refactor(build): no force transpile optional chaining

[SukkaW]

• Make sure the linting passes by running yarn lint

Ref:

• Unexpected token error at code with optional chaining when using Typescript webpack/webpack#10227
• [9.5.4-canary.20] default loader doesn't transpile nullish coalescing and optional chaining #17273
• Ensure optional-chaining/nullish coalescing is included #17429
• Ensure optional chaining in swc matches babel #33995
• Optional chain is incorrectly removed when used on import webpack/webpack#12960
• [regression] next throws away my optional chaining and gives me a prerender error instead #33915
• Ensure optional chaining in swc matches babel #33995
• update webpack #35867

Previously, webpack has some serious issues processing optional chaining (webpack/webpack#10227 which is fixed in webpack 5, and webpack/webpack#12960 which is fixed in webpack 5.71.0). The issues are also being reported to Next.js (#17273 which is fixed by #17429, and #33915 which is fixed by #33995).

With Next.js has deprecated Webpack 4 since this major version and has updated Webpack to 5.71.0 (#35867), it is now safe to remove force transpilation of optional chaining and nullish operator.

[ijjk]

Stats from current PR

Default Build (Decrease detected ✓)

General Overall decrease ✓

	vercel/next.js canary	SukkaW/next.js disable-nullish-optional-chain-transform	Change
buildDuration	20s	19.7s	-319ms
buildDurationCached	7.6s	7.5s	-37ms
nodeModulesSize	485 MB	485 MB	-1.17 kB

Page Load Tests Overall decrease ⚠️

	vercel/next.js canary	SukkaW/next.js disable-nullish-optional-chain-transform	Change
/ failed reqs	0	0	✓
/ total time (seconds)	4.22	4.271	⚠️ +0.05
/ avg req/sec	592.48	585.38	⚠️ -7.1
/error-in-render failed reqs	0	0	✓
/error-in-render total time (seconds)	2.052	2.108	⚠️ +0.06
/error-in-render avg req/sec	1218.59	1185.8	⚠️ -32.79

Client Bundles (main, webpack)

	vercel/next.js canary	SukkaW/next.js disable-nullish-optional-chain-transform	Change
925.HASH.js gzip	179 B	179 B	✓
framework-HASH.js gzip	42 kB	42 kB	✓
main-HASH.js gzip	28.3 kB	28.3 kB	✓
webpack-HASH.js gzip	1.44 kB	1.44 kB	✓
Overall change	72 kB	72 kB	✓

Legacy Client Bundles (polyfills)

	vercel/next.js canary	SukkaW/next.js disable-nullish-optional-chain-transform	Change
polyfills-HASH.js gzip	31 kB	31 kB	✓
Overall change	31 kB	31 kB	✓

Client Pages

	vercel/next.js canary	SukkaW/next.js disable-nullish-optional-chain-transform	Change
_app-HASH.js gzip	1.36 kB	1.36 kB	✓
_error-HASH.js gzip	192 B	192 B	✓
amp-HASH.js gzip	309 B	309 B	✓
css-HASH.js gzip	327 B	327 B	✓
dynamic-HASH.js gzip	3.04 kB	3.04 kB	✓
head-HASH.js gzip	351 B	351 B	✓
hooks-HASH.js gzip	920 B	920 B	✓
image-HASH.js gzip	5.74 kB	5.74 kB	✓
index-HASH.js gzip	263 B	263 B	✓
link-HASH.js gzip	2.36 kB	2.36 kB	✓
routerDirect..HASH.js gzip	320 B	320 B	✓
script-HASH.js gzip	392 B	392 B	✓
withRouter-HASH.js gzip	319 B	319 B	✓
85e02e95b279..7e3.css gzip	107 B	107 B	✓
Overall change	16 kB	16 kB	✓

Client Build Manifests

	vercel/next.js canary	SukkaW/next.js disable-nullish-optional-chain-transform	Change
_buildManifest.js gzip	461 B	461 B	✓
Overall change	461 B	461 B	✓

Rendered Page Sizes

	vercel/next.js canary	SukkaW/next.js disable-nullish-optional-chain-transform	Change
index.html gzip	530 B	530 B	✓
link.html gzip	544 B	544 B	✓
withRouter.html gzip	524 B	524 B	✓
Overall change	1.6 kB	1.6 kB	✓

---

Default Build with SWC (Decrease detected ✓)

General Overall decrease ✓

	vercel/next.js canary	SukkaW/next.js disable-nullish-optional-chain-transform	Change
buildDuration	22.9s	23.1s	⚠️ +171ms
buildDurationCached	7.5s	7.4s	-88ms
nodeModulesSize	485 MB	485 MB	-1.17 kB

Page Load Tests Overall decrease ⚠️

	vercel/next.js canary	SukkaW/next.js disable-nullish-optional-chain-transform	Change
/ failed reqs	0	0	✓
/ total time (seconds)	4.238	4.276	⚠️ +0.04
/ avg req/sec	589.85	584.6	⚠️ -5.25
/error-in-render failed reqs	0	0	✓
/error-in-render total time (seconds)	2.058	2.063	⚠️ +0.01
/error-in-render avg req/sec	1214.86	1211.69	⚠️ -3.17

Client Bundles (main, webpack)

	vercel/next.js canary	SukkaW/next.js disable-nullish-optional-chain-transform	Change
925.HASH.js gzip	178 B	178 B	✓
framework-HASH.js gzip	42.3 kB	42.3 kB	✓
main-HASH.js gzip	28.7 kB	28.7 kB	✓
webpack-HASH.js gzip	1.45 kB	1.45 kB	✓
Overall change	72.6 kB	72.6 kB	✓

Legacy Client Bundles (polyfills)

	vercel/next.js canary	SukkaW/next.js disable-nullish-optional-chain-transform	Change
polyfills-HASH.js gzip	31 kB	31 kB	✓
Overall change	31 kB	31 kB	✓

Client Pages

	vercel/next.js canary	SukkaW/next.js disable-nullish-optional-chain-transform	Change
_app-HASH.js gzip	1.35 kB	1.35 kB	✓
_error-HASH.js gzip	179 B	179 B	✓
amp-HASH.js gzip	313 B	313 B	✓
css-HASH.js gzip	325 B	325 B	✓
dynamic-HASH.js gzip	3.02 kB	3.02 kB	✓
head-HASH.js gzip	351 B	351 B	✓
hooks-HASH.js gzip	921 B	921 B	✓
image-HASH.js gzip	5.78 kB	5.78 kB	✓
index-HASH.js gzip	261 B	261 B	✓
link-HASH.js gzip	2.44 kB	2.44 kB	✓
routerDirect..HASH.js gzip	322 B	322 B	✓
script-HASH.js gzip	393 B	393 B	✓
withRouter-HASH.js gzip	317 B	317 B	✓
85e02e95b279..7e3.css gzip	107 B	107 B	✓
Overall change	16.1 kB	16.1 kB	✓

Client Build Manifests

	vercel/next.js canary	SukkaW/next.js disable-nullish-optional-chain-transform	Change
_buildManifest.js gzip	457 B	457 B	✓
Overall change	457 B	457 B	✓

Rendered Page Sizes

	vercel/next.js canary	SukkaW/next.js disable-nullish-optional-chain-transform	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	✓

Commit: b028d7e

[timneutkens]

Is optional chaining still downleveled when the targeted level doesn't support it? If that's the case these changes look fine.

[SukkaW]

Is optional chaining still downleveled when the targeted level doesn't support it? If that's the case these changes look fine.

@timneutkens Check test/integration/optional-chaining-nullish-coalescing. If that integrated test case passed, then it is fine.

[ijjk]

This change looks alright now as the test added in #33995 is passing against Node.js v16 and v17 which is what the affected versions were. I think it would be good to keep the unit tests though

[SukkaW]

This change looks alright now as the test added in #33995 is passing against Node.js v16 and v17 which is what the affected versions were. I think it would be good to keep the unit tests though

@ijjk

Next.js 12 requires a minimum Node.js version of 12.22.0, which doesn't support optional chaining syntax. And the CI runs tests on Node.js 16 & 17 which both have optional chaining syntax support. Thus the emitted code will be inconsistent against different Node.js versions.

IMHO the behavior should be tested by swc and babel (whether they can identify and apply transpilation), not by Next.js.