Ensure invalid request to static page is handled correctly

[ijjk]

This ensures we respond with 405 when a POST request is done to a static page since these pages aren't able to consume a POST request. Pages with getServerSideProps or getInitialProps can still handle POST requests as usual.

Bug

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

x-ref: slack thread

[styfle]

405 is correct, but do we need to consider this semver major?

[ijjk]

I don't think we need to make this a major as doing a POST to a static page is pretty much a no-op and this matches the behavior we have on Vercel.

[ijjk]

Stats from current PR

Default Build (Increase detected ⚠️)

General Overall increase ⚠️

	vercel/next.js canary	ijjk/next.js fix/static-post-status	Change
buildDuration	17.5s	18.4s	⚠️ +905ms
buildDurationCached	7.1s	7.2s	⚠️ +65ms
nodeModulesSize	359 MB	359 MB	⚠️ +1 kB

Page Load Tests Overall increase ✓

	vercel/next.js canary	ijjk/next.js fix/static-post-status	Change
/ failed reqs	0	0	✓
/ total time (seconds)	3.758	3.792	⚠️ +0.03
/ avg req/sec	665.19	659.2	⚠️ -5.99
/error-in-render failed reqs	0	0	✓
/error-in-render total time (seconds)	1.605	1.528	-0.08
/error-in-render avg req/sec	1557.67	1635.7	+78.03

Client Bundles (main, webpack, commons)

	vercel/next.js canary	ijjk/next.js fix/static-post-status	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	71.5 kB	71.5 kB	✓

Legacy Client Bundles (polyfills)

	vercel/next.js canary	ijjk/next.js fix/static-post-status	Change
polyfills-HASH.js gzip	31 kB	31 kB	✓
Overall change	31 kB	31 kB	✓

Client Pages

	vercel/next.js canary	ijjk/next.js fix/static-post-status	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	5.01 kB	5.01 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 fix/static-post-status	Change
_buildManifest.js gzip	459 B	459 B	✓
Overall change	459 B	459 B	✓

Rendered Page Sizes

	vercel/next.js canary	ijjk/next.js fix/static-post-status	Change
index.html gzip	532 B	532 B	✓
link.html gzip	545 B	545 B	✓
withRouter.html gzip	526 B	526 B	✓
Overall change	1.6 kB	1.6 kB	✓

---

Default Build with SWC (Decrease detected ✓)

General Overall increase ⚠️

	vercel/next.js canary	ijjk/next.js fix/static-post-status	Change
buildDuration	21.3s	21.8s	⚠️ +517ms
buildDurationCached	7.2s	7.2s	⚠️ +62ms
nodeModulesSize	359 MB	359 MB	⚠️ +1 kB

Page Load Tests Overall decrease ⚠️

	vercel/next.js canary	ijjk/next.js fix/static-post-status	Change
/ failed reqs	0	0	✓
/ total time (seconds)	3.76	3.495	-0.26
/ avg req/sec	664.93	715.31	+50.38
/error-in-render failed reqs	0	0	✓
/error-in-render total time (seconds)	1.562	1.618	⚠️ +0.06
/error-in-render avg req/sec	1600.43	1544.97	⚠️ -55.46

Client Bundles (main, webpack, commons)

	vercel/next.js canary	ijjk/next.js fix/static-post-status	Change
450.HASH.js gzip	179 B	179 B	✓
framework-HASH.js gzip	42.1 kB	42.1 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 fix/static-post-status	Change
polyfills-HASH.js gzip	31 kB	31 kB	✓
Overall change	31 kB	31 kB	✓

Client Pages

	vercel/next.js canary	ijjk/next.js fix/static-post-status	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	5.05 kB	5.05 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 fix/static-post-status	Change
_buildManifest.js gzip	458 B	458 B	✓
Overall change	458 B	458 B	✓

Rendered Page Sizes

	vercel/next.js canary	ijjk/next.js fix/static-post-status	Change
index.html gzip	533 B	533 B	✓
link.html gzip	546 B	546 B	✓
withRouter.html gzip	527 B	527 B	✓
Overall change	1.61 kB	1.61 kB	✓

Commit: d192fc1