Ensure error message prints next.config.mjs

[styfle]

This PR ensures we print the correct error message for either next.config.js or next.config.mjs, whichever was detected.

[ijjk]

Failing test suites

Commit: f443795

test/development/acceptance/ReactRefreshLogBox-builtins.test.ts

• ReactRefreshLogBox > Module not found (empty import trace)

Expand output

● ReactRefreshLogBox › Module not found (empty import trace)

expect(received).toMatchSnapshot()

Snapshot name: `ReactRefreshLogBox Module not found (empty import trace) 1`

- Snapshot  - 0
+ Received  + 2

@@ -3,6 +3,8 @@
  > 1 | import Comp from 'b'
    2 |       export default function Oops() {
    3 |         return (
    4 |           <div>

+ Import trace for requested module:
+
  https://nextjs.org/docs/messages/module-not-found

  73 |
  74 |     const source = await session.getRedboxSource()
> 75 |     expect(source).toMatchSnapshot()
     |                        ^
  76 |
  77 |     await cleanup()
  78 |   })

  at Object.<anonymous> (development/acceptance/ReactRefreshLogBox-builtins.test.ts:75:24)

[ijjk]

Stats from current PR

Default Build (Increase detected ⚠️)

General Overall increase ⚠️

	vercel/next.js canary	vercel/next.js ensure-error-message-next-config-mjs	Change
buildDuration	16.7s	16.8s	⚠️ +49ms
buildDurationCached	3.7s	3.7s	-10ms
nodeModulesSize	196 MB	196 MB	⚠️ +1.03 kB

Page Load Tests Overall increase ✓

	vercel/next.js canary	vercel/next.js ensure-error-message-next-config-mjs	Change
/ failed reqs	0	0	✓
/ total time (seconds)	3.966	3.919	-0.05
/ avg req/sec	630.33	637.89	+7.56
/error-in-render failed reqs	0	0	✓
/error-in-render total time (seconds)	2.243	2.219	-0.02
/error-in-render avg req/sec	1114.57	1126.47	+11.9

Client Bundles (main, webpack, commons)

	vercel/next.js canary	vercel/next.js ensure-error-message-next-config-mjs	Change
651.cd440d20..0b23.js gzip	2.96 kB	2.96 kB	✓
831.695e33f6..205f.js gzip	179 B	179 B	✓
framework-89..a097.js gzip	42.2 kB	42.2 kB	✓
main-2d2c447..b00a.js gzip	26.1 kB	26.1 kB	✓
webpack-f09b..493e.js gzip	1.47 kB	1.47 kB	✓
Overall change	73 kB	73 kB	✓

Legacy Client Bundles (polyfills)

	vercel/next.js canary	vercel/next.js ensure-error-message-next-config-mjs	Change
polyfills-a4..dd70.js gzip	31 kB	31 kB	✓
Overall change	31 kB	31 kB	✓

Client Pages

	vercel/next.js canary	vercel/next.js ensure-error-message-next-config-mjs	Change
_app-9fb8765..c13d.js gzip	979 B	979 B	✓
_error-d828d..2954.js gzip	3.06 kB	3.06 kB	✓
amp-5388d1f5..4ce9.js gzip	551 B	551 B	✓
css-10424225..367a.js gzip	329 B	329 B	✓
dynamic-9821..3cd4.js gzip	2.67 kB	2.67 kB	✓
head-1df323b..d261.js gzip	2.32 kB	2.32 kB	✓
hooks-ab0016..b093.js gzip	917 B	917 B	✓
image-c3cc30..4e2a.js gzip	5.87 kB	5.87 kB	✓
index-95c8cb..6970.js gzip	260 B	260 B	✓
link-05c99e7..35ec.js gzip	1.66 kB	1.66 kB	✓
routerDirect..6659.js gzip	319 B	319 B	✓
script-d94ba..ed05.js gzip	386 B	386 B	✓
withRouter-7..8b2e.js gzip	317 B	317 B	✓
9a34b27eb3f9..27d.css gzip	125 B	125 B	✓
Overall change	19.8 kB	19.8 kB	✓

Client Build Manifests

	vercel/next.js canary	vercel/next.js ensure-error-message-next-config-mjs	Change
_buildManifest.js gzip	458 B	458 B	✓
Overall change	458 B	458 B	✓

Rendered Page Sizes

	vercel/next.js canary	vercel/next.js ensure-error-message-next-config-mjs	Change
index.html gzip	536 B	536 B	✓
link.html gzip	548 B	548 B	✓
withRouter.html gzip	529 B	529 B	✓
Overall change	1.61 kB	1.61 kB	✓

---

Default Build with SWC (Decrease detected ✓)

General Overall increase ⚠️

	vercel/next.js canary	vercel/next.js ensure-error-message-next-config-mjs	Change
buildDuration	8.1s	7.9s	-210ms
buildDurationCached	3.7s	3.7s	⚠️ +41ms
nodeModulesSize	196 MB	196 MB	⚠️ +1.03 kB

Page Load Tests Overall decrease ⚠️

	vercel/next.js canary	vercel/next.js ensure-error-message-next-config-mjs	Change
/ failed reqs	0	0	✓
/ total time (seconds)	3.965	4	⚠️ +0.04
/ avg req/sec	630.47	625.04	⚠️ -5.43
/error-in-render failed reqs	0	0	✓
/error-in-render total time (seconds)	2.178	2.169	-0.01
/error-in-render avg req/sec	1147.89	1152.5	+4.61

Client Bundles (main, webpack, commons)

	vercel/next.js canary	vercel/next.js ensure-error-message-next-config-mjs	Change
450.fd3ad245..022b.js gzip	179 B	179 B	✓
675-228d3e2f..0c27.js gzip	13.8 kB	13.8 kB	✓
framework-13..70b0.js gzip	50.8 kB	50.8 kB	✓
main-3b9ef1a..94c9.js gzip	36.5 kB	36.5 kB	✓
webpack-a7f2..2650.js gzip	1.63 kB	1.63 kB	✓
Overall change	103 kB	103 kB	✓

Legacy Client Bundles (polyfills)

	vercel/next.js canary	vercel/next.js ensure-error-message-next-config-mjs	Change
polyfills-a4..dd70.js gzip	31 kB	31 kB	✓
Overall change	31 kB	31 kB	✓

Client Pages

	vercel/next.js canary	vercel/next.js ensure-error-message-next-config-mjs	Change
_app-ae91bc3..d985.js gzip	1.33 kB	1.33 kB	✓
_error-273ac..9ef0.js gzip	180 B	180 B	✓
amp-5f9a7694..99ce.js gzip	315 B	315 B	✓
css-3a1b2477..df1e.js gzip	330 B	330 B	✓
dynamic-e04a..a1b5.js gzip	2.79 kB	2.79 kB	✓
head-7f600d0..daa3.js gzip	356 B	356 B	✓
hooks-bd8c02..0730.js gzip	638 B	638 B	✓
image-16df09..4584.js gzip	555 B	555 B	✓
index-80be94..e89f.js gzip	262 B	262 B	✓
link-4ee1ea7..8745.js gzip	2.22 kB	2.22 kB	✓
routerDirect..c4aa.js gzip	325 B	325 B	✓
script-67da0..49e6.js gzip	390 B	390 B	✓
withRouter-2..2409.js gzip	322 B	322 B	✓
9a34b27eb3f9..27d.css gzip	125 B	125 B	✓
Overall change	10.1 kB	10.1 kB	✓

Client Build Manifests

	vercel/next.js canary	vercel/next.js ensure-error-message-next-config-mjs	Change
_buildManifest.js gzip	477 B	477 B	✓
Overall change	477 B	477 B	✓

Rendered Page Sizes

	vercel/next.js canary	vercel/next.js ensure-error-message-next-config-mjs	Change
index.html gzip	535 B	535 B	✓
link.html gzip	546 B	546 B	✓
withRouter.html gzip	526 B	526 B	✓
Overall change	1.61 kB	1.61 kB	✓

Commit: 35542fd