SSR Output includes files which are only relevant for prerendering

[alexanderniebuhr]

The SSR output of astro build, which is located in dist/_worker.js directory, contains files which are not used in SSR and only used for prerendering locally. We should not keep them and upload them to Cloudflare.

The goal is:

• not to add a second bundling step
• keep the SSR file chunks the same they are after running astro build
• making sure unused files & chunks (because they are only needed for prerendering) are removed
• if necessary put this under an experimental flag for the adapters options

Potential important parts of the code:

adapters/packages/cloudflare/src/index.ts

Lines 81 to 88 in b153fc4

	vite: {
	// load .wasm files as WebAssembly modules
	plugins: [
	wasmModuleLoader({
	disabled: !args?.wasmModuleImports,
	}),
	],
	},

adapters/packages/cloudflare/src/index.ts

Lines 145 to 213 in b153fc4

	'astro:build:setup': ({ vite, target }) => {
	if (target === 'server') {
	vite.resolve ||= {};
	vite.resolve.alias ||= {};
	const aliases = [
	{
	find: 'react-dom/server',
	replacement: 'react-dom/server.browser',
	},
	];
	if (Array.isArray(vite.resolve.alias)) {
	vite.resolve.alias = [...vite.resolve.alias, ...aliases];
	} else {
	for (const alias of aliases) {
	(vite.resolve.alias as Record<string, string>)[alias.find] = alias.replacement;
	}
	}
	vite.resolve.conditions ||= [];
	// We need those conditions, previous these conditions where applied at the esbuild step which we removed
	// https://github.com/withastro/astro/pull/7092
	vite.resolve.conditions.push('workerd', 'worker');
	vite.ssr ||= {};
	vite.ssr.target = 'webworker';
	vite.ssr.noExternal = true;
	if (typeof _config.vite.ssr?.external === 'undefined') vite.ssr.external = [];
	if (typeof _config.vite.ssr?.external === 'boolean')
	vite.ssr.external = _config.vite.ssr?.external;
	if (Array.isArray(_config.vite.ssr?.external))
	// `@astrojs/vue` sets `@vue/server-renderer` to external
	// https://github.com/withastro/astro/blob/e648c5575a8774af739231cfa9fc27a32086aa5f/packages/integrations/vue/src/index.ts#L119
	// the cloudflare adapter needs to get all dependencies inlined, we use `noExternal` for that, but any `external` config overrides that
	// therefore we need to remove `@vue/server-renderer` from the external config again
	vite.ssr.external = _config.vite.ssr?.external.filter(
	(entry) => entry !== '@vue/server-renderer'
	);
	vite.build ||= {};
	vite.build.rollupOptions ||= {};
	vite.build.rollupOptions.output ||= {};
	// @ts-expect-error
	vite.build.rollupOptions.output.banner ||=
	'globalThis.process ??= {}; globalThis.process.env ??= {};';
	vite.build.rollupOptions.external = _config.vite.build?.rollupOptions?.external ?? [];
	// Cloudflare env is only available per request. This isn't feasible for code that access env vars
	// in a global way, so we shim their access as `process.env.*`. This is not the recommended way for users to access environment variables. But we'll add this for compatibility for chosen variables. Mainly to support `@astrojs/db`
	vite.define = {
	'process.env': 'process.env',
	...vite.define,
	};
	}
	// we thought that vite config inside `if (target === 'server')` would not apply for client
	// but it seems like the same `vite` reference is used for both
	// so we need to reset the previous conflicting setting
	// in the future we should look into a more robust solution
	if (target === 'client') {
	vite.resolve ||= {};
	vite.resolve.conditions ||= [];
	vite.resolve.conditions = vite.resolve.conditions.filter(
	(c) => c !== 'workerd' && c !== 'worker'
	);
	}
	},