rwsdk/dist/vite/cloudflarePreInitPlugin.mjs

Build fast, server-driven webapps on Cloudflare with SSR, RSC, and realtime

/**
 * Plugin that performs initialization workarounds that must run before
 * the Cloudflare plugin's `configureServer` hook executes.
 *
 * Cloudflare plugin v1.15.0 executes the worker entry file during
 * `configureServer` to detect exports, which triggers SSR code evaluation
 * before normal server initialization completes. This plugin ensures
 * required systems are initialized beforehand.
 */
export const cloudflarePreInitPlugin = () => {
    return {
        name: "rwsdk:cloudflare-pre-init",
        // context(justinvdm, 20 Jan 2025): This plugin must run before the
        // Cloudflare plugin's `configureServer` hook. The Cloudflare plugin
        // executes the worker entry file during `configureServer` to detect
        // exports, and blocks the rest of the configureServer plugins until the
        // request is complete. We must initialize required systems (SSR dependency
        // optimizer + our own plugins to them, as well as CSS plugin's moduleCache)
        // before this happens to prevent errors.
        enforce: "pre",
        async configureServer(server) {
            // context(justinvdm, 20 Jan 2025): Initialize SSR dependency optimizer before
            // Cloudflare plugin triggers SSR code evaluation. This ensures dependencies
            // in `optimizeDeps.include` (like `react-dom/server.edge`) are correctly
            // registered before they are discovered lazily.
            if (server.environments.ssr?.depsOptimizer) {
                await server.environments.ssr.depsOptimizer.init();
            }
            // context(justinvdm, 20 Jan 2025): Initialize CSS plugin's shared moduleCache
            // before CSS modules are processed. The Cloudflare plugin's export detection
            // can trigger CSS module processing in the SSR environment during `configureServer`,
            // which happens before `initServer` runs. Vite's CSS plugin uses a shared
            // `moduleCache` that is initialized in the client environment's `buildStart` hook.
            // By calling `buildStart` here (which is idempotent), we ensure the CSS plugin's
            // cache is initialized before CSS modules are processed, preventing "Cannot read
            // properties of undefined (reading 'set')" errors.
            await server.environments.client.pluginContainer.buildStart();
        },
    };
};