Add process env NEXT_RUNTIME

[huozhi]

• To help determine the current running environment is in server nodejs / edge runtime
• Remove usage of process.browser

[ijjk]

Failing test suites

Commit: 138d4e2

yarn testheadless test/production/middleware-environment-variables-in-node-server-reflect-the-usage-inference/index.test.ts

• middleware environment variables in node server reflect the usage inference > limits process.env to only contain env vars that are inferred from usage

Expand output

● middleware environment variables in node server reflect the usage inference › limits process.env to only contain env vars that are inferred from usage

expect(received).toEqual(expected) // deep equality

- Expected  - 0
+ Received  + 1

  Object {
    "canBeInferred": "can-be-inferred",
    "rest": Object {
      "CAN_BE_INFERRED": "can-be-inferred",
      "X_CUSTOM_HEADER": "x-custom-header",
+     "__NEXT_RUNTIME": "edge",
    },
  }

  40 |       parsed = JSON.parse(html)
  41 |     }).not.toThrow()
> 42 |     expect(parsed).toEqual({
     |                    ^
  43 |       canBeInferred: 'can-be-inferred',
  44 |       rest: {
  45 |         CAN_BE_INFERRED: 'can-be-inferred',

  at Object.<anonymous> (production/middleware-environment-variables-in-node-server-reflect-the-usage-inference/index.test.ts:42:20)

Read more about building and testing Next.js in contributing.md.

[ijjk]

Stats from current PR

Default Build (Decrease detected ✓)

General Overall increase ⚠️

	vercel/next.js canary	huozhi/next.js process-edge	Change
buildDuration	18.8s	18.7s	-126ms
buildDurationCached	7.3s	7.3s	-14ms
nodeModulesSize	481 MB	481 MB	⚠️ +1.64 kB

Page Load Tests Overall decrease ⚠️

	vercel/next.js canary	huozhi/next.js process-edge	Change
/ failed reqs	0	0	✓
/ total time (seconds)	3.832	3.828	0
/ avg req/sec	652.39	653.01	+0.62
/error-in-render failed reqs	0	0	✓
/error-in-render total time (seconds)	1.606	1.609	0
/error-in-render avg req/sec	1556.41	1554.12	⚠️ -2.29

Client Bundles (main, webpack)

	vercel/next.js canary	huozhi/next.js process-edge	Change
925.HASH.js gzip	179 B	179 B	✓
framework-HASH.js gzip	42 kB	42 kB	✓
main-HASH.js gzip	28.6 kB	28.6 kB	✓
webpack-HASH.js gzip	1.44 kB	1.44 kB	✓
Overall change	72.3 kB	72.3 kB	✓

Legacy Client Bundles (polyfills)

	vercel/next.js canary	huozhi/next.js process-edge	Change
polyfills-HASH.js gzip	31 kB	31 kB	✓
Overall change	31 kB	31 kB	✓

Client Pages

	vercel/next.js canary	huozhi/next.js process-edge	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	3.08 kB	3.08 kB	✓
head-HASH.js gzip	357 B	357 B	✓
hooks-HASH.js gzip	920 B	920 B	✓
image-HASH.js gzip	5.73 kB	5.73 kB	✓
index-HASH.js gzip	263 B	263 B	✓
link-HASH.js gzip	2.63 kB	2.63 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	16.3 kB	16.3 kB	✓

Client Build Manifests

	vercel/next.js canary	huozhi/next.js process-edge	Change
_buildManifest.js gzip	459 B	459 B	✓
Overall change	459 B	459 B	✓

Rendered Page Sizes

	vercel/next.js canary	huozhi/next.js process-edge	Change
index.html gzip	532 B	532 B	✓
link.html gzip	545 B	545 B	✓
withRouter.html gzip	525 B	525 B	✓
Overall change	1.6 kB	1.6 kB	✓

---

Default Build with SWC

General Overall increase ⚠️

	vercel/next.js canary	huozhi/next.js process-edge	Change
buildDuration	20.9s	20.8s	-27ms
buildDurationCached	7.3s	7.2s	-69ms
nodeModulesSize	481 MB	481 MB	⚠️ +1.64 kB

Page Load Tests Overall increase ✓

	vercel/next.js canary	huozhi/next.js process-edge	Change
/ failed reqs	0	0	✓
/ total time (seconds)	3.877	3.833	-0.04
/ avg req/sec	644.85	652.26	+7.41
/error-in-render failed reqs	0	0	✓
/error-in-render total time (seconds)	1.63	1.633	0
/error-in-render avg req/sec	1533.56	1531.16	⚠️ -2.4

Client Bundles (main, webpack)

	vercel/next.js canary	huozhi/next.js process-edge	Change
925.HASH.js gzip	178 B	178 B	✓
framework-HASH.js gzip	42.2 kB	42.2 kB	✓
main-HASH.js gzip	29.1 kB	29.1 kB	✓
webpack-HASH.js gzip	1.45 kB	1.45 kB	✓
Overall change	72.9 kB	72.9 kB	✓

Legacy Client Bundles (polyfills)

	vercel/next.js canary	huozhi/next.js process-edge	Change
polyfills-HASH.js gzip	31 kB	31 kB	✓
Overall change	31 kB	31 kB	✓

Client Pages

	vercel/next.js canary	huozhi/next.js process-edge	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	3.08 kB	3.08 kB	✓
head-HASH.js gzip	359 B	359 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	2.74 kB	2.74 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	16.5 kB	16.5 kB	✓

Client Build Manifests

	vercel/next.js canary	huozhi/next.js process-edge	Change
_buildManifest.js gzip	458 B	458 B	✓
Overall change	458 B	458 B	✓

Rendered Page Sizes

	vercel/next.js canary	huozhi/next.js process-edge	Change
index.html gzip	529 B	529 B	✓
link.html gzip	541 B	541 B	✓
withRouter.html gzip	525 B	525 B	✓
Overall change	1.59 kB	1.59 kB	✓

Commit: 79a26ef

[ijjk]

Do we need to always expose this or can we only expose it if it's referenced like other environment variables in the edge runtime?

[huozhi]

It's used inside the next server code to determine wether we use node or polyfill dependencies, so it's required at the very beginning that can't remove atm. I'll keep it in mind to see if we can opt it in the later versions