aiofastforward 0.0.1

Patched versions of loop.time, loop.call_later, loop.call_at, and asyncio.sleep

aiofastfoward

Gives the ability to fast-forward time by providing patched versions of loop.call_later, loop.call_at, loop.time, and asyncio.sleep. This allows you to test asynchronous code synchronously.

Usage

loop.call_later

# Production code
async def schedule_callback(loop, callback):
    loop.call_later(1, callback, 0)
    loop.call_later(2, callback, 1)

# Test code
from unittest.mock import Mock, call
loop = asyncio.get_running_loop()

with aiofastfoward.FastForward(loop) as forward:
    callback = Mock()
    await schedule_callback(loop, callback)

    await forward(1)
    self.assertEqual(callback.mock_calls, [call(0)])
    await forward(1)
    self.assertEqual(callback.mock_calls, [call(0), call(1)])

asyncio.sleep

# Production code
async def sleeper(callback):
    await asyncio.sleep(1)
    await asyncio.sleep(2)
    callback(0)

# Test code
loop = asyncio.get_running_loop()
callback = Mock()

with aiofastforward.FastForward(loop) as forward:
    asyncio.create_task(sleeper())

    await forward(3)
    self.assertEqual(callback.mock_calls, [call(0)])