Add warning during next build when sharp is missing

[styfle]

Follow up to #27346

[ijjk]

Failing test suites

Commit: 98b7e5c

test/integration/image-optimizer/test/index.test.js

• Image Optimizer > with sharp > Server support w/o next.config.js > should not have build warning when sharp is installed
• Image Optimizer > with sharp > Server support with next.config.js > should not have build warning when sharp is installed

Expand output

● Image Optimizer › with sharp › Server support w/o next.config.js › should not have build warning when sharp is installed

expect(received).not.toContain(expected) // indexOf

Expected substring: not "Detected `next/image` usage without `sharp`."
Received string:        "warn  - Detected next.config.js, no exported configuration found. https://nextjs.org/docs/messages/empty-configuration
warn  - Detected `next/image` usage without `sharp`. https://nextjs.org/docs/messages/sharp-missing-in-production
"

  742 |
  743 |     it('should not have build warning when sharp is installed', () => {
> 744 |       expect(buildOutput).not.toContain(sharpBuildWarning)
      |                               ^
  745 |     })
  746 |   } else {
  747 |     it('should have runtime warning when sharp is not installed', () => {

  at Object.<anonymous> (integration/image-optimizer/test/index.test.js:744:31)

● Image Optimizer › with sharp › Server support with next.config.js › should not have build warning when sharp is installed

expect(received).not.toContain(expected) // indexOf

Expected substring: not "Detected `next/image` usage without `sharp`."
Received string:        "warn  - Detected `next/image` usage without `sharp`. https://nextjs.org/docs/messages/sharp-missing-in-production
"

  742 |
  743 |     it('should not have build warning when sharp is installed', () => {
> 744 |       expect(buildOutput).not.toContain(sharpBuildWarning)
      |                               ^
  745 |     })
  746 |   } else {
  747 |     it('should have runtime warning when sharp is not installed', () => {

  at Object.<anonymous> (integration/image-optimizer/test/index.test.js:744:31)

[ijjk]

Stats from current PR

Default Build (Increase detected ⚠️)

General Overall increase ⚠️

	vercel/next.js canary	vercel/next.js add-sharp-warning-next-build	Change
buildDuration	15.4s	15.4s	⚠️ +9ms
buildDurationCached	3.6s	3.6s	⚠️ +14ms
nodeModulesSize	49.1 MB	49.1 MB	⚠️ +1.4 kB

Page Load Tests Overall increase ✓

	vercel/next.js canary	vercel/next.js add-sharp-warning-next-build	Change
/ failed reqs	0	0	✓
/ total time (seconds)	2.831	2.873	⚠️ +0.04
/ avg req/sec	883.11	870.09	⚠️ -13.02
/error-in-render failed reqs	0	0	✓
/error-in-render total time (seconds)	1.852	1.782	-0.07
/error-in-render avg req/sec	1349.9	1402.58	+52.68

Client Bundles (main, webpack, commons)

	vercel/next.js canary	vercel/next.js add-sharp-warning-next-build	Change
745.HASH.js gzip	179 B	179 B	✓
framework-HASH.js gzip	42.2 kB	42.2 kB	✓
main-HASH.js gzip	23.1 kB	23.1 kB	✓
webpack-HASH.js gzip	1.5 kB	1.5 kB	✓
Overall change	67 kB	67 kB	✓

Legacy Client Bundles (polyfills)

	vercel/next.js canary	vercel/next.js add-sharp-warning-next-build	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	vercel/next.js add-sharp-warning-next-build	Change
_app-HASH.js gzip	980 B	980 B	✓
_error-HASH.js gzip	194 B	194 B	✓
amp-HASH.js gzip	312 B	312 B	✓
css-HASH.js gzip	329 B	329 B	✓
dynamic-HASH.js gzip	2.52 kB	2.52 kB	✓
head-HASH.js gzip	350 B	350 B	✓
hooks-HASH.js gzip	904 B	904 B	✓
image-HASH.js gzip	4.13 kB	4.13 kB	✓
index-HASH.js gzip	261 B	261 B	✓
link-HASH.js gzip	1.66 kB	1.66 kB	✓
routerDirect..HASH.js gzip	319 B	319 B	✓
script-HASH.js gzip	387 B	387 B	✓
withRouter-HASH.js gzip	320 B	320 B	✓
bb14e60e810b..30f.css gzip	125 B	125 B	✓
Overall change	12.8 kB	12.8 kB	✓

Client Build Manifests

	vercel/next.js canary	vercel/next.js add-sharp-warning-next-build	Change
_buildManifest.js gzip	491 B	491 B	✓
Overall change	491 B	491 B	✓

Rendered Page Sizes

	vercel/next.js canary	vercel/next.js add-sharp-warning-next-build	Change
index.html gzip	531 B	531 B	✓
link.html gzip	544 B	544 B	✓
withRouter.html gzip	523 B	523 B	✓
Overall change	1.6 kB	1.6 kB	✓

---

Webpack 4 Mode (Decrease detected ✓)

General Overall increase ⚠️

	vercel/next.js canary	vercel/next.js add-sharp-warning-next-build	Change
buildDuration	12.9s	12.6s	-354ms
buildDurationCached	5.1s	4.9s	-211ms
nodeModulesSize	49.1 MB	49.1 MB	⚠️ +1.4 kB

Page Load Tests Overall decrease ⚠️

	vercel/next.js canary	vercel/next.js add-sharp-warning-next-build	Change
/ failed reqs	0	0	✓
/ total time (seconds)	2.879	2.923	⚠️ +0.04
/ avg req/sec	868.38	855.35	⚠️ -13.03
/error-in-render failed reqs	0	0	✓
/error-in-render total time (seconds)	1.782	1.851	⚠️ +0.07
/error-in-render avg req/sec	1402.97	1350.37	⚠️ -52.6

Client Bundles (main, webpack, commons)

	vercel/next.js canary	vercel/next.js add-sharp-warning-next-build	Change
17.HASH.js gzip	185 B	185 B	✓
677f882d2ed8..HASH.js gzip	14 kB	14 kB	✓
framework.HASH.js gzip	41.9 kB	41.9 kB	✓
main-HASH.js gzip	10.6 kB	10.6 kB	✓
webpack-HASH.js gzip	1.19 kB	1.19 kB	✓
Overall change	67.9 kB	67.9 kB	✓

Legacy Client Bundles (polyfills)

	vercel/next.js canary	vercel/next.js add-sharp-warning-next-build	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	vercel/next.js add-sharp-warning-next-build	Change
_app-HASH.js gzip	965 B	965 B	✓
_error-HASH.js gzip	3.71 kB	3.71 kB	✓
amp-HASH.js gzip	552 B	552 B	✓
css-HASH.js gzip	333 B	333 B	✓
dynamic-HASH.js gzip	2.71 kB	2.71 kB	✓
head-HASH.js gzip	2.97 kB	2.97 kB	✓
hooks-HASH.js gzip	911 B	911 B	✓
index-HASH.js gzip	231 B	231 B	✓
link-HASH.js gzip	1.64 kB	1.64 kB	✓
routerDirect..HASH.js gzip	298 B	298 B	✓
script-HASH.js gzip	2.95 kB	2.95 kB	✓
withRouter-HASH.js gzip	294 B	294 B	✓
e025d2764813..52f.css gzip	125 B	125 B	✓
Overall change	17.7 kB	17.7 kB	✓

Client Build Manifests

	vercel/next.js canary	vercel/next.js add-sharp-warning-next-build	Change
_buildManifest.js gzip	498 B	498 B	✓
Overall change	498 B	498 B	✓

Rendered Page Sizes

	vercel/next.js canary	vercel/next.js add-sharp-warning-next-build	Change
index.html gzip	577 B	577 B	✓
link.html gzip	589 B	589 B	✓
withRouter.html gzip	570 B	570 B	✓
Overall change	1.74 kB	1.74 kB	✓

Commit: aa5df37