Celery Async Pattern Check

IMPORTANT: When this command is invoked, you MUST actually SCAN the codebase and REPORT findings. Do NOT just describe what to check.

Step 1: Find Celery Task Files

Use Glob to find task files:

{backend}/tasks/*.py
{backend}/celery_tasks/*.py

Step 2: For Each Task File, CHECK:

2.1 Find Celery Task Decorators

Look for @celery_app.task or @app.task decorators

2.2 Check for DANGEROUS Patterns

❌ Pattern 1: Using asyncio.run()

@celery_app.task
def my_task():
    return asyncio.run(async_function())  # CRASHES in production!

❌ Pattern 2: async def task

@celery_app.task
async def my_task():  # DON'T use async def for Celery tasks
    return await async_function()

❌ Pattern 3: Missing cleanup

@celery_app.task
def my_task():
    loop = asyncio.new_event_loop()
    asyncio.set_event_loop(loop)
    return loop.run_until_complete(async_function())  # Missing try/finally!

2.3 Check for CORRECT Pattern

@celery_app.task
def my_task():
    loop = asyncio.new_event_loop()
    asyncio.set_event_loop(loop)
    try:
        return loop.run_until_complete(async_function())
    finally:
        loop.close()

Step 3: Output Report

FORMAT YOUR OUTPUT EXACTLY LIKE THIS:

╔══════════════════════════════════════════════════════════════╗
║           CELERY ASYNC PATTERN COMPLIANCE REPORT             ║
╚══════════════════════════════════════════════════════════════╝

📋 TASK FILES CHECKED
────────────────────────
✅ email_tasks.py - All tasks use correct pattern
❌ sync_tasks.py - Has dangerous patterns
❌ scheduler_tasks.py - Has dangerous patterns

📊 VIOLATIONS FOUND
────────────────────────
sync_tasks.py:
  Line 15: @celery_app.task
  Line 16: def sync_users_task():
  Line 17:     return asyncio.run(...)  ❌ DANGEROUS: asyncio.run()

scheduler_tasks.py:
  Line 28: @celery_app.task
  Line 29: async def run_scheduled_job():  ❌ DANGEROUS: async def task

📊 SUMMARY
────────────────────────
Tasks checked: 8
Tasks with correct pattern: 5
Tasks with violations: 3

🔧 REQUIRED FIXES
────────────────────────
1. sync_tasks.py:sync_users_task (line 15)
   - Replace asyncio.run() with event loop pattern

2. scheduler_tasks.py:run_scheduled_job (line 28)
   - Convert from async def to sync def with event loop pattern

Step 4: Offer to Fix (If Issues Found)

If violations are found, ask: "Would you like me to fix the Celery async pattern violations?"

If user agrees, apply this pattern:

CORRECT Pattern Template:

import asyncio
from celery_app import celery_app

@celery_app.task(bind=True, max_retries=3)
def my_task(self, *args, **kwargs):
    """Task description."""
    loop = asyncio.new_event_loop()
    asyncio.set_event_loop(loop)
    try:
        return loop.run_until_complete(_async_my_task(*args, **kwargs))
    finally:
        loop.close()

async def _async_my_task(*args, **kwargs):
    """Actual async implementation."""
    # Your async code here
    pass

Why This Pattern?

When Celery runs with gevent (for concurrency), the event loop gets closed after the first async call. Subsequent calls fail with "Event loop is closed" error.

The correct pattern:

1. Creates a NEW event loop for each task execution
2. Sets it as the current loop
3. Runs the async code
4. ALWAYS closes the loop in finally block

CRITICAL REMINDER

This command MUST:

1. USE Glob to find task files
2. USE Read to examine each file
3. USE Grep to search for asyncio.run, async def tasks
4. ACTUALLY check for dangerous patterns
5. OUTPUT a structured compliance report
6. OFFER to fix violations if found

DO NOT just tell the user to run a script. PERFORM THE CHECK.