Remove .only and ensure jest lint rules apply for all tests

[ijjk]

This removes a .only from a test and updates our .eslintrc config to ensure all test files have the jest rule applied so that we catch this automatically in the future. This also caught some duplicate tests in the production suite which are removed in this PR.

Bug

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

Feature

• Implements an existing feature request or RFC. Make sure the feature request has been accepted for implementation before opening a PR.
• Related issues linked using fixes #number
• Integration tests added
• Documentation added
• Telemetry added. In case of a feature if it's used or not.
• Errors have helpful link attached, see contributing.md

Documentation / Examples

• Make sure the linting passes by running yarn lint

[styfle]

Wonderful, thanks!

[ijjk]

Stats from current PR

Default Build (Increase detected ⚠️)

General Overall increase ⚠️

	vercel/next.js canary	ijjk/next.js test/remove-only	Change
buildDuration	23.1s	23.3s	⚠️ +198ms
buildDurationCached	4.5s	4.5s	⚠️ +6ms
nodeModulesSize	335 MB	335 MB	⚠️ +7 B

Page Load Tests Overall increase ✓

	vercel/next.js canary	ijjk/next.js test/remove-only	Change
/ failed reqs	0	0	✓
/ total time (seconds)	4.132	4.092	-0.04
/ avg req/sec	605.07	610.96	+5.89
/error-in-render failed reqs	0	0	✓
/error-in-render total time (seconds)	2.079	2.069	-0.01
/error-in-render avg req/sec	1202.5	1208.11	+5.61

Client Bundles (main, webpack, commons)

	vercel/next.js canary	ijjk/next.js test/remove-only	Change
450.HASH.js gzip	179 B	179 B	✓
framework-HASH.js gzip	42.2 kB	42.2 kB	✓
main-HASH.js gzip	28.3 kB	28.3 kB	✓
webpack-HASH.js gzip	1.45 kB	1.45 kB	✓
Overall change	72.2 kB	72.2 kB	✓

Legacy Client Bundles (polyfills)

	vercel/next.js canary	ijjk/next.js test/remove-only	Change
polyfills-HASH.js gzip	31 kB	31 kB	✓
Overall change	31 kB	31 kB	✓

Client Pages

	vercel/next.js canary	ijjk/next.js test/remove-only	Change
_app-HASH.js gzip	1.37 kB	1.37 kB	✓
_error-HASH.js gzip	194 B	194 B	✓
amp-HASH.js gzip	312 B	312 B	✓
css-HASH.js gzip	327 B	327 B	✓
dynamic-HASH.js gzip	2.38 kB	2.38 kB	✓
head-HASH.js gzip	350 B	350 B	✓
hooks-HASH.js gzip	635 B	635 B	✓
image-HASH.js gzip	4.44 kB	4.44 kB	✓
index-HASH.js gzip	263 B	263 B	✓
link-HASH.js gzip	1.87 kB	1.87 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	13.3 kB	13.3 kB	✓

Client Build Manifests

	vercel/next.js canary	ijjk/next.js test/remove-only	Change
_buildManifest.js gzip	460 B	460 B	✓
Overall change	460 B	460 B	✓

Rendered Page Sizes

	vercel/next.js canary	ijjk/next.js test/remove-only	Change
index.html gzip	523 B	523 B	✓
link.html gzip	536 B	536 B	✓
withRouter.html gzip	517 B	517 B	✓
Overall change	1.58 kB	1.58 kB	✓

---

Default Build with SWC (Decrease detected ✓)

General Overall increase ⚠️

	vercel/next.js canary	ijjk/next.js test/remove-only	Change
buildDuration	25.6s	25.5s	-49ms
buildDurationCached	4.7s	4.5s	-241ms
nodeModulesSize	335 MB	335 MB	⚠️ +7 B

Page Load Tests Overall decrease ⚠️

	vercel/next.js canary	ijjk/next.js test/remove-only	Change
/ failed reqs	0	0	✓
/ total time (seconds)	3.887	3.935	⚠️ +0.05
/ avg req/sec	643.14	635.32	⚠️ -7.82
/error-in-render failed reqs	0	0	✓
/error-in-render total time (seconds)	2.054	2.106	⚠️ +0.05
/error-in-render avg req/sec	1217.09	1187.12	⚠️ -29.97

Client Bundles (main, webpack, commons)

	vercel/next.js canary	ijjk/next.js test/remove-only	Change
450.HASH.js gzip	179 B	179 B	✓
framework-HASH.js gzip	42.3 kB	42.3 kB	✓
main-HASH.js gzip	28.6 kB	28.6 kB	✓
webpack-HASH.js gzip	1.44 kB	1.44 kB	✓
Overall change	72.5 kB	72.5 kB	✓

Legacy Client Bundles (polyfills)

	vercel/next.js canary	ijjk/next.js test/remove-only	Change
polyfills-HASH.js gzip	31 kB	31 kB	✓
Overall change	31 kB	31 kB	✓

Client Pages

	vercel/next.js canary	ijjk/next.js test/remove-only	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	2.38 kB	2.38 kB	✓
head-HASH.js gzip	342 B	342 B	✓
hooks-HASH.js gzip	622 B	622 B	✓
image-HASH.js gzip	4.46 kB	4.46 kB	✓
index-HASH.js gzip	256 B	256 B	✓
link-HASH.js gzip	1.91 kB	1.91 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	13.2 kB	13.2 kB	✓

Client Build Manifests

	vercel/next.js canary	ijjk/next.js test/remove-only	Change
_buildManifest.js gzip	460 B	460 B	✓
Overall change	460 B	460 B	✓

Rendered Page Sizes

	vercel/next.js canary	ijjk/next.js test/remove-only	Change
index.html gzip	523 B	523 B	✓
link.html gzip	535 B	535 B	✓
withRouter.html gzip	516 B	516 B	✓
Overall change	1.57 kB	1.57 kB	✓

Commit: 6991531