Allow Vite plugin to build server first, client last

[bndkt]

Describe the solution

I'm currently building a RSC framework/Vite plugin which I want to use in combination with the Cloudflare Vite plugin. For the RSC plugin to work, it is important that the server/ssr bundle is built first, and the client bundle is built last (because client components get discovered during SSR build and then included in the client build).

The Cloudflare Vite plugin currently takes over the build process via builder.buildApp, yielding to a user config in case there is one (see

workers-sdk/packages/vite-plugin-cloudflare/src/index.ts

Line 142 in d9d937a

userConfig.builder?.buildApp ??

). I can provide my own builder.buildApp hook to make sure the build happens in the desired order, so this part works.

The one thing that doesn't work is that the assets config in the generated wrangler.json is only added if "hasClientBuild" is set (see

workers-sdk/packages/vite-plugin-cloudflare/src/index.ts

Line 224 in d9d937a

if (isEntryWorker && hasClientBuild) {

), which is only set when there was a previous build for the "client" environment.

Do you think it would be possible to change the hasClientBuild check towards something that checks if there is a client environment configured and doesn't rely on the client environment being built previously? I'm happy to create a PR for this if you'd be open to changing this.

Maybe it would even make sense to offer a "buildClientLast" option for the plugin, so that this could be set in the Cloudflare Vite plugin config? Then I wouldn't even need to take over the build process myself.

[bndkt]

For reference, hasClientBuild is set here:

workers-sdk/packages/vite-plugin-cloudflare/src/index.ts

Lines 297 to 301 in d9d937a

	// This relies on the assumption that the client environment is built first
	// Composable `buildApp` hooks could provide a more robust alternative in future
	if (this.environment.name === "client") {
	hasClientBuild = true;
	}

And I just noticed the fact that it relies on the client build being done first is even acknowledged in a comment here.

[jamesopstad]

Great that you're exploring this! As you spotted from the comment, the way we do this at the moment isn't ideal. Vite is introducing a new buildApp hook, based on our feedback, so I think we'll be able to approach this in a more flexible way soon. This will be released in Vite 7, which is imminent, and makes it possible to know which environments have already been built. We need to have a think about exactly how to incorporate this and will bear your use case in mind.

For now, you could potentially modify the output wrangler.json file that has been written in your buildApp once both environments have been built. Not ideal, but a temporary solution at least until we have something better.