Add default trace format that is exported automatically

[timneutkens]

Allows for getting traces out of every next build to diagnose where time is spent.

This is a work in progress, implementation can/will change so don't rely on the output format.

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

[ijjk]

Stats from current PR

Default Build (Increase detected ⚠️)

General Overall increase ⚠️

	vercel/next.js canary	timneutkens/next.js add/json-traces	Change
buildDuration	15.9s	15.3s	-596ms
buildDurationCached	3.6s	3.2s	-468ms
nodeModulesSize	61.7 MB	61.7 MB	⚠️ +7.33 kB

Page Load Tests Overall increase ✓

	vercel/next.js canary	timneutkens/next.js add/json-traces	Change
/ failed reqs	0	0	✓
/ total time (seconds)	2.78	2.86	⚠️ +0.08
/ avg req/sec	899.12	874.25	⚠️ -24.87
/error-in-render failed reqs	0	0	✓
/error-in-render total time (seconds)	1.583	1.527	-0.06
/error-in-render avg req/sec	1579.49	1637.47	+57.98

Client Bundles (main, webpack, commons)

	vercel/next.js canary	timneutkens/next.js add/json-traces	Change
745.HASH.js gzip	179 B	179 B	✓
framework-HASH.js gzip	42.2 kB	42.2 kB	✓
main-HASH.js gzip	23.3 kB	23.3 kB	✓
webpack-HASH.js gzip	1.45 kB	1.45 kB	✓
Overall change	67.2 kB	67.2 kB	✓

Legacy Client Bundles (polyfills)

	vercel/next.js canary	timneutkens/next.js add/json-traces	Change
polyfills-a4..dd70.js gzip	31 kB	31 kB	✓
Overall change	31 kB	31 kB	✓

Client Pages

	vercel/next.js canary	timneutkens/next.js add/json-traces	Change
_app-HASH.js gzip	979 B	979 B	✓
_error-HASH.js gzip	194 B	194 B	✓
amp-HASH.js gzip	312 B	312 B	✓
css-HASH.js gzip	329 B	329 B	✓
dynamic-HASH.js gzip	2.67 kB	2.67 kB	✓
head-HASH.js gzip	351 B	351 B	✓
hooks-HASH.js gzip	918 B	918 B	✓
image-HASH.js gzip	4.14 kB	4.14 kB	✓
index-HASH.js gzip	261 B	261 B	✓
link-HASH.js gzip	1.66 kB	1.66 kB	✓
routerDirect..HASH.js gzip	318 B	318 B	✓
script-HASH.js gzip	387 B	387 B	✓
withRouter-HASH.js gzip	320 B	320 B	✓
bb14e60e810b..30f.css gzip	125 B	125 B	✓
Overall change	13 kB	13 kB	✓

Client Build Manifests

	vercel/next.js canary	timneutkens/next.js add/json-traces	Change
_buildManifest.js gzip	491 B	491 B	✓
Overall change	491 B	491 B	✓

Rendered Page Sizes

	vercel/next.js canary	timneutkens/next.js add/json-traces	Change
index.html gzip	540 B	540 B	✓
link.html gzip	552 B	552 B	✓
withRouter.html gzip	534 B	534 B	✓
Overall change	1.63 kB	1.63 kB	✓

---

Webpack 4 Mode

General Overall increase ⚠️

	vercel/next.js canary	timneutkens/next.js add/json-traces	Change
buildDuration	12.8s	13.4s	⚠️ +619ms
buildDurationCached	5.5s	5.3s	-215ms
nodeModulesSize	61.7 MB	61.7 MB	⚠️ +7.33 kB

Page Load Tests Overall increase ✓

	vercel/next.js canary	timneutkens/next.js add/json-traces	Change
/ failed reqs	0	0	✓
/ total time (seconds)	2.781	2.794	⚠️ +0.01
/ avg req/sec	898.92	894.74	⚠️ -4.18
/error-in-render failed reqs	0	0	✓
/error-in-render total time (seconds)	1.551	1.546	0
/error-in-render avg req/sec	1612.01	1617.07	+5.06

Client Bundles (main, webpack, commons)

	vercel/next.js canary	timneutkens/next.js add/json-traces	Change
16.HASH.js gzip	186 B	186 B	✓
677f882d2ed8..HASH.js gzip	14.1 kB	14.1 kB	✓
framework.HASH.js gzip	41.9 kB	41.9 kB	✓
main-HASH.js gzip	10.7 kB	10.7 kB	✓
webpack-HASH.js gzip	1.19 kB	1.19 kB	✓
Overall change	68.1 kB	68.1 kB	✓

Legacy Client Bundles (polyfills)

	vercel/next.js canary	timneutkens/next.js add/json-traces	Change
polyfills-a4..dd70.js gzip	31 kB	31 kB	✓
Overall change	31 kB	31 kB	✓

Client Pages

	vercel/next.js canary	timneutkens/next.js add/json-traces	Change
_app-HASH.js gzip	964 B	964 B	✓
_error-HASH.js gzip	3.8 kB	3.8 kB	✓
amp-HASH.js gzip	552 B	552 B	✓
css-HASH.js gzip	333 B	333 B	✓
dynamic-HASH.js gzip	2.87 kB	2.87 kB	✓
head-HASH.js gzip	3.06 kB	3.06 kB	✓
hooks-HASH.js gzip	924 B	924 B	✓
index-HASH.js gzip	231 B	231 B	✓
link-HASH.js gzip	1.64 kB	1.64 kB	✓
routerDirect..HASH.js gzip	298 B	298 B	✓
script-HASH.js gzip	3.03 kB	3.03 kB	✓
withRouter-HASH.js gzip	295 B	295 B	✓
30809af5c834..565.css gzip	125 B	125 B	✓
Overall change	18.1 kB	18.1 kB	✓

Client Build Manifests

	vercel/next.js canary	timneutkens/next.js add/json-traces	Change
_buildManifest.js gzip	500 B	500 B	✓
Overall change	500 B	500 B	✓

Rendered Page Sizes

	vercel/next.js canary	timneutkens/next.js add/json-traces	Change
index.html gzip	585 B	585 B	✓
link.html gzip	597 B	597 B	✓
withRouter.html gzip	579 B	579 B	✓
Overall change	1.76 kB	1.76 kB	✓

Commit: fdd5d1a

[ijjk]

Failing test suites

Commit: fdd5d1a

test/integration/route-load-cancel/test/index.test.js

• next/dynamic > dev mode > should cancel slow page loads on re-navigation

Expand output

● next/dynamic › dev mode › should cancel slow page loads on re-navigation

NoSuchElementError: no such element: Unable to locate element: {"method":"css selector","selector":"#page-text"}
  (Session info: headless chrome=92.0.4515.131)

  21 | const appDir = join(__dirname, '../')
  22 |
> 23 | function runTests() {
     |                      ^
  24 |   it('should cancel slow page loads on re-navigation', async () => {
  25 |     const browser = await webdriver(appPort, '/')
  26 |     await waitFor(5000)

  at Object.throwDecodedError (../node_modules/selenium-webdriver/lib/error.js:550:15)
  at parseHttpResponse (../node_modules/selenium-webdriver/lib/http.js:565:13)
  at Executor.execute (../node_modules/selenium-webdriver/lib/http.js:491:26)
  at thenableWebDriverProxy.execute (../node_modules/selenium-webdriver/lib/webdriver.js:700:17)
  at Object.<anonymous> (integration/route-load-cancel/test/index.test.js:23:22)