old_contents: #!/usr/bin/env python
  import pytest
  
  import pg_bawler.core
  
  
  def test_register_handlers():
      listener = pg_bawler.core.ListenerMixin()
      assert listener.register_handler(None) == 0
      assert listener.register_handler(True) == 1
      assert listener.unregister_handler(None)
      assert not listener.unregister_handler(None)
  
  
  @pytest.mark.asyncio
  async def test_simple_listen():
  
      class NotificationListener(
          pg_bawler.core.BawlerBase,
          pg_bawler.core.ListenerMixin
      ):
          pass
  
      class NotificationSender(
          pg_bawler.core.BawlerBase,
          pg_bawler.core.SenderMixin
      ):
          pass
  
      connection_params = dict(
          dbname='bawler_test',
          user='bawler_test',
          host='postgres',
          password='postgres')
  
      nl = NotificationListener(connection_params=connection_params)
      ns = NotificationSender(connection_params=connection_params)
  
      payload = 'aaa'
      channel_name = 'pg_bawler_test'
  
      await nl.register_channel(channel='pg_bawler_test')
      await ns.send(channel=channel_name, payload=payload)
      notification = await nl.get_notification()
      assert notification.channel == channel_name
      assert notification.payload == payload
  
new_contents: #!/usr/bin/env python
  import os
  
  import pytest
  
  import pg_bawler.core
  
  
  def test_register_handlers():
      listener = pg_bawler.core.ListenerMixin()
      assert listener.register_handler(None) == 0
      assert listener.register_handler(True) == 1
      assert listener.unregister_handler(None)
      assert not listener.unregister_handler(None)
  
  
  @pytest.mark.asyncio
  async def test_simple_listen():
  
      class NotificationListener(
          pg_bawler.core.BawlerBase,
          pg_bawler.core.ListenerMixin
      ):
          pass
  
      class NotificationSender(
          pg_bawler.core.BawlerBase,
          pg_bawler.core.SenderMixin
      ):
          pass
  
      connection_params = dict(
          dbname=os.environ.get('POSTGRES_DB', 'bawler_test'),
          user=os.environ.get('POSTGRES_USER', 'postgres'),
          host=os.environ.get('POSTGRES_HOST'),
          password=os.environ.get('POSTGRES_PASSWORD', ''))
  
      nl = NotificationListener(connection_params=connection_params)
      ns = NotificationSender(connection_params=connection_params)
  
      payload = 'aaa'
      channel_name = 'pg_bawler_test'
  
      await nl.register_channel(channel='pg_bawler_test')
      await ns.send(channel=channel_name, payload=payload)
      notification = await nl.get_notification()
      assert notification.channel == channel_name
      assert notification.payload == payload
  
subject: Use env variables for postgres conn in tests