Update server-only changes HMR handling

[ijjk]

This updates to ensure we track server only changes correctly as previously we were relying on the chunk.hash value from webpack which doesn't seem to be reliable for this case. Failing tests were tested in #34396 (comment) to ensure we don't regress on this.

Bug

• Related issues linked using fixes #number
• Integration tests added
• Errors have helpful link attached, see contributing.md

Fixes: #19230
x-ref: slack thread
x-ref: #34054

[ijjk]

Stats from current PR

Default Build (Decrease detected ✓)

General Overall increase ⚠️

	vercel/next.js canary	ijjk/next.js update/ssr-changes-tracking	Change
buildDuration	16.3s	16s	-290ms
buildDurationCached	6.2s	6.2s	⚠️ +22ms
nodeModulesSize	359 MB	359 MB	⚠️ +2.69 kB

Page Load Tests Overall decrease ⚠️

	vercel/next.js canary	ijjk/next.js update/ssr-changes-tracking	Change
/ failed reqs	0	0	✓
/ total time (seconds)	3.302	3.344	⚠️ +0.04
/ avg req/sec	757.13	747.56	⚠️ -9.57
/error-in-render failed reqs	0	0	✓
/error-in-render total time (seconds)	1.439	1.459	⚠️ +0.02
/error-in-render avg req/sec	1736.8	1713.78	⚠️ -23.02

Client Bundles (main, webpack, commons)

	vercel/next.js canary	ijjk/next.js update/ssr-changes-tracking	Change
450.HASH.js gzip	179 B	179 B	✓
framework-HASH.js gzip	42 kB	42 kB	✓
main-HASH.js gzip	27.9 kB	27.9 kB	✓
webpack-HASH.js gzip	1.44 kB	1.44 kB	✓
Overall change	71.6 kB	71.6 kB	✓

Legacy Client Bundles (polyfills)

	vercel/next.js canary	ijjk/next.js update/ssr-changes-tracking	Change
polyfills-HASH.js gzip	31 kB	31 kB	✓
Overall change	31 kB	31 kB	✓

Client Pages

	vercel/next.js canary	ijjk/next.js update/ssr-changes-tracking	Change
_app-HASH.js gzip	1.36 kB	1.36 kB	✓
_error-HASH.js gzip	194 B	194 B	✓
amp-HASH.js gzip	312 B	312 B	✓
css-HASH.js gzip	326 B	326 B	✓
dynamic-HASH.js gzip	2.57 kB	2.57 kB	✓
head-HASH.js gzip	350 B	350 B	✓
hooks-HASH.js gzip	919 B	919 B	✓
image-HASH.js gzip	5.04 kB	5.04 kB	✓
index-HASH.js gzip	263 B	263 B	✓
link-HASH.js gzip	2.26 kB	2.26 kB	✓
routerDirect..HASH.js gzip	321 B	321 B	✓
script-HASH.js gzip	383 B	383 B	✓
withRouter-HASH.js gzip	318 B	318 B	✓
85e02e95b279..7e3.css gzip	107 B	107 B	✓
Overall change	14.7 kB	14.7 kB	✓

Client Build Manifests

	vercel/next.js canary	ijjk/next.js update/ssr-changes-tracking	Change
_buildManifest.js gzip	458 B	458 B	✓
Overall change	458 B	458 B	✓

Rendered Page Sizes

	vercel/next.js canary	ijjk/next.js update/ssr-changes-tracking	Change
index.html gzip	532 B	532 B	✓
link.html gzip	544 B	544 B	✓
withRouter.html gzip	527 B	527 B	✓
Overall change	1.6 kB	1.6 kB	✓

---

Default Build with SWC (Increase detected ⚠️)

General Overall increase ⚠️

	vercel/next.js canary	ijjk/next.js update/ssr-changes-tracking	Change
buildDuration	18.8s	18s	-851ms
buildDurationCached	6s	5.8s	-148ms
nodeModulesSize	359 MB	359 MB	⚠️ +2.69 kB

Page Load Tests Overall increase ✓

	vercel/next.js canary	ijjk/next.js update/ssr-changes-tracking	Change
/ failed reqs	0	0	✓
/ total time (seconds)	3.231	3.199	-0.03
/ avg req/sec	773.74	781.54	+7.8
/error-in-render failed reqs	0	0	✓
/error-in-render total time (seconds)	1.407	1.325	-0.08
/error-in-render avg req/sec	1776.81	1886.97	+110.16

Client Bundles (main, webpack, commons)

	vercel/next.js canary	ijjk/next.js update/ssr-changes-tracking	Change
450.HASH.js gzip	179 B	179 B	✓
framework-HASH.js gzip	42.1 kB	42.1 kB	✓
main-HASH.js gzip	28 kB	28 kB	✓
webpack-HASH.js gzip	1.44 kB	1.44 kB	✓
Overall change	71.7 kB	71.7 kB	✓

Legacy Client Bundles (polyfills)

	vercel/next.js canary	ijjk/next.js update/ssr-changes-tracking	Change
polyfills-HASH.js gzip	31 kB	31 kB	✓
Overall change	31 kB	31 kB	✓

Client Pages

	vercel/next.js canary	ijjk/next.js update/ssr-changes-tracking	Change
_app-HASH.js gzip	1.35 kB	1.35 kB	✓
_error-HASH.js gzip	180 B	180 B	✓
amp-HASH.js gzip	305 B	305 B	✓
css-HASH.js gzip	321 B	321 B	✓
dynamic-HASH.js gzip	2.56 kB	2.56 kB	✓
head-HASH.js gzip	342 B	342 B	✓
hooks-HASH.js gzip	911 B	911 B	✓
image-HASH.js gzip	5.08 kB	5.08 kB	✓
index-HASH.js gzip	256 B	256 B	✓
link-HASH.js gzip	2.28 kB	2.28 kB	✓
routerDirect..HASH.js gzip	314 B	314 B	✓
script-HASH.js gzip	375 B	375 B	✓
withRouter-HASH.js gzip	309 B	309 B	✓
85e02e95b279..7e3.css gzip	107 B	107 B	✓
Overall change	14.7 kB	14.7 kB	✓

Client Build Manifests

	vercel/next.js canary	ijjk/next.js update/ssr-changes-tracking	Change
_buildManifest.js gzip	459 B	459 B	✓
Overall change	459 B	459 B	✓

Rendered Page Sizes

	vercel/next.js canary	ijjk/next.js update/ssr-changes-tracking	Change
index.html gzip	534 B	534 B	✓
link.html gzip	547 B	547 B	✓
withRouter.html gzip	528 B	528 B	✓
Overall change	1.61 kB	1.61 kB	✓

Commit: f755cb3