Production nextjs server builds should not include playwright dependency by default!

[cefn]

Update: Between 15.3.2 and 15.3.4 the swc binary download hack was substantially changed making some of the commentary below incorrect now. I am closing in favour of a new ticket.

Goals

1. It should be possible to run the equivalent of next start without including unnecessary dependencies especially test-only modules like playwright (and probably without build-time modules like swc)

Non-Goals

There is nothing wrong with playwright or swc as dev deps, but these need to be separable for production containers!

Background

Currently if you install a project like...

pnpm install --prod

It brings with it a whole host of dependencies which are incorrect for production deployment. An example is the babel react compiler and the playwright test framework, as you can see here...

next.js/packages/next/package.json

Lines 118 to 129 in 09a2167

	"babel-plugin-react-compiler": {
	"optional": true
	},
	"sass": {
	"optional": true
	},
	"@opentelemetry/api": {
	"optional": true
	},
	"@playwright/test": {
	"optional": true
	}

Although this already seems like a misuse of optional to be stricter with the install you can run...

pnpm install --prod --no-optional

However, if you pursue this line (e.g. trying to build a docker environment with only non-optional prod dependencies, plus a built .next folder) you will find that npm exec next start fails given its resolution of swc depends on optional dependencies being installed, meaning it's not possible to separate these non-production dependencies at all...

Downloading swc package @next/swc-linux-x64-gnu... to /root/.cache/next-swc
error This project's package.json defines "packageManager": "yarn@[email protected]". However the current global version of Yarn is 1.22.22.

That's because SWC is resolved as an optional dependency (presumably because it's multi-platform Rust). So therefore if you try to install and run next without optional dependencies next can't run at all. It attempts to patch itself dynamically, which is a bad idea in a server infrastructure, and also fails at that.

I spent an age trying to work out what was wrong with our build pipelines that was bringing in the whole of Playwright, and then I found astonishingly it was deliberate and part of NextJS. However, trying to REMOVE playwright proves to be impossible thanks to the uncleanliness of optional dependencies in Next.

Proposal

• Preferably Next would not need to be installed with optional dependencies, (because then they stop being optional!). Test it without optional dependencies, and check it still works.
• Next best thing, don't try to load SWC at runtime which should have already finished its job at build time!
• If runtime resolution of SWC is somehow needed to get SWC to be usable in Next, and the only mechanism for this is via optional dependencies then be cleaner about what ELSE is optional, and don't include the whole of playwright, therefore requiring projects to install playwright in their docker containers to run next!

[cefn]

For those curious about a workaround, in our production containers without optional dependencies we need to selectively pick from a platform specific module, and install it like pnpm add --prod --no-optional @next/[email protected] which then makes it possible to launch next. This has to be hacked in specifically for the platform and can't be a general dependency (since then the dev mode won't work on our developers macs as well as being possible to run in container).

[cefn]

Looks like a minor has adopted a new way to resolve swc binaries ( changed radically between 15.3.2 and 15.3.4 ).

Nevertheless, the fact that next installs playwright by default when you run pnpm install --prod is weird and problematic.

[cefn]

Closing in favour of a new ticket since SWC downloader has changed in last minor version.

[ricardasjak]

Why would you have Playwright dependency in fresh Nextjs project to begin with?