🤖 fix: update test fixtures to use correct Runtime API

- Use runtime.exec() instead of non-existent writeFile(path, content, options)
- All fixtures now use bash commands for file operations
- Rebuilt types so fixtures see updated Extension interface (returns unknown)
- Tests still pass

Author: ammar-agent

tests/extensions/fixtures/folder-extension/index.ts

@@ -12,10 +12,10 @@ const extension: Extension = {
   async onPostToolUse(payload: PostToolUseHookPayload) {
     const { runtime, result } = payload;
 
-    // Use runtime.writeFile API
-    await runtime.writeFile(
-      ".cmux/folder-ext-ran.txt",
-      "folder-based extension executed\n"
+    // Use runtime.exec() for file operations
+    await runtime.exec(
+      `mkdir -p .cmux && echo 'folder-based extension executed' > .cmux/folder-ext-ran.txt`,
+      { cwd: ".", timeout: 5 }
     );
 
     // Return result unmodified

tests/extensions/fixtures/simple-logger.ts

@@ -17,12 +17,13 @@ const extension: Extension = {
       toolName,
       toolCallId,
       workspaceId,
-    }) + "\n";
-
-    // Use runtime.writeFile API (extensions have full Runtime access)
-    await runtime.writeFile(".cmux/extension-log.txt", logEntry, {
-      mode: "append",
     });
+
+    // Use runtime.exec() for file operations
+    await runtime.exec(
+      `mkdir -p .cmux && echo ${JSON.stringify(logEntry)} >> .cmux/extension-log.txt`,
+      { cwd: ".", timeout: 5 }
+    );
 
     // Return result unmodified
     return result;

tests/extensions/fixtures/working-extension.ts

@@ -12,10 +12,10 @@ const extension: Extension = {
   async onPostToolUse(payload: PostToolUseHookPayload) {
     const { runtime, result } = payload;
 
-    // Use runtime.writeFile API
-    await runtime.writeFile(
-      ".cmux/working-ext-ran.txt",
-      "working extension executed\n"
+    // Use runtime.exec() for file operations
+    await runtime.exec(
+      `mkdir -p .cmux && echo 'working extension executed' > .cmux/working-ext-ran.txt`,
+      { cwd: ".", timeout: 5 }
     );
 
     // Return result unmodified