Add event ID to the SSE implementation (miguelgrinberg#213)

Author: Hamsanger

src/microdot/sse.py

@@ -12,14 +12,16 @@ def __init__(self):
         self.event = asyncio.Event()
         self.queue = []
 
-    async def send(self, data, event=None):
+    async def send(self, data, event=None, event_id=None):
         """Send an event to the client.
 
         :param data: the data to send. It can be given as a string, bytes, dict
                      or list. Dictionaries and lists are serialized to JSON.
                      Any other types are converted to string before sending.
         :param event: an optional event name, to send along with the data. If
                       given, it must be a string.
+        :param event_id: an optional event id, to send along with the data. If
+                      given, it must be a string.
         """
         if isinstance(data, (dict, list)):
             data = json.dumps(data).encode()
@@ -28,6 +30,8 @@ async def send(self, data, event=None):
         elif not isinstance(data, bytes):
             data = str(data).encode()
         data = b'data: ' + data + b'\n\n'
+        if event_id:
+            data = b'id: ' + event_id.encode() + b'\n' + data
         if event:
             data = b'event: ' + event.encode() + b'\n' + data
         self.queue.append(data)

tests/test_sse.py

@@ -23,6 +23,8 @@ def test_sse(self):
         async def handle_sse(request, sse):
             await sse.send('foo')
             await sse.send('bar', event='test')
+            await sse.send('bar', event='test', event_id='id42')
+            await sse.send('bar', event_id='id42')
             await sse.send({'foo': 'bar'})
             await sse.send([42, 'foo', 'bar'])
             await sse.send(ValueError('foo'))
@@ -34,6 +36,8 @@ async def handle_sse(request, sse):
         self.assertEqual(response.headers['Content-Type'], 'text/event-stream')
         self.assertEqual(response.text, ('data: foo\n\n'
                                          'event: test\ndata: bar\n\n'
+                                         'event: test\nid: id42\ndata: bar\n\n'
+                                         'id: id42\ndata: bar\n\n'
                                          'data: {"foo": "bar"}\n\n'
                                          'data: [42, "foo", "bar"]\n\n'
                                          'data: foo\n\n'