feat: implement static file serving to fix 404 errors for client assets

- Add isStaticAsset() function to identify static files and assets
- Implement tryServeStaticFile() with proper content type detection
- Serve static files directly from Lambda filesystem before SvelteKit processing
- Handle prerendered routes by letting SvelteKit process them
- Add comprehensive file extension support and caching headers
- Fix import organization and formatting per linting rules

This resolves the production issue where Lambda returned 404 for client JS files.

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <[email protected]>

Author: oladayo21

.claude/settings.local.json

@@ -9,7 +9,12 @@
       "Bash(pnpm:*)",
       "Bash(git remote add:*)",
       "Bash(git init:*)",
-      "Bash(git add:*)"
+      "Bash(git add:*)",
+      "Bash(git commit:*)",
+      "Bash(git push:*)",
+      "Bash(git pull:*)",
+      "Bash(ls:*)",
+      "Bash(find:*)"
     ],
     "deny": []
   }

CLAUDE.md

@@ -90,4 +90,8 @@ Templates use placeholder replacement (ENV, HANDLER, MANIFEST, etc.) during buil
 - Add comments only where necessary to help understand complex logic
 - No comments for comments' sake - avoid obvious or redundant explanations
 - Focus on explaining "why" rather than "what" for non-obvious implementation details
-- Document SvelteKit integration points and Lambda-specific optimizations
+- Document SvelteKit integration points and Lambda-specific optimizations
+
+## Development Principles
+
+- Always run all necessary checks after you create code to make sure everything works as they should

files/handler.js

@@ -1,7 +1,10 @@
 import 'SHIMS';
 import { env } from 'ENV';
-import { manifest, prerendered, base } from 'MANIFEST';
+import { manifest, prerendered } from 'MANIFEST';
 import { Server } from 'SERVER';
+import { readFileSync } from 'node:fs';
+import { dirname, extname, join } from 'node:path';
+import { fileURLToPath } from 'node:url';
 // 🔥 Use our robust converters instead of basic event parsing
 import {
   convertLambdaEventToWebRequest,
@@ -16,6 +19,9 @@ const server = new Server(manifest);
 const body_size_limit = Number.parseInt(env('BODY_SIZE_LIMIT', 'BODY_SIZE_LIMIT'));
 const binaryMediaTypes = BINARY_MEDIA_TYPES;
 
+// Get the directory of this handler file
+const __dirname = dirname(fileURLToPath(import.meta.url));
+
 await server.init({
   env: process.env,
 });
@@ -89,19 +95,65 @@ function isALBEvent(event) {
  * @returns {boolean}
  */
 function isStaticAsset(pathname) {
-    return pathname.startsWith(`${base}/_app/`) || 
-           pathname.startsWith(`${base}/favicon.`) ||
-           pathname.endsWith('.css') ||
-           pathname.endsWith('.js') ||
-           pathname.endsWith('.woff') ||
-           pathname.endsWith('.woff2') ||
-           pathname.endsWith('.png') ||
-           pathname.endsWith('.jpg') ||
-           pathname.endsWith('.jpeg') ||
-           pathname.endsWith('.gif') ||
-           pathname.endsWith('.svg') ||
-           pathname.endsWith('.webp') ||
-           pathname.endsWith('.ico');
+  return (
+    pathname.startsWith('/_app/') ||
+    pathname.startsWith('/favicon.') ||
+    pathname.endsWith('.css') ||
+    pathname.endsWith('.js') ||
+    pathname.endsWith('.woff') ||
+    pathname.endsWith('.woff2') ||
+    pathname.endsWith('.png') ||
+    pathname.endsWith('.jpg') ||
+    pathname.endsWith('.jpeg') ||
+    pathname.endsWith('.gif') ||
+    pathname.endsWith('.svg') ||
+    pathname.endsWith('.webp') ||
+    pathname.endsWith('.ico')
+  );
+}
+
+/**
+ * Serve static files from the bundled client directory
+ * @param {string} pathname - The requested pathname
+ * @returns {Promise<Response|null>} - Response for static file or null if not found
+ */
+async function tryServeStaticFile(pathname) {
+  try {
+    const fullPath = join(__dirname, 'client', pathname);
+    const content = readFileSync(fullPath);
+
+    // Determine content type
+    const ext = extname(pathname).toLowerCase();
+    const contentType =
+      {
+        '.js': 'application/javascript',
+        '.css': 'text/css',
+        '.ico': 'image/x-icon',
+        '.png': 'image/png',
+        '.jpg': 'image/jpeg',
+        '.jpeg': 'image/jpeg',
+        '.gif': 'image/gif',
+        '.svg': 'image/svg+xml',
+        '.webp': 'image/webp',
+        '.woff': 'font/woff',
+        '.woff2': 'font/woff2',
+        '.ttf': 'font/ttf',
+        '.eot': 'application/vnd.ms-fontobject',
+      }[ext] || 'application/octet-stream';
+
+    return new Response(content, {
+      status: 200,
+      headers: {
+        'Content-Type': contentType,
+        'Cache-Control': pathname.includes('/immutable/')
+          ? 'public, max-age=31536000, immutable'
+          : 'public, max-age=3600',
+      },
+    });
+  } catch {
+    // File not found or error reading
+    return null;
+  }
 }
 
 /**
@@ -115,17 +167,20 @@ export const handler = async (event, context) => {
     // 🔥 Use our superior event conversion (handles all Lambda event types)
     const webRequest = convertLambdaEventToWebRequest(event);
     const pathname = new URL(webRequest.url).pathname;
-    
-    // Check for prerendered routes
-    if (prerendered.has(pathname)) {
-        // Let SvelteKit handle prerendered routes
-        // Fall through to normal processing
-    }
 
-    // Static assets - let SvelteKit handle them
-    if (isStaticAsset(pathname)) {
-        // Let SvelteKit handle static assets
-        // Fall through to normal processing
+    // Check for prerendered routes - let SvelteKit handle them
+    if (prerendered.has(pathname)) {
+      // Fall through to normal SvelteKit processing
+    } else if (isStaticAsset(pathname)) {
+      // Try to serve static files directly
+      const staticFileResponse = await tryServeStaticFile(pathname);
+      if (staticFileResponse) {
+        return await convertWebResponseToLambdaEvent(staticFileResponse, {
+          binaryMediaTypes,
+          multiValueHeaders: isALBEvent(event),
+        });
+      }
+      // If static file not found, fall through to SvelteKit
     }
 
     // Convert to Node.js request format for SvelteKit