Fix Router Error Events in Shallow Routing by Skipping cancelHandler Creation

[rvetere]

Problem

We've identified a bug within Next.js's pages router when utilizing the shallow routing API, specifically when invoking router.push with the { shallow: true } option, like so:

router.push('/?counter=10', undefined, { shallow: true });

Shallow routing is designed to update the URL without running data fetching methods such as getServerSideProps, getStaticProps, or getInitialProps. However, a side effect of this process is that it skips the clean-up of the cancelHandler. This leads to router error events being fired erroneously, causing confusion and potential stability issues, as the system behaves as if an error occurred when, in fact, none did.

Solution

This PR addresses the issue by modifying the shallow routing logic to also skip the creation of the cancelHandler. Given that shallow routing operations are synchronous and do not involve data fetching or other asynchronous tasks that might need to be canceled, the cancelHandler is unnecessary in this context.

fixes #61772

[shuding]

Thanks a lot!

[shuding]

There’s a lint error in the test. Could you please update that? Thanks!

[rvetere]

All checks are green now, thanks for the approval! <3

[rvetere]

Hey @shuding, will this PR be merged/integrated into the next release? I would like to know to plan our stories accordingly, because if not, i should start to implement a huge workaround in our project as this bug is becoming more and more critical for our business

[ijjk]

Stats from current PR

Default Build

General

	vercel/next.js canary	rvetere/next.js canary	Change
buildDuration	13.9s	13.9s	N/A
buildDurationCached	8.6s	6.2s	N/A
nodeModulesSize	197 MB	197 MB	✓
nextStartRea..uration (ms)	407ms	407ms	✓

Client Bundles (main, webpack)

	vercel/next.js canary	rvetere/next.js canary	Change
2453-HASH.js gzip	30.5 kB	30.5 kB	N/A
3304.HASH.js gzip	181 B	181 B	✓
3f784ff6-HASH.js gzip	53.7 kB	53.7 kB	N/A
8299-HASH.js gzip	5.04 kB	5.04 kB	N/A
framework-HASH.js gzip	45.2 kB	45.2 kB	✓
main-app-HASH.js gzip	242 B	242 B	✓
main-HASH.js gzip	32.1 kB	32.2 kB	N/A
webpack-HASH.js gzip	1.7 kB	1.7 kB	N/A
Overall change	45.6 kB	45.6 kB	✓

Legacy Client Bundles (polyfills)

	vercel/next.js canary	rvetere/next.js canary	Change
polyfills-HASH.js gzip	31 kB	31 kB	✓
Overall change	31 kB	31 kB	✓

Client Pages

	vercel/next.js canary	rvetere/next.js canary	Change
_app-HASH.js gzip	196 B	197 B	N/A
_error-HASH.js gzip	184 B	184 B	✓
amp-HASH.js gzip	505 B	505 B	✓
css-HASH.js gzip	324 B	325 B	N/A
dynamic-HASH.js gzip	2.5 kB	2.5 kB	N/A
edge-ssr-HASH.js gzip	258 B	258 B	✓
head-HASH.js gzip	352 B	352 B	✓
hooks-HASH.js gzip	370 B	371 B	N/A
image-HASH.js gzip	4.2 kB	4.2 kB	✓
index-HASH.js gzip	259 B	259 B	✓
link-HASH.js gzip	2.67 kB	2.67 kB	N/A
routerDirect..HASH.js gzip	314 B	312 B	N/A
script-HASH.js gzip	386 B	386 B	✓
withRouter-HASH.js gzip	309 B	309 B	✓
1afbb74e6ecf..834.css gzip	106 B	106 B	✓
Overall change	6.56 kB	6.56 kB	✓

Client Build Manifests

	vercel/next.js canary	rvetere/next.js canary	Change
_buildManifest.js gzip	483 B	485 B	N/A
Overall change	0 B	0 B	✓

Rendered Page Sizes

	vercel/next.js canary	rvetere/next.js canary	Change
index.html gzip	528 B	527 B	N/A
link.html gzip	541 B	540 B	N/A
withRouter.html gzip	525 B	521 B	N/A
Overall change	0 B	0 B	✓

Edge SSR bundle Size

	vercel/next.js canary	rvetere/next.js canary	Change
edge-ssr.js gzip	95.1 kB	95.1 kB	N/A
page.js gzip	3.05 kB	3.06 kB	N/A
Overall change	0 B	0 B	✓

Middleware size

	vercel/next.js canary	rvetere/next.js canary	Change
middleware-b..fest.js gzip	624 B	624 B	✓
middleware-r..fest.js gzip	151 B	151 B	✓
middleware.js gzip	25.5 kB	25.5 kB	N/A
edge-runtime..pack.js gzip	839 B	839 B	✓
Overall change	1.61 kB	1.61 kB	✓

Next Runtimes

	vercel/next.js canary	rvetere/next.js canary	Change
app-page-exp...dev.js gzip	171 kB	171 kB	✓
app-page-exp..prod.js gzip	96.7 kB	96.7 kB	✓
app-page-tur..prod.js gzip	98.5 kB	98.5 kB	✓
app-page-tur..prod.js gzip	92.9 kB	92.9 kB	✓
app-page.run...dev.js gzip	150 kB	150 kB	✓
app-page.run..prod.js gzip	91.4 kB	91.4 kB	✓
app-route-ex...dev.js gzip	21.3 kB	21.3 kB	✓
app-route-ex..prod.js gzip	15 kB	15 kB	✓
app-route-tu..prod.js gzip	15 kB	15 kB	✓
app-route-tu..prod.js gzip	14.8 kB	14.8 kB	✓
app-route.ru...dev.js gzip	20.9 kB	20.9 kB	✓
app-route.ru..prod.js gzip	14.8 kB	14.8 kB	✓
pages-api-tu..prod.js gzip	9.51 kB	9.51 kB	✓
pages-api.ru...dev.js gzip	9.79 kB	9.79 kB	✓
pages-api.ru..prod.js gzip	9.51 kB	9.51 kB	✓
pages-turbo...prod.js gzip	22.3 kB	22.3 kB	✓
pages.runtim...dev.js gzip	23 kB	23 kB	✓
pages.runtim..prod.js gzip	22.3 kB	22.3 kB	✓
server.runti..prod.js gzip	50.6 kB	50.6 kB	✓
Overall change	950 kB	950 kB	✓

build cache

	vercel/next.js canary	rvetere/next.js canary	Change
0.pack gzip	1.56 MB	1.56 MB	N/A
index.pack gzip	105 kB	105 kB	N/A
Overall change	0 B	0 B	✓

Diff details

Diff for middleware.js

Diff too large to display

Commit: e54c052