12.0.9-canary.11 5x'd size of edge SSR bundle

[leo]

Run next info (available from version 12.0.8 and up)

Operating System:
  Platform: darwin
  Arch: arm64
  Version: Darwin Kernel Version 21.2.0: Sun Nov 28 20:29:10 PST 2021; root:xnu-8019.61.5~1/RELEASE_ARM64_T8101
Binaries:
  Node: 16.14.0
  npm: 8.3.1
  Yarn: 1.22.17
  pnpm: 6.30.1
Relevant packages:
  next: 12.0.9-canary.11
  react: 18.0.0-rc.0-next-fe905f152-20220107
  react-dom: 18.0.0-rc.0-next-fe905f152-20220107

What version of Next.js are you using?

12.0.9-canary.11

What version of Node.js are you using?

16.14.0

What browser are you using?

Chrome (latest)

What operating system are you using?

macOS (latest)

How are you deploying your application?

Vercel

Describe the Bug

• Version 12.0.9-canary.9 of Next.js comes with fairly small edge SSR bundles (∼ a few hundred KB in total).
• Version 12.0.9-canary.10 doesn't exist on npm (FYI, just to clarify that there's no version in between).
• Version 12.0.9-canary.11 made their size shoot up to over 1,3 MB (∼ x5) for just a single chunk.

Initially, I assumed this would be a problem in my own application, but after hours of investigation, I got to understand that version 12.0.9-canary.9 of Next.js didn't have this problem, and that 12.0.9-canary.11 had introduced it.

It was probably caused by #33635, is my guess.

Analysis of version 12.0.9-canary.11

Analysis of version 12.0.9-canary.9

Expected Behavior

It seems unintentional that the size of individual edge SSR bundles was increased by 5x, just to support the expected functionality when rendering.

It'd be great if they'd return to a size that's closer to their original one, since a larger bundle effects the server-rendering performance (that's part of the reason why Cloudflare Workers [and probably others too] limit them to 1 MB by default, which is now being exceeded as of 12.0.9-canary.11).

Also note that next-rsc-demo worked just fine before 12.0.9-canary.11. I understand that new functionality was added, but the penalty for that seems to be way too large.

To Reproduce

1. Clone Vercel's next-rsc-demo
2. Upgrade the next dependency to 12.0.9-canary.9
3. Notice that the bundle files in .next/server/chunks have a "reasonable" size
4. Upgrade the next dependency to 12.0.9-canary.11
5. Notice that the bundle files in .next/server/chunks have suddenly shot up to over 1 MB for one chunk

[icyJoseph]

Hi,

I do see that a chunk shoots up to 1.3MiB on 12.0.9-canary.11.

    1.3 MiB [##########]  817.js
   28.0 KiB [          ]  40.js
    8.0 KiB [          ]  863.js
    4.0 KiB [          ]  976.js
    4.0 KiB [          ]  144.js
    4.0 KiB [          ]  font-manifest.json

Is there any limitation for you to try 12.0.11-canary.11? I have tried with that build, and the error is gone.

   76.0 KiB [##########]  664.js
   16.0 KiB [##        ]  755.js
    4.0 KiB [          ]  320.js
    4.0 KiB [          ]  730.js
    4.0 KiB [          ]  font-manifest.json

My wild guess is that the import in packages/next/server/web-server.ts, was bringing unwanted modules.

import { LoadComponentsReturnType } from './load-components'

The current implementation is doing the proper way to bring a type, without bringing the entire module:

import type { LoadComponentsReturnType } from './load-components'

[leo]

@icyJoseph Have you changed anything else when switching to 12.0.11-canary.11?

For me, anything above 12.0.9-canary.11 (and therefore also 12.0.11-canary.11) has this problem.

[leo]

To verify what I said above, run npm install and ANALYZE="1" npm run build in this repo.

This is the result I got:

[icyJoseph]

Aha, now I got it. Confirmed. Somewhere, there's a Buffer being used! I think that explains crypto-browserify's present, and probably raw-body. I guess it could also be that for some reason, the bundler is assuming that it needs to pack browserified versions of Node API's, instead of letting them raw.

Sorry for the initial misfire. It seems I had messed up the runtime value.

I'll keep looking around.

[shuding]

Hi all, thanks for reporting & looking into this! We are aware of the size increase, and we are work on optimizing the base server. Will keep this issue open for tracking. 🙏

[leo]

@shuding I think this issue can be closed now, correct?