add support for importing css files in fixture

fixtures/flight-vite/scripts/build.js

@@ -168,6 +168,11 @@ async function build() {
       external: ['react', 'react-dom', 'react-server-dom-vite'],
     },
   });
+
+  // copy assets from react-server build to static build, this includes stylesheets improted from server components
+  await fs.promises.cp('build/react-server/assets', 'build/static/assets', {
+    recursive: true,
+  });
 }
 
 build();

fixtures/flight-vite/server/manifest.js

@@ -0,0 +1,52 @@
+'use strict';
+
+/**
+ * Traverses the module graph and collects assets for a given chunk
+ *
+ * @param manifest Client manifest
+ * @param id Chunk id
+ * @param assetMap Cache of assets
+ * @returns Array of asset URLs
+ */
+const findAssetsInManifest = (manifest, id, assetMap = new Map()) => {
+  function traverse(id) {
+    const cached = assetMap.get(id);
+    if (cached) {
+      return cached;
+    }
+    const chunk = manifest[id];
+    if (!chunk) {
+      return [];
+    }
+    const assets = [
+      ...(chunk.assets || []),
+      ...(chunk.css || []),
+      ...(chunk.imports?.flatMap(traverse) || []),
+    ];
+    const imports = chunk.imports?.flatMap(traverse) || [];
+    const all = [...assets, ...imports].filter(Boolean);
+    all.push(chunk.file);
+    assetMap.set(id, all);
+    return Array.from(new Set(all));
+  }
+  return traverse(id);
+};
+
+const findAssetsInModuleNode = moduleNode => {
+  const seen = new Set();
+  function traverse(node) {
+    if (seen.has(node.url)) {
+      return [];
+    }
+    seen.add(node.url);
+
+    const imports = [...node.importedModules].flatMap(traverse) || [];
+    imports.push(node.url);
+    return Array.from(new Set(imports));
+  }
+  return traverse(moduleNode);
+};
+
+module.exports = {
+  findAssetsInManifest,
+};

fixtures/flight-vite/server/region.js

@@ -64,6 +64,11 @@ async function createApp() {
       return viteServer.ssrLoadModule(id);
     };
 
+    const {collectStyles} = require('./styles.js');
+    globalThis.__vite_find_assets__ = async entries => {
+      return Object.keys(await collectStyles(viteServer, entries));
+    };
+
     loadModule = async entry => {
       return await viteServer.ssrLoadModule(
         path.isAbsolute(entry)
@@ -92,10 +97,18 @@ async function createApp() {
 
     globalThis.__vite_module_cache__ = new Map();
     globalThis.__vite_require__ = id => {
+      console.log({id});
       return import(
         path.join(process.cwd(), 'build', 'react-server', id + '.js')
       );
     };
+    const {findAssetsInManifest} = require('./manifest.js');
+
+    globalThis.__vite_find_assets__ = async entries => {
+      return findAssetsInManifest(reactServerManifest, entries[0]).filter(
+        asset => asset.endsWith('.css')
+      );
+    };
   }
 
   async function renderApp(res, returnValue) {

fixtures/flight-vite/server/styles.js

@@ -0,0 +1,103 @@
+'use strict';
+
+const path = require('node:path');
+
+async function findDeps(vite, node, deps) {
+  // since `ssrTransformResult.deps` contains URLs instead of `ModuleNode`s, this process is asynchronous.
+  // instead of using `await`, we resolve all branches in parallel.
+  const branches = [];
+
+  async function add(node) {
+    if (!deps.has(node)) {
+      deps.add(node);
+      await findDeps(vite, node, deps);
+    }
+  }
+
+  async function add_by_url(url) {
+    const node = await vite.moduleGraph.getModuleByUrl(url);
+
+    if (node) {
+      await add(node);
+    }
+  }
+
+  if (node.ssrTransformResult) {
+    if (node.ssrTransformResult.deps) {
+      node.ssrTransformResult.deps.forEach(url =>
+        branches.push(add_by_url(url))
+      );
+    }
+
+    // if (node.ssrTransformResult.dynamicDeps) {
+    //   node.ssrTransformResult.dynamicDeps.forEach(url => branches.push(add_by_url(url)));
+    // }
+  } else {
+    node.importedModules.forEach(node => branches.push(add(node)));
+  }
+
+  await Promise.all(branches);
+}
+
+// Vite doesn't expose this so we just copy the list for now
+// https://github.com/vitejs/vite/blob/3edd1af56e980aef56641a5a51cf2932bb580d41/packages/vite/src/node/plugins/css.ts#L96
+const STYLE_ASSET_REGEX = /\.(css|less|sass|scss|styl|stylus|pcss|postcss)$/;
+const MODULE_STYLE_ASSET_REGEX =
+  /\.module\.(css|less|sass|scss|styl|stylus|pcss|postcss)$/;
+
+async function collectStyles(devServer, match) {
+  const styles = {};
+  const deps = new Set();
+  try {
+    for (const file of match) {
+      const resolvedId = await devServer.pluginContainer.resolveId(file);
+
+      if (!resolvedId) {
+        console.log('not found');
+        continue;
+      }
+
+      const id = resolvedId.id;
+
+      const normalizedPath = path.resolve(id).replace(/\\/g, '/');
+      let node = devServer.moduleGraph.getModuleById(normalizedPath);
+      if (!node) {
+        const absolutePath = path.resolve(file);
+        await devServer.ssrLoadModule(absolutePath);
+        node = await devServer.moduleGraph.getModuleByUrl(absolutePath);
+
+        if (!node) {
+          console.log('not found');
+          return;
+        }
+      }
+
+      await findDeps(devServer, node, deps);
+    }
+  } catch (e) {
+    console.error(e);
+  }
+
+  for (const dep of deps) {
+    const parsed = new URL(dep.url, 'http://localhost/');
+    const query = parsed.searchParams;
+
+    if (STYLE_ASSET_REGEX.test(dep.file ?? '')) {
+      try {
+        const mod = await devServer.ssrLoadModule(dep.url);
+        // if (module_STYLE_ASSET_REGEX.test(dep.file)) {
+        // 	styles[dep.url] = env.cssModules?.[dep.file];
+        // } else {
+        styles[dep.url] = mod.default;
+        // }
+      } catch {
+        // this can happen with dynamically imported modules, I think
+        // because the Vite module graph doesn't distinguish between
+        // static and dynamic imports? TODO investigate, submit fix
+      }
+    }
+  }
+  return styles;
+}
+
+module.exports = {collectStyles};

fixtures/flight-vite/src/App.jsx

@@ -14,6 +14,17 @@ const REACT_REFRESH_PREAMBLE = `
   window.__vite_plugin_react_preamble_installed__ = true
 `;
 
+async function Assets() {
+  const styles = await __vite_find_assets__(['src/App.jsx']);
+  return (
+    <>
+      {styles.map(key => (
+        <link key={key} rel="stylesheet" href={key} />
+      ))}
+    </>
+  );
+}
+
 export default async function App() {
   const res = await fetch('http://localhost:3001/todos');
   const todos = await res.json();
@@ -23,7 +34,6 @@ export default async function App() {
         <meta charSet="utf-8" />
         <meta name="viewport" content="width=device-width, initial-scale=1" />
         <title>Flight</title>
-        <link rel="stylesheet" href="/src/style.css" />
         {import.meta.env.DEV ? (
           <>
             <script type="module" src="@vite/client" />
@@ -35,6 +45,7 @@ export default async function App() {
             />
           </>
         ) : null}
+        <Assets />
       </head>
       <body>
         <div>