quicknotes/.cursor/rules/process-cleanup.mdc

---
description: Guidelines for proper process cleanup in Node/Bun scripts
globs: **/*.{js,ts}
---
<rule>
When managing long-running processes in Node/Bun scripts:

1. Always track processes globally:
   ```js
   let currentProcess = null;
   ```

2. Set up cleanup handlers at the top level:
   ```js
   // Basic cleanup
   process.on('exit', () => {
     if (currentProcess?.exitCode === null) {
       currentProcess.kill('SIGTERM');
     }
   });

   // Handle interrupts
   ['SIGINT', 'SIGTERM'].forEach(signal => {
     process.on(signal, () => {
       if (currentProcess?.exitCode === null) {
         currentProcess.kill('SIGTERM');
       }
       process.exit();
     });
   });
   ```

3. Always check process state before killing:
   ```js
   if (process?.exitCode === null) {
     process.kill('SIGTERM');
   }
   ```

4. Use timeouts for process startup:
   ```js
   const startupTimeout = setTimeout(() => {
     if (process.exitCode === null) {
       process.kill('SIGTERM');
     }
     reject(new Error('Process startup timeout'));
   }, timeoutMs);
   ```

5. Clean up in both try/catch and finally blocks:
   ```js
   try {
     // ... process work ...
   } catch (error) {
     cleanup();
     throw error;
   } finally {
     cleanup();
   }
   ```

metadata:
  priority: high
  version: 1.0
</rule>

examples:
  - input: |
      # Starting a server process
      const server = spawn('server');
    output: |
      let currentServer = null;
      process.on('exit', () => {
        if (currentServer?.exitCode === null) {
          currentServer.kill('SIGTERM');
        }
      });
      const server = spawn('server');
      currentServer = server;