fix(middleware): false positive dynamic code detection at build time

[feugy]

What's in there?

Partially fixes https://github.com/vercel/edge-functions/issues/82
Relates to #36715

Our webpack plugin for middleware leverages static analysis to detect Dyanamic code evaluation in user _middleware.js file (and depedencies). Since edge function runtime do not allow them, the build is aborted.

The use of Function.bind is considered invalid, while it is legit. A customer using @aws-sdk/client-s3 reported it.
This PR fixes it.

Please note that this check is too strict: some dynamic code may be in the bundle (despite treeshaking), but may never be used (because of code branches). Since this point is under discussion, this PR adds tests covering some false positives (@apollo/react-hook, qs and has), but does not change the behavior (consider them as errors).

Notes to reviewer

I looked for test facilities allowing to download the required 3rd party modules. createNext() in production context made my day, but showed two issues:

• cliOutput is not cleaned in between tests. While clearance during stop() would be annoying, I hope that clearance during start() is better.
• if start() fails while building, the created instance can never be stopped. This is because we don't clear childProcess after build.

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

[ijjk]

Stats from current PR

Default Build (Increase detected ⚠️)

General Overall decrease ✓

	vercel/next.js canary	feugy/next.js fix/false-positive-dynamic-code-detection	Change
buildDuration	15.6s	15.6s	-46ms
buildDurationCached	6.3s	6.2s	-128ms
nodeModulesSize	478 MB	478 MB	-372 B

Page Load Tests Overall increase ✓

	vercel/next.js canary	feugy/next.js fix/false-positive-dynamic-code-detection	Change
/ failed reqs	0	0	✓
/ total time (seconds)	3.876	3.78	-0.1
/ avg req/sec	645.01	661.31	+16.3
/error-in-render failed reqs	0	0	✓
/error-in-render total time (seconds)	1.365	1.278	-0.09
/error-in-render avg req/sec	1831.14	1956.93	+125.79

Client Bundles (main, webpack)

	vercel/next.js canary	feugy/next.js fix/false-positive-dynamic-code-detection	Change
925.HASH.js gzip	179 B	179 B	✓
framework-HASH.js gzip	42 kB	42 kB	✓
main-HASH.js gzip	28.7 kB	28.7 kB	✓
webpack-HASH.js gzip	1.44 kB	1.44 kB	✓
Overall change	72.4 kB	72.4 kB	✓

Legacy Client Bundles (polyfills)

	vercel/next.js canary	feugy/next.js fix/false-positive-dynamic-code-detection	Change
polyfills-HASH.js gzip	31 kB	31 kB	✓
Overall change	31 kB	31 kB	✓

Client Pages

	vercel/next.js canary	feugy/next.js fix/false-positive-dynamic-code-detection	Change
_app-HASH.js gzip	1.36 kB	1.36 kB	✓
_error-HASH.js gzip	193 B	193 B	✓
amp-HASH.js gzip	308 B	308 B	✓
css-HASH.js gzip	327 B	327 B	✓
dynamic-HASH.js gzip	2.7 kB	2.7 kB	✓
head-HASH.js gzip	359 B	359 B	✓
hooks-HASH.js gzip	920 B	920 B	✓
image-HASH.js gzip	5.71 kB	5.71 kB	✓
index-HASH.js gzip	263 B	263 B	✓
link-HASH.js gzip	2.65 kB	2.65 kB	✓
routerDirect..HASH.js gzip	320 B	320 B	✓
script-HASH.js gzip	391 B	391 B	✓
withRouter-HASH.js gzip	318 B	318 B	✓
85e02e95b279..7e3.css gzip	107 B	107 B	✓
Overall change	15.9 kB	15.9 kB	✓

Client Build Manifests

	vercel/next.js canary	feugy/next.js fix/false-positive-dynamic-code-detection	Change
_buildManifest.js gzip	458 B	458 B	✓
Overall change	458 B	458 B	✓

Rendered Page Sizes

	vercel/next.js canary	feugy/next.js fix/false-positive-dynamic-code-detection	Change
index.html gzip	532 B	532 B	✓
link.html gzip	544 B	544 B	✓
withRouter.html gzip	528 B	528 B	✓
Overall change	1.6 kB	1.6 kB	✓

---

Default Build with SWC (Increase detected ⚠️)

General Overall decrease ✓

	vercel/next.js canary	feugy/next.js fix/false-positive-dynamic-code-detection	Change
buildDuration	17.5s	17.6s	⚠️ +92ms
buildDurationCached	6.3s	5.9s	-430ms
nodeModulesSize	478 MB	478 MB	-372 B

Page Load Tests Overall increase ✓

	vercel/next.js canary	feugy/next.js fix/false-positive-dynamic-code-detection	Change
/ failed reqs	0	0	✓
/ total time (seconds)	3.847	3.68	-0.17
/ avg req/sec	649.87	679.35	+29.48
/error-in-render failed reqs	0	0	✓
/error-in-render total time (seconds)	1.317	1.257	-0.06
/error-in-render avg req/sec	1898.61	1989.25	+90.64

Client Bundles (main, webpack)

	vercel/next.js canary	feugy/next.js fix/false-positive-dynamic-code-detection	Change
925.HASH.js gzip	178 B	178 B	✓
framework-HASH.js gzip	42.7 kB	42.7 kB	✓
main-HASH.js gzip	29.2 kB	29.2 kB	✓
webpack-HASH.js gzip	1.45 kB	1.45 kB	✓
Overall change	73.5 kB	73.5 kB	✓

Legacy Client Bundles (polyfills)

	vercel/next.js canary	feugy/next.js fix/false-positive-dynamic-code-detection	Change
polyfills-HASH.js gzip	31 kB	31 kB	✓
Overall change	31 kB	31 kB	✓

Client Pages

	vercel/next.js canary	feugy/next.js fix/false-positive-dynamic-code-detection	Change
_app-HASH.js gzip	1.35 kB	1.35 kB	✓
_error-HASH.js gzip	179 B	179 B	✓
amp-HASH.js gzip	311 B	311 B	✓
css-HASH.js gzip	324 B	324 B	✓
dynamic-HASH.js gzip	2.89 kB	2.89 kB	✓
head-HASH.js gzip	357 B	357 B	✓
hooks-HASH.js gzip	920 B	920 B	✓
image-HASH.js gzip	5.8 kB	5.8 kB	✓
index-HASH.js gzip	261 B	261 B	✓
link-HASH.js gzip	2.77 kB	2.77 kB	✓
routerDirect..HASH.js gzip	322 B	322 B	✓
script-HASH.js gzip	392 B	392 B	✓
withRouter-HASH.js gzip	317 B	317 B	✓
85e02e95b279..7e3.css gzip	107 B	107 B	✓
Overall change	16.3 kB	16.3 kB	✓

Client Build Manifests

	vercel/next.js canary	feugy/next.js fix/false-positive-dynamic-code-detection	Change
_buildManifest.js gzip	457 B	457 B	✓
Overall change	457 B	457 B	✓

Rendered Page Sizes

	vercel/next.js canary	feugy/next.js fix/false-positive-dynamic-code-detection	Change
index.html gzip	532 B	532 B	✓
link.html gzip	547 B	547 B	✓
withRouter.html gzip	528 B	528 B	✓
Overall change	1.61 kB	1.61 kB	✓

Commit: 94797e8