

Details:

C:\actions-runner\_work\next.js\next.js\packages\next\src\server\app-render\action-handler.ts:1
({"Object.<anonymous>":function(module,exports,require,__dirname,__filename,jest){import { RSC_HEADER, RSC_CONTENT_TYPE_HEADER, NEXT_ROUTER_STATE_TREE_HEADER, ACTION_HEADER, NEXT_ACTION_NOT_FOUND_HEADER, NEXT_ROUTER_PREFETCH_HEADER, NEXT_ROUTER_SEGMENT_PREFETCH_HEADER, NEXT_URL, NEXT_ACTION_REVALIDATED_HEADER } from '../../client/components/app-router-headers';
                                                                                  ^^^^^^

SyntaxError: Cannot use import statement outside a module

  3 | describe('parseHostHeader', () => {
  4 |   it('should return correct host', () => {
> 5 |     expect(parseHostHeader({})).toBe(undefined)
    |                        ^
  6 |
  7 |     expect(
  8 |       parseHostHeader({

  at Runtime.createScriptFromCode (../node_modules/.pnpm/jest-runtime@29.7.0/node_modules/jest-runtime/build/index.js:1505:14)
  at Object.<anonymous> (../packages/next/src/server/app-render/action-handler.test.ts:5:24)

nextjs-bot · 2026-01-27T14:39:41Z

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)	456ms	455ms	✓	▁█▁▁▁
Cold (Ready in log)	454ms	451ms	✓	▂█▁▂▂
Cold (First Request)	917ms	911ms	✓	▂█▁▅▄
Warm (Listen)	456ms	455ms	✓	▁█▁▁▁
Warm (Ready in log)	454ms	454ms	✓	▁█▁▁▁
Warm (First Request)	366ms	366ms	✓	▂█▁▂▁

📦 Dev Server (Webpack) (Legacy)

📦 Dev Server (Webpack)

Metric	Canary	PR	Change	Trend
Cold (Listen)	456ms	455ms	✓	█▁█▁█
Cold (Ready in log)	439ms	438ms	✓	▆▆▇▅▆
Cold (First Request)	1.833s	1.821s	✓	▄▃▅▃▃
Warm (Listen)	455ms	456ms	✓	▁▅▅█▅
Warm (Ready in log)	438ms	437ms	✓	▅▄▅▄▄
Warm (First Request)	1.855s	1.838s	✓	▄▃▅▃▃

⚡ Production Builds

Metric	Canary	PR	Change	Trend
Fresh Build	4.433s	4.465s	✓	▃█▂▁▁
Cached Build	4.434s	4.439s	✓	▃█▂▁▁

📦 Production Builds (Webpack) (Legacy)

📦 Production Builds (Webpack)

Metric	Canary	PR	Change	Trend
Fresh Build	13.791s	13.802s	✓	▂▁▄▁▁
Cached Build	13.839s	13.839s	✓	▂▁▄▁▁
node_modules Size	464 MB	464 MB	✓	▁▁▁▁▁

📦 Bundle Sizes

Bundle Sizes

⚡ Turbopack

Client

Main Bundles: **434 kB** → **434 kB** ✅ -11 B

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

Server

Middleware

	Canary	PR	Change
middleware-b..fest.js gzip	763 B	770 B	✓
Total	763 B	770 B	⚠️ +7 B

Build Details

Build Manifests

	Canary	PR	Change
_buildManifest.js gzip	451 B	450 B	✓
Total	451 B	450 B	✅ -1 B

📦 Webpack

Client

Main Bundles

	Canary	PR	Change
5528-HASH.js gzip	5.47 kB	N/A	-
6280-HASH.js gzip	54.5 kB	N/A	-
6335.HASH.js gzip	169 B	N/A	-
912-HASH.js gzip	4.53 kB	N/A	-
e8aec2e4-HASH.js gzip	62.5 kB	N/A	-
framework-HASH.js gzip	59.7 kB	59.7 kB	✓
main-app-HASH.js gzip	256 B	256 B	✓
main-HASH.js gzip	39 kB	39 kB	✓
webpack-HASH.js gzip	1.68 kB	1.68 kB	✓
262-HASH.js gzip	N/A	4.52 kB	-
2889.HASH.js gzip	N/A	169 B	-
5602-HASH.js gzip	N/A	5.48 kB	-
6948ada0-HASH.js gzip	N/A	62.5 kB	-
9544-HASH.js gzip	N/A	55.2 kB	-
Total	228 kB	228 kB	⚠️ +673 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	2.49 kB	2.49 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	7.97 kB	7.97 kB	✅ -1 B

Server

Edge SSR

	Canary	PR	Change
edge-ssr.js gzip	126 kB	126 kB	✓
page.js gzip	248 kB	249 kB	✓
Total	375 kB	375 kB	⚠️ +132 B

Middleware

	Canary	PR	Change
middleware-b..fest.js gzip	616 B	614 B	✓
middleware-r..fest.js gzip	156 B	155 B	✓
middleware.js gzip	33 kB	33 kB	✓
edge-runtime..pack.js gzip	842 B	842 B	✓
Total	34.6 kB	34.6 kB	⚠️ +55 B

Build Details

Build Manifests

	Canary	PR	Change
_buildManifest.js gzip	732 B	736 B	✓
Total	732 B	736 B	⚠️ +4 B

Build Cache

	Canary	PR	Change
0.pack gzip	3.79 MB	3.8 MB	🔴 +10.8 kB (+0%)
index.pack gzip	103 kB	103 kB	✓
index.pack.old gzip	101 kB	102 kB	🔴 +1.09 kB (+1%)
Total	4 MB	4.01 MB	⚠️ +11.5 kB

🔄 Shared (bundler-independent)

Runtimes

	Canary	PR	Change
app-page-exp...dev.js gzip	311 kB	311 kB	✓
app-page-exp..prod.js gzip	166 kB	166 kB	✓
app-page-tur...dev.js gzip	311 kB	311 kB	✓
app-page-tur..prod.js gzip	166 kB	166 kB	✓
app-page-tur...dev.js gzip	308 kB	308 kB	✓
app-page-tur..prod.js gzip	164 kB	164 kB	✓
app-page.run...dev.js gzip	308 kB	308 kB	✓
app-page.run..prod.js gzip	164 kB	164 kB	✓
app-route-ex...dev.js gzip	70.4 kB	70.4 kB	✓
app-route-ex..prod.js gzip	48.9 kB	48.9 kB	✓
app-route-tu...dev.js gzip	70.4 kB	70.4 kB	✓
app-route-tu..prod.js gzip	49 kB	49 kB	✓
app-route-tu...dev.js gzip	70 kB	70 kB	✓
app-route-tu..prod.js gzip	48.7 kB	48.7 kB	✓
app-route.ru...dev.js gzip	70 kB	70 kB	✓
app-route.ru..prod.js gzip	48.7 kB	48.7 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	43.1 kB	43.1 kB	✓
pages-api-tu..prod.js gzip	32.9 kB	32.9 kB	✓
pages-api.ru...dev.js gzip	43.1 kB	43.1 kB	✓
pages-api.ru..prod.js gzip	32.8 kB	32.8 kB	✓
pages-turbo....dev.js gzip	52.4 kB	52.4 kB	✓
pages-turbo...prod.js gzip	39.4 kB	39.4 kB	✓
pages.runtim...dev.js gzip	52.4 kB	52.4 kB	✓
pages.runtim..prod.js gzip	39.3 kB	39.3 kB	✓
server.runti..prod.js gzip	62.5 kB	62.5 kB	✓
Total	2.77 MB	2.77 MB	⚠️ +1 B

📝 Changed Files (4 files)

Files with changes:

pages-api-tu..ntime.dev.js
pages-api-tu..time.prod.js
pages-turbo...ntime.dev.js
pages-turbo...time.prod.js

View diffs

pages-api-tu..ntime.dev.js

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pages-api-tu..time.prod.js

Diff too large to display

pages-turbo...ntime.dev.js

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pages-turbo...time.prod.js

Diff too large to display

codspeed-hq · 2026-01-27T14:40:02Z

Merging this PR will not alter performance

✅ 17 untouched benchmarks
⏩ 3 skipped benchmarks¹

_{Comparing mischnic/swc-56 (743249c) with canary (9d2d242)}

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. ↩

graphite-app · 2026-01-31T02:17:23Z

Merge activity

Jan 31, 2:17 AM UTC: Graphite rebased this pull request, because this pull request is set to merge when ready.

nextjs-bot added created-by: Turbopack team PRs by the Turbopack team. Turbopack Related to Turbopack with Next.js. labels Jan 27, 2026

mischnic changed the title ~~Upgrade to swc 55~~ Jan 27, 2026

mischnic requested a review from a team January 27, 2026 14:15

mischnic marked this pull request as ready for review January 27, 2026 14:15

bgw approved these changes Jan 27, 2026

View reviewed changes

lukesandberg approved these changes Jan 28, 2026

View reviewed changes

mischnic force-pushed the mischnic/swc-56 branch 3 times, most recently from c0ef559 to 1f372e5 Compare January 29, 2026 09:04

mischnic added 6 commits January 31, 2026 02:16

Upgrade to swc 55

8a7a9c1

fix

bc44d1c

Upgrade to swc 56

6a0ffb2

cleanup unused crate

0504b50

fix breaking change

a552df8

modules transform is needed by next/jest

743249c

mischnic force-pushed the mischnic/swc-56 branch from 1f372e5 to 743249c Compare January 31, 2026 02:16

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Upgrade to swc 56 #89111

Upgrade to swc 56 #89111

mischnic commented Jan 27, 2026 •

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Upgrade to swc 56 #89111

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Stats from current PR

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⚡ Dev Server

📦 Dev Server (Webpack)

⚡ Production Builds

📦 Production Builds (Webpack)

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⚡ Turbopack

📦 Webpack

🔄 Shared (bundler-independent)

codspeed-hq bot commented Jan 27, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

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Merging this PR will not alter performance

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