fix: eliminate code splitting to support Fastly runtime

Fastly's WASM runtime doesn't support importScripts which webpack uses
for code splitting. Changes:
- Convert dynamic adapter imports to static imports in edge-index.js
- Add webpackIgnore comments to fastly:* module dynamic imports
- Add splitChunks: false to webpack optimization

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

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

Signed-off-by: Lars Trieloff <[email protected]>

Author: claude

src/EdgeBundler.js

@@ -122,6 +122,8 @@ export default class EdgeBundler extends WebpackBundler {
         concatenateModules: false,
         mangleExports: false,
         moduleIds: 'named',
+        // Disable code splitting - Fastly runtime doesn't support importScripts
+        splitChunks: false,
       },
       plugins: [],
     };

src/template/context-logger.js

@@ -63,7 +63,7 @@ export function createFastlyLogger(context) {
 
   // Initialize Fastly logger module asynchronously
   // eslint-disable-next-line import/no-unresolved
-  loggerPromise = import('fastly:logger').then((module) => {
+  loggerPromise = import(/* webpackIgnore: true */ 'fastly:logger').then((module) => {
     loggerModule = module;
     loggersReady = true;
     loggerPromise = null;

src/template/edge-index.js

@@ -11,6 +11,10 @@
  */
 /* eslint-env serviceworker */
 
+// Static imports to avoid code splitting (Fastly runtime doesn't support importScripts)
+import { handleRequest as handleCloudflareRequest } from './cloudflare-adapter.js';
+import { handleRequest as handleFastlyRequest } from './fastly-adapter.js';
+
 // Platform detection based on request properties and runtime-specific modules
 let detectedPlatform = null;
 
@@ -29,7 +33,7 @@ async function detectPlatform(request) {
   // Try Fastly by checking for fastly:env module
   try {
     /* eslint-disable-next-line import/no-unresolved */
-    await import('fastly:env');
+    await import(/* webpackIgnore: true */ 'fastly:env');
     detectedPlatform = 'fastly';
     // eslint-disable-next-line no-console
     console.log('detected fastly environment');
@@ -45,13 +49,11 @@ async function getHandler(request) {
   const platform = await detectPlatform(request);
 
   if (platform === 'cloudflare') {
-    const { handleRequest } = await import('./cloudflare-adapter.js');
-    return handleRequest;
+    return handleCloudflareRequest;
   }
 
   if (platform === 'fastly') {
-    const { handleRequest } = await import('./fastly-adapter.js');
-    return handleRequest;
+    return handleFastlyRequest;
   }
 
   return null;

src/template/fastly-runtime.js

@@ -26,7 +26,7 @@ let loggerModule = null;
 export async function getFastlyEnv() {
   if (!envModule) {
     /* eslint-disable-next-line import/no-unresolved */
-    envModule = await import('fastly:env');
+    envModule = await import(/* webpackIgnore: true */ 'fastly:env');
   }
   return envModule;
 }
@@ -41,7 +41,7 @@ export async function getSecretStore() {
   }
   try {
     /* eslint-disable-next-line import/no-unresolved */
-    secretStoreModule = await import('fastly:secret-store');
+    secretStoreModule = await import(/* webpackIgnore: true */ 'fastly:secret-store');
     return secretStoreModule.SecretStore;
   } catch {
     return null;
@@ -58,7 +58,7 @@ export async function getLogger() {
   }
   try {
     /* eslint-disable-next-line import/no-unresolved */
-    loggerModule = await import('fastly:logger');
+    loggerModule = await import(/* webpackIgnore: true */ 'fastly:logger');
     return loggerModule.Logger;
   } catch {
     return null;