fix parallel route top-level catch-all normalization logic to support nested explicit (non-catchall) slot routes

[williamli]

Fix NEXT-2165

What?

Addresses the limitation of #60240, where a dummy default file is required in parallel route child slot to prevent errors in dev server rendering (TypeError: Cannot read properties of undefined (reading 'clientModules')) as well as errors in build and deploy (Error: ENOENT: no such file or directory, lstat ‘/vercel/path0/.next/server/app/parallel-route/[section]/@part/[partSlug]/page_client-reference-manifest.js’)

Without the default.tsx, builds and deployments will fail with:

local dev server will also crash with:

TypeError: Cannot read properties of undefined (reading 'clientModules')

Why?

Since default.tsx is not a compulsory when you have slot that are specific and ends with a dynamic route segment, this PR extends support so that it is possible mixing catch-all routes with specific non-catchall routes without requiring an additional default.tsx .

This PR will allow the following test cases to pass:

it('should not add the catch-all route to segments that have a more specific [dynamicRoute]', () => {
    const appPaths = {
      '/': ['/page'],
      '/[[...catchAll]]': ['/[[...catchAll]]/page'],
      '/nested/[foo]/[bar]/default': [
        '/nested/[foo]/[bar]/default',
        '/nested/[foo]/[bar]/@slot0/default',
        '/nested/[foo]/[bar]/@slot2/default',
      ],
      '/nested/[foo]/[bar]': [
        '/nested/[foo]/[bar]/@slot0/page',
        '/nested/[foo]/[bar]/@slot1/page',
      ],
      '/nested/[foo]/[bar]/[baz]': [
        '/nested/[foo]/[bar]/@slot0/[baz]/page',
        '/nested/[foo]/[bar]/@slot1/[baz]/page',
      ],
      '/[locale]/nested/[foo]/[bar]/[baz]/[qux]': [
        '/[locale]/nested/[foo]/[bar]/@slot1/[baz]/[qux]/page',
      ],
    }

    const initialAppPaths = JSON.parse(JSON.stringify(appPaths))
    normalizeCatchAllRoutes(appPaths)
    expect(appPaths).toMatchObject(initialAppPaths)
  })
...

    const appPaths = {
      '/': ['/page'],
      '/[[...catchAll]]': ['/[[...catchAll]]/page'],
      '/nested/[foo]/[bar]/default': [
        '/nested/[foo]/[bar]/default',
        '/nested/[foo]/[bar]/@slot0/default',
        '/nested/[foo]/[bar]/@slot2/default',
      ],
      '/nested/[foo]/[bar]': [
        '/nested/[foo]/[bar]/@slot0/page',
        '/nested/[foo]/[bar]/@slot1/page',
      ],
      '/nested/[foo]/[bar]/[baz]': [
        '/nested/[foo]/[bar]/@slot0/[baz]/page',
        '/nested/[foo]/[bar]/@slot1/[baz]/page',
      ],
      '/[locale]/nested/[foo]/[bar]/[baz]/[qux]': [
        '/[locale]/nested/[foo]/[bar]/@slot1/[baz]/[qux]/page',
      ],
    }
...

and allow parallel routes defined in this code repro to build.

How?

packages/next/src/build/normalize-catchall-routes.ts is extended to check appPath to see if it is:

1. the route is not a catchall
2. isMoreSpecific than the closest catchAllRoute.

where isMoreSpecific is defined as:

function isMoreSpecific(pathname: string, catchAllRoute: string): boolean {
  const pathnameDepth = pathname.split('/').length
  const catchAllRouteDepth = catchAllRoute.split('/').length - 1
  return pathnameDepth > catchAllRouteDepth
}

[ijjk]

Failing test suites

Commit: 27d096d

pnpm test-dev test/e2e/app-dir/not-found/basic/index.test.ts (PPR)

• app dir - not-found - basic > with runtime = edge > should render the 404 page when the file is removed, and restore the page when re-added

Expand output

● app dir - not-found - basic › with runtime = edge › should render the 404 page when the file is removed, and restore the page when re-added

TIMED OUT: Root Not Found

My page

TimeoutError: page.waitForSelector: Timeout 60000ms exceeded.
=========================== logs ===========================
waiting for locator('h1')
============================================================

  636 |
  637 |   if (hardError) {
> 638 |     throw new Error('TIMED OUT: ' + regex + '\n\n' + content + '\n\n' + lastErr)
      |           ^
  639 |   }
  640 |   return false
  641 | }

  at check (lib/next-test-utils.ts:638:11)
  at Object.<anonymous> (e2e/app-dir/not-found/basic/index.test.ts:123:11)

Read more about building and testing Next.js in contributing.md.

[ijjk]

Stats from current PR

Default Build

General Overall increase ⚠️

	vercel/next.js canary	williamli/next.js fix-parallel-routes-top-level-catchall-but-no-default	Change
buildDuration	11.7s	11.8s	N/A
buildDurationCached	6s	5s	N/A
nodeModulesSize	200 MB	200 MB	⚠️ +3.04 kB
nextStartRea..uration (ms)	424ms	433ms	N/A

Client Bundles (main, webpack)

	vercel/next.js canary	williamli/next.js fix-parallel-routes-top-level-catchall-but-no-default	Change
193.HASH.js gzip	181 B	182 B	N/A
3f784ff6-HASH.js gzip	53.4 kB	53.4 kB	✓
433-HASH.js gzip	29 kB	29 kB	N/A
framework-HASH.js gzip	45.2 kB	45.2 kB	✓
main-app-HASH.js gzip	239 B	242 B	N/A
main-HASH.js gzip	31.8 kB	31.8 kB	N/A
webpack-HASH.js gzip	1.7 kB	1.7 kB	N/A
Overall change	98.6 kB	98.6 kB	✓

Legacy Client Bundles (polyfills)

	vercel/next.js canary	williamli/next.js fix-parallel-routes-top-level-catchall-but-no-default	Change
polyfills-HASH.js gzip	31 kB	31 kB	✓
Overall change	31 kB	31 kB	✓

Client Pages

	vercel/next.js canary	williamli/next.js fix-parallel-routes-top-level-catchall-but-no-default	Change
_app-HASH.js gzip	194 B	195 B	N/A
_error-HASH.js gzip	183 B	181 B	N/A
amp-HASH.js gzip	504 B	502 B	N/A
css-HASH.js gzip	321 B	321 B	✓
dynamic-HASH.js gzip	2.5 kB	2.5 kB	N/A
edge-ssr-HASH.js gzip	255 B	253 B	N/A
head-HASH.js gzip	350 B	349 B	N/A
hooks-HASH.js gzip	369 B	369 B	✓
image-HASH.js gzip	4.18 kB	4.18 kB	N/A
index-HASH.js gzip	255 B	256 B	N/A
link-HASH.js gzip	2.61 kB	2.61 kB	✓
routerDirect..HASH.js gzip	312 B	311 B	N/A
script-HASH.js gzip	385 B	383 B	N/A
withRouter-HASH.js gzip	307 B	308 B	N/A
1afbb74e6ecf..834.css gzip	106 B	106 B	✓
Overall change	3.4 kB	3.4 kB	✓

Client Build Manifests

	vercel/next.js canary	williamli/next.js fix-parallel-routes-top-level-catchall-but-no-default	Change
_buildManifest.js gzip	484 B	485 B	N/A
Overall change	0 B	0 B	✓

Rendered Page Sizes

	vercel/next.js canary	williamli/next.js fix-parallel-routes-top-level-catchall-but-no-default	Change
index.html gzip	528 B	525 B	N/A
link.html gzip	540 B	538 B	N/A
withRouter.html gzip	524 B	522 B	N/A
Overall change	0 B	0 B	✓

Edge SSR bundle Size

	vercel/next.js canary	williamli/next.js fix-parallel-routes-top-level-catchall-but-no-default	Change
edge-ssr.js gzip	94 kB	94 kB	N/A
page.js gzip	149 kB	149 kB	N/A
Overall change	0 B	0 B	✓

Middleware size

	vercel/next.js canary	williamli/next.js fix-parallel-routes-top-level-catchall-but-no-default	Change
middleware-b..fest.js gzip	626 B	627 B	N/A
middleware-r..fest.js gzip	151 B	151 B	✓
middleware.js gzip	37.5 kB	37.5 kB	N/A
edge-runtime..pack.js gzip	1.92 kB	1.92 kB	✓
Overall change	2.07 kB	2.07 kB	✓

Next Runtimes

	vercel/next.js canary	williamli/next.js fix-parallel-routes-top-level-catchall-but-no-default	Change
app-page-exp...dev.js gzip	169 kB	169 kB	✓
app-page-exp..prod.js gzip	95.6 kB	95.6 kB	✓
app-page-tur..prod.js gzip	96.3 kB	96.3 kB	✓
app-page-tur..prod.js gzip	90.9 kB	90.9 kB	✓
app-page.run...dev.js gzip	142 kB	142 kB	✓
app-page.run..prod.js gzip	90.2 kB	90.2 kB	✓
app-route-ex...dev.js gzip	24.2 kB	24.2 kB	✓
app-route-ex..prod.js gzip	16.9 kB	16.9 kB	✓
app-route-tu..prod.js gzip	16.9 kB	16.9 kB	✓
app-route-tu..prod.js gzip	16.4 kB	16.4 kB	✓
app-route.ru...dev.js gzip	23.6 kB	23.6 kB	✓
app-route.ru..prod.js gzip	16.4 kB	16.4 kB	✓
pages-api-tu..prod.js gzip	9.41 kB	9.41 kB	✓
pages-api.ru...dev.js gzip	9.68 kB	9.68 kB	✓
pages-api.ru..prod.js gzip	9.4 kB	9.4 kB	✓
pages-turbo...prod.js gzip	22 kB	22 kB	✓
pages.runtim...dev.js gzip	22.6 kB	22.6 kB	✓
pages.runtim..prod.js gzip	22 kB	22 kB	✓
server.runti..prod.js gzip	49.7 kB	49.7 kB	✓
Overall change	944 kB	944 kB	✓

Commit: 21ffa68

[ztanner]

Thanks!