Fixes "after_server_start" when using return_asyncio_server. (#1676)

* Fixes ability to trigger "after_server_start", "before_server_stop", "after_server_stop" server events when using app.create_server to start your own asyncio_server
See example file run_async_advanced for a full example

* Fix a missing method on AsyncServer that some tests need
Add a tiny bit more documentation in-code
Change name of AsyncServerCoro to AsyncioServer

tests/test_server_events.py

@@ -1,3 +1,4 @@
+import asyncio
 import signal
 
 import pytest
@@ -89,3 +90,52 @@ async def test_trigger_before_events_create_server(app):
 
     assert hasattr(app, "db")
     assert isinstance(app.db, MySanicDb)
+
+def test_create_server_trigger_events(app):
+    """Test if create_server can trigger server events"""
+
+    flag1 = False
+    flag2 = False
+    flag3 = False
+
+    async def stop(app, loop):
+        nonlocal flag1
+        flag1 = True
+        await asyncio.sleep(0.1)
+        app.stop()
+
+    async def before_stop(app, loop):
+        nonlocal flag2
+        flag2 = True
+
+    async def after_stop(app, loop):
+        nonlocal flag3
+        flag3 = True
+
+    app.listener("after_server_start")(stop)
+    app.listener("before_server_stop")(before_stop)
+    app.listener("after_server_stop")(after_stop)
+
+    loop = asyncio.get_event_loop()
+    serv_coro = app.create_server(return_asyncio_server=True)
+    serv_task = asyncio.ensure_future(serv_coro, loop=loop)
+    server = loop.run_until_complete(serv_task)
+    server.after_start()
+    try:
+        loop.run_forever()
+    except KeyboardInterrupt as e:
+        loop.stop()
+    finally:
+        # Run the on_stop function if provided
+        server.before_stop()
+
+        # Wait for server to close
+        close_task = server.close()
+        loop.run_until_complete(close_task)
+
+        # Complete all tasks on the loop
+        signal.stopped = True
+        for connection in server.connections:
+            connection.close_if_idle()
+        server.after_stop()
+    assert flag1 and flag2 and flag3