Fix external check for non-local next import

[ijjk]

This is a follow-up to #24603 ensuring we maintain the previous behavior to correctly externalize non-local next/dist/next-server imports, an added test case has been added to ensure we prevent regressing on this behavior.

Bug

• Related issues linked using fixes #number
• Integration tests added

Fixes: #25303

[ijjk]

Stats from current PR

Default Server Mode (Increase detected ⚠️)

General Overall increase ⚠️

	vercel/next.js canary	ijjk/next.js fix/next-external-check	Change
buildDuration	13s	12.2s	-878ms
buildDurationCached	3.4s	3.3s	-140ms
nodeModulesSize	46.7 MB	46.7 MB	⚠️ +422 B

Page Load Tests Overall increase ✓

	vercel/next.js canary	ijjk/next.js fix/next-external-check	Change
/ failed reqs	0	0	✓
/ total time (seconds)	2.481	2.25	-0.23
/ avg req/sec	1007.77	1111.11	+103.34
/error-in-render failed reqs	0	0	✓
/error-in-render total time (seconds)	1.332	1.294	-0.04
/error-in-render avg req/sec	1877.13	1931.9	+54.77

Client Bundles (main, webpack, commons)

	vercel/next.js canary	ijjk/next.js fix/next-external-check	Change
framework-HASH.js gzip	39.3 kB	39.3 kB	✓
main-HASH.js gzip	19.4 kB	19.4 kB	✓
webpack-HASH.js gzip	994 B	994 B	✓
Overall change	59.7 kB	59.7 kB	✓

Legacy Client Bundles (polyfills)

	vercel/next.js canary	ijjk/next.js fix/next-external-check	Change
polyfills-HASH.js gzip	31.1 kB	31.1 kB	✓
Overall change	31.1 kB	31.1 kB	✓

Client Pages

	vercel/next.js canary	ijjk/next.js fix/next-external-check	Change
_app-HASH.js gzip	1.02 kB	1.02 kB	✓
_error-HASH.js gzip	3.06 kB	3.06 kB	✓
amp-HASH.js gzip	526 B	526 B	✓
css-HASH.js gzip	334 B	334 B	✓
hooks-HASH.js gzip	890 B	890 B	✓
index-HASH.js gzip	262 B	262 B	✓
link-HASH.js gzip	1.65 kB	1.65 kB	✓
routerDirect..HASH.js gzip	331 B	331 B	✓
withRouter-HASH.js gzip	329 B	329 B	✓
bb14e60e810b..30f.css gzip	125 B	125 B	✓
Overall change	8.54 kB	8.54 kB	✓

Client Build Manifests

	vercel/next.js canary	ijjk/next.js fix/next-external-check	Change
_buildManifest.js gzip	390 B	390 B	✓
Overall change	390 B	390 B	✓

Rendered Page Sizes

	vercel/next.js canary	ijjk/next.js fix/next-external-check	Change
index.html gzip	560 B	560 B	✓
link.html gzip	568 B	568 B	✓
withRouter.html gzip	556 B	556 B	✓
Overall change	1.68 kB	1.68 kB	✓

---

Serverless Mode

General Overall increase ⚠️

	vercel/next.js canary	ijjk/next.js fix/next-external-check	Change
buildDuration	13.9s	13.8s	-132ms
buildDurationCached	4s	4.1s	⚠️ +41ms
nodeModulesSize	46.7 MB	46.7 MB	⚠️ +422 B

Client Bundles (main, webpack, commons)

	vercel/next.js canary	ijjk/next.js fix/next-external-check	Change
framework-HASH.js gzip	39.3 kB	39.3 kB	✓
main-HASH.js gzip	19.4 kB	19.4 kB	✓
webpack-HASH.js gzip	994 B	994 B	✓
Overall change	59.7 kB	59.7 kB	✓

Legacy Client Bundles (polyfills)

	vercel/next.js canary	ijjk/next.js fix/next-external-check	Change
polyfills-HASH.js gzip	31.1 kB	31.1 kB	✓
Overall change	31.1 kB	31.1 kB	✓

Client Pages

	vercel/next.js canary	ijjk/next.js fix/next-external-check	Change
_app-HASH.js gzip	1.02 kB	1.02 kB	✓
_error-HASH.js gzip	3.06 kB	3.06 kB	✓
amp-HASH.js gzip	526 B	526 B	✓
css-HASH.js gzip	334 B	334 B	✓
hooks-HASH.js gzip	890 B	890 B	✓
index-HASH.js gzip	262 B	262 B	✓
link-HASH.js gzip	1.65 kB	1.65 kB	✓
routerDirect..HASH.js gzip	331 B	331 B	✓
withRouter-HASH.js gzip	329 B	329 B	✓
bb14e60e810b..30f.css gzip	125 B	125 B	✓
Overall change	8.54 kB	8.54 kB	✓

Client Build Manifests

	vercel/next.js canary	ijjk/next.js fix/next-external-check	Change
_buildManifest.js gzip	390 B	390 B	✓
Overall change	390 B	390 B	✓

Serverless bundles

	vercel/next.js canary	ijjk/next.js fix/next-external-check	Change
_error.js	16.9 kB	16.9 kB	✓
404.html	2.42 kB	2.42 kB	✓
500.html	2.41 kB	2.41 kB	✓
amp.amp.html	10.8 kB	10.8 kB	✓
amp.html	1.61 kB	1.61 kB	✓
css.html	1.79 kB	1.79 kB	✓
hooks.html	1.67 kB	1.67 kB	✓
index.js	17.2 kB	17.2 kB	✓
link.js	17.4 kB	17.4 kB	✓
routerDirect.js	17.4 kB	17.4 kB	✓
withRouter.js	17.4 kB	17.4 kB	✓
Overall change	107 kB	107 kB	✓

---

Webpack 4 Mode (Increase detected ⚠️)

General Overall increase ⚠️

	vercel/next.js canary	ijjk/next.js fix/next-external-check	Change
buildDuration	10.7s	11s	⚠️ +259ms
buildDurationCached	5.2s	5s	-184ms
nodeModulesSize	46.7 MB	46.7 MB	⚠️ +422 B

Page Load Tests Overall increase ✓

	vercel/next.js canary	ijjk/next.js fix/next-external-check	Change
/ failed reqs	0	0	✓
/ total time (seconds)	2.301	2.273	-0.03
/ avg req/sec	1086.7	1099.71	+13.01
/error-in-render failed reqs	0	0	✓
/error-in-render total time (seconds)	1.316	1.26	-0.06
/error-in-render avg req/sec	1900.25	1984.74	+84.49

Client Bundles (main, webpack, commons)

	vercel/next.js canary	ijjk/next.js fix/next-external-check	Change
677f882d2ed8..HASH.js gzip	13.3 kB	13.3 kB	✓
framework.HASH.js gzip	39 kB	39 kB	✓
main-HASH.js gzip	7.25 kB	7.25 kB	✓
webpack-HASH.js gzip	751 B	751 B	✓
Overall change	60.3 kB	60.3 kB	✓

Legacy Client Bundles (polyfills)

	vercel/next.js canary	ijjk/next.js fix/next-external-check	Change
polyfills-HASH.js gzip	31.3 kB	31.3 kB	✓
Overall change	31.3 kB	31.3 kB	✓

Client Pages

	vercel/next.js canary	ijjk/next.js fix/next-external-check	Change
_app-HASH.js gzip	1.28 kB	1.28 kB	✓
_error-HASH.js gzip	3.74 kB	3.74 kB	✓
amp-HASH.js gzip	536 B	536 B	✓
css-HASH.js gzip	339 B	339 B	✓
hooks-HASH.js gzip	887 B	887 B	✓
index-HASH.js gzip	227 B	227 B	✓
link-HASH.js gzip	1.64 kB	1.64 kB	✓
routerDirect..HASH.js gzip	303 B	303 B	✓
withRouter-HASH.js gzip	302 B	302 B	✓
e025d2764813..52f.css gzip	125 B	125 B	✓
Overall change	9.38 kB	9.38 kB	✓

Client Build Manifests

	vercel/next.js canary	ijjk/next.js fix/next-external-check	Change
_buildManifest.js gzip	420 B	420 B	✓
Overall change	420 B	420 B	✓

Rendered Page Sizes

	vercel/next.js canary	ijjk/next.js fix/next-external-check	Change
index.html gzip	613 B	613 B	✓
link.html gzip	620 B	620 B	✓
withRouter.html gzip	606 B	606 B	✓
Overall change	1.84 kB	1.84 kB	✓

Commit: 0a9d7e3