Move ImageResponse to next/og

[huozhi]

Story

Since we introduced ImageResponse into next/server export, there're a few libraries relying on next/server that accidentally ended up with bundling og image into the bundle. As og package is quite large that could easily raise the size concern for middleware, edge runtime routes.

Struggles

We've done optimizations. The tree-shaking strategies are tricky, we tried modularize imports and also optimize cjs require/exports to make sure you're not including og package into bundle if it's not being used. However, it's still not 100% can handle all the bundle optimization cases, such as import {..} from "next/server.js" could also ended up with the cjs bundle that failed the tree-shaking.

Move on

So we decide to move og ImageResponse into a separate export next/og

Closes NEXT-1660

[ijjk]

Stats from current PR

Default Build

General Overall increase ⚠️

	vercel/next.js canary	vercel/next.js migrate-og-export	Change
buildDuration	10.6s	10.6s	N/A
buildDurationCached	6.3s	6.3s	N/A
nodeModulesSize	175 MB	175 MB	⚠️ +2.82 kB
nextStartRea..uration (ms)	516ms	540ms	N/A

Client Bundles (main, webpack)

	vercel/next.js canary	vercel/next.js migrate-og-export	Change
199-HASH.js gzip	27.5 kB	27.5 kB	N/A
3f784ff6-HASH.js gzip	53.3 kB	53.3 kB	✓
99.HASH.js gzip	182 B	182 B	✓
framework-HASH.js gzip	45.3 kB	45.3 kB	✓
main-app-HASH.js gzip	254 B	250 B	N/A
main-HASH.js gzip	32.9 kB	32.9 kB	N/A
webpack-HASH.js gzip	1.75 kB	1.75 kB	N/A
Overall change	98.8 kB	98.8 kB	✓

Legacy Client Bundles (polyfills)

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

Client Pages

	vercel/next.js canary	vercel/next.js migrate-og-export	Change
_app-HASH.js gzip	206 B	205 B	N/A
_error-HASH.js gzip	182 B	180 B	N/A
amp-HASH.js gzip	506 B	505 B	N/A
css-HASH.js gzip	322 B	323 B	N/A
dynamic-HASH.js gzip	2.57 kB	2.57 kB	N/A
edge-ssr-HASH.js gzip	260 B	259 B	N/A
head-HASH.js gzip	350 B	350 B	✓
hooks-HASH.js gzip	369 B	369 B	✓
image-HASH.js gzip	4.36 kB	4.36 kB	N/A
index-HASH.js gzip	256 B	256 B	✓
link-HASH.js gzip	2.64 kB	2.63 kB	N/A
routerDirect..HASH.js gzip	312 B	311 B	N/A
script-HASH.js gzip	385 B	384 B	N/A
withRouter-HASH.js gzip	307 B	308 B	N/A
1afbb74e6ecf..834.css gzip	106 B	106 B	✓
Overall change	1.08 kB	1.08 kB	✓

Client Build Manifests

	vercel/next.js canary	vercel/next.js migrate-og-export	Change
_buildManifest.js gzip	484 B	482 B	N/A
Overall change	0 B	0 B	✓

Rendered Page Sizes

	vercel/next.js canary	vercel/next.js migrate-og-export	Change
index.html gzip	530 B	529 B	N/A
link.html gzip	542 B	542 B	✓
withRouter.html gzip	524 B	524 B	✓
Overall change	1.07 kB	1.07 kB	✓

Edge SSR bundle Size

	vercel/next.js canary	vercel/next.js migrate-og-export	Change
edge-ssr.js gzip	93.7 kB	93.7 kB	N/A
page.js gzip	155 kB	155 kB	N/A
Overall change	0 B	0 B	✓

Middleware size

	vercel/next.js canary	vercel/next.js migrate-og-export	Change
middleware-b..fest.js gzip	623 B	621 B	N/A
middleware-r..fest.js gzip	150 B	151 B	N/A
middleware.js gzip	22.5 kB	22.5 kB	N/A
edge-runtime..pack.js gzip	1.92 kB	1.92 kB	✓
Overall change	1.92 kB	1.92 kB	✓

Commit: 2e72835

[ijjk]

Tests Passed

[sokra]

next_import_map.rs need to have the alias updated too0

[styfle]

Docs need to be updated too:

https://nextjs.org/docs/app/api-reference/functions/image-response