Simplify concurrent features related configurations and fix tests

[huozhi]

• Address some left comments from Add new target for middleware #30299
• Fix tests with webpack magic comments when concurrentFeatures set to true

[shuding]

Looks great!

[ijjk]

Failing test suites

Commit: 4a7314c

test/integration/create-next-app/index.test.js

• create next app > empty directory
• create next app > should support typescript flag
• create next app > should allow an example named default
• create next app > should ask the user for a name for the project if none supplied

Expand output

● create next app › empty directory

thrown: "Exceeded timeout of 90000 ms for a test.
Use jest.setTimeout(newTimeout) to increase the timeout value, if this is a long-running test."

  39 |   // stdin is piped instead of inherited on windows
  40 |   if (process.platform !== 'win32') {
> 41 |     it('empty directory', async () => {
     |     ^
  42 |       await usingTempDir(async (cwd) => {
  43 |         const projectName = 'empty-directory'
  44 |         const res = await run([projectName], { cwd })

  at integration/create-next-app/index.test.js:41:5
  at Object.<anonymous> (integration/create-next-app/index.test.js:24:1)

● create next app › should support typescript flag

thrown: "Exceeded timeout of 90000 ms for a test.
Use jest.setTimeout(newTimeout) to increase the timeout value, if this is a long-running test."

   99 |   })
  100 |
> 101 |   it('should support typescript flag', async () => {
      |   ^
  102 |     await usingTempDir(async (cwd) => {
  103 |       const projectName = 'typescript'
  104 |       const res = await run([projectName, '--typescript'], { cwd })

  at integration/create-next-app/index.test.js:101:3
  at Object.<anonymous> (integration/create-next-app/index.test.js:24:1)

● create next app › should allow an example named default

thrown: "Exceeded timeout of 90000 ms for a test.
Use jest.setTimeout(newTimeout) to increase the timeout value, if this is a long-running test."

  263 |   }
  264 |
> 265 |   it('should allow an example named default', async () => {
      |   ^
  266 |     await usingTempDir(async (cwd) => {
  267 |       const projectName = 'default-example'
  268 |       const res = await run([projectName, '--example', 'default'], { cwd })

  at integration/create-next-app/index.test.js:265:3
  at Object.<anonymous> (integration/create-next-app/index.test.js:24:1)

● create next app › should ask the user for a name for the project if none supplied

thrown: "Exceeded timeout of 90000 ms for a test.
Use jest.setTimeout(newTimeout) to increase the timeout value, if this is a long-running test."

  330 |   })
  331 |
> 332 |   it('should ask the user for a name for the project if none supplied', async () => {
      |   ^
  333 |     await usingTempDir(async (cwd) => {
  334 |       const projectName = 'test-project'
  335 |       const res = await run([], { cwd, input: `${projectName}\n` })

  at integration/create-next-app/index.test.js:332:3
  at Object.<anonymous> (integration/create-next-app/index.test.js:24:1)

[ijjk]

Stats from current PR

Default Build (Decrease detected ✓)

General Overall decrease ✓

	vercel/next.js canary	huozhi/next.js jc/1058a	Change
buildDuration	17.3s	17.3s	-43ms
buildDurationCached	3.5s	3.6s	⚠️ +48ms
nodeModulesSize	198 MB	198 MB	-897 B

Page Load Tests Overall decrease ⚠️

	vercel/next.js canary	huozhi/next.js jc/1058a	Change
/ failed reqs	0	0	✓
/ total time (seconds)	2.908	2.906	0
/ avg req/sec	859.79	860.42	+0.63
/error-in-render failed reqs	0	0	✓
/error-in-render total time (seconds)	1.34	1.409	⚠️ +0.07
/error-in-render avg req/sec	1866.36	1773.94	⚠️ -92.42

Client Bundles (main, webpack, commons)

	vercel/next.js canary	huozhi/next.js jc/1058a	Change
450.HASH.js gzip	179 B	179 B	✓
framework-HASH.js gzip	42.2 kB	42.2 kB	✓
main-HASH.js gzip	28 kB	28 kB	✓
webpack-HASH.js gzip	1.45 kB	1.45 kB	✓
Overall change	71.9 kB	71.9 kB	✓

Legacy Client Bundles (polyfills)

	vercel/next.js canary	huozhi/next.js jc/1058a	Change
polyfills-a4..dd70.js gzip	31 kB	31 kB	✓
Overall change	31 kB	31 kB	✓

Client Pages

	vercel/next.js canary	huozhi/next.js jc/1058a	Change
_app-HASH.js gzip	1.23 kB	1.23 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	✓
334f979574ae..6f4.css gzip	106 B	106 B	✓
Overall change	13.1 kB	13.1 kB	✓

Client Build Manifests

	vercel/next.js canary	huozhi/next.js jc/1058a	Change
_buildManifest.js gzip	459 B	459 B	✓
Overall change	459 B	459 B	✓

Rendered Page Sizes

	vercel/next.js canary	huozhi/next.js jc/1058a	Change
index.html gzip	534 B	534 B	✓
link.html gzip	547 B	547 B	✓
withRouter.html gzip	527 B	527 B	✓
Overall change	1.61 kB	1.61 kB	✓

---

Default Build with SWC (Decrease detected ✓)

General Overall decrease ✓

	vercel/next.js canary	huozhi/next.js jc/1058a	Change
buildDuration	14.5s	14.6s	⚠️ +91ms
buildDurationCached	3.6s	3.6s	-5ms
nodeModulesSize	198 MB	198 MB	-897 B

Page Load Tests Overall decrease ⚠️

	vercel/next.js canary	huozhi/next.js jc/1058a	Change
/ failed reqs	0	0	✓
/ total time (seconds)	2.947	2.924	-0.02
/ avg req/sec	848.18	854.88	+6.7
/error-in-render failed reqs	0	0	✓
/error-in-render total time (seconds)	1.333	1.374	⚠️ +0.04
/error-in-render avg req/sec	1876.05	1818.99	⚠️ -57.06

Client Bundles (main, webpack, commons)

	vercel/next.js canary	huozhi/next.js jc/1058a	Change
450.HASH.js gzip	179 B	179 B	✓
framework-HASH.js gzip	42.3 kB	42.3 kB	✓
main-HASH.js gzip	28.2 kB	28.2 kB	✓
webpack-HASH.js gzip	1.43 kB	1.43 kB	✓
Overall change	72.1 kB	72.1 kB	✓

Legacy Client Bundles (polyfills)

	vercel/next.js canary	huozhi/next.js jc/1058a	Change
polyfills-a4..dd70.js gzip	31 kB	31 kB	✓
Overall change	31 kB	31 kB	✓

Client Pages

	vercel/next.js canary	huozhi/next.js jc/1058a	Change
_app-HASH.js gzip	1.22 kB	1.22 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	✓
334f979574ae..6f4.css gzip	106 B	106 B	✓
Overall change	13.1 kB	13.1 kB	✓

Client Build Manifests

	vercel/next.js canary	huozhi/next.js jc/1058a	Change
_buildManifest.js gzip	460 B	460 B	✓
Overall change	460 B	460 B	✓

Rendered Page Sizes

	vercel/next.js canary	huozhi/next.js jc/1058a	Change
index.html gzip	534 B	534 B	✓
link.html gzip	547 B	547 B	✓
withRouter.html gzip	528 B	528 B	✓
Overall change	1.61 kB	1.61 kB	✓

Commit: 7e31e1d