Implement robust unit test cases for message queue timing

tfw/components/frontend/message_queue_handler/message_queue_handler.py

@@ -6,6 +6,7 @@ from threading import Thread
 class MessageQueueHandler:
     keys = ['message.queue']
     type_id = 'ControlEventHandler'
+    avg_word_len = 5
 
     def __init__(self, wpm):
         self.connector = None
@@ -15,11 +16,17 @@ class MessageQueueHandler:
 
     def _dispatch_messages(self):
         for message in iter(self._queue.get, None):
-            wpm = message['wpm'] if 'wpm' in message else self.wpm
-            cps = 5 * wpm / 60
             message['typing'] = not self._queue.empty()
             self.connector.send_message(message)
-            sleep(len(message['message']) / cps)
+            self._sleep(self._get_sleep_time(message))
+
+    def _get_sleep_time(self, message):
+        words_per_min = message['wpm'] if 'wpm' in message else self.wpm
+        chars_per_min = self.avg_word_len * words_per_min / 60
+        return len(message['message']) / chars_per_min
+
+    def _sleep(self, seconds):  # pylint: disable=no-self-use
+        sleep(seconds)
 
     def handle_event(self, message, _):
         for unpacked in self._generate_messages_from_queue(message):

tfw/components/frontend/message_queue_handler/test_message_queue.py

@@ -1,8 +1,8 @@
 # pylint: disable=redefined-outer-name
-from math import inf
-from time import sleep
+from time import time
 from os import urandom
 from random import randint
+from queue import Queue
 
 import pytest
 
@@ -12,56 +12,97 @@ from .message_queue_handler import MessageQueueHandler
 class MockConnector:
     def __init__(self):
         self.callback = None
-        self.messages = []
+        self.messages = Queue()
+        self.send_times = Queue()
 
     def raise_event(self, message):
         self.callback(message, self)
-        sleep(0.01)
 
     def send_message(self, message):
-        self.messages.append(message)
+        self.messages.put(message)
+        self.send_times.put(time())
 
 
 @pytest.fixture
 def handler():
-    connector = MockConnector()
-    handler = MessageQueueHandler(inf)
-    handler.connector = connector
-    connector.callback = handler.handle_event
+    class NoSleepMessageQueueHandler(MessageQueueHandler):
+        sleep_start_times = Queue()
+        sleep_seconds = Queue()
+        sleep_end_times = Queue()
+
+        def _sleep(self, seconds):
+            self.sleep_start_times.put(time())
+            self.sleep_seconds.put(seconds)
+            super()._sleep(seconds)
+            self.sleep_end_times.put(time())
+
+    handler = NoSleepMessageQueueHandler(100000)
+    handler.connector = MockConnector()
+    handler.connector.callback = handler.handle_event
+
     handler.start()
     yield handler
     handler.cleanup()
 
 
-@pytest.fixture
-def queue():
-    yield {
+def get_message_queue(*, size=None):
+    size = randint(5, 10) if not size else size
+    return {
         'key': 'message.queue',
         'messages': [
-            {'originator': urandom(4).hex(), 'message': urandom(16).hex()}
-            for _ in range(randint(5, 10))
+            {'originator': urandom(4).hex(), 'message': urandom(randint(10, 20)).hex()}
+            for _ in range(size)
         ]
     }
 
 
-def test_message_order(handler, queue):
+def test_order(handler):
+    queue = get_message_queue()
     handler.connector.raise_event(queue)
-    old_list = queue['messages']
-    new_list = handler.connector.messages
-    length = len(old_list)
-    assert len(new_list) == length
-    for i in range(length):
-        unpacked = new_list[i]
-        assert unpacked['key'] == 'message.send'
-        assert unpacked['originator'] == old_list[i]['originator']
-        assert unpacked['typing'] == (i < length-1)
+    expected_messages = queue['messages']
+
+    actual_messages = []
+    for _ in expected_messages:
+        actual_messages.append(handler.connector.messages.get())
+
+    assert len(actual_messages) == len(expected_messages)
+    for i in range(len(expected_messages)):  # pylint: disable=consider-using-enumerate
+        message = actual_messages[i]
+        assert message['key'] == 'message.send'
+        assert message['originator'] == expected_messages[i]['originator']
+        assert message['typing'] == (i < len(expected_messages)-1)
 
 
-def test_wpm(handler, queue):
-    handler.wpm = 10000
-    handler.connector.raise_event(queue)
-    assert len(handler.connector.messages) == 1
-    handler.wpm = 100000000
-    handler.connector.raise_event(queue)
-    sleep(0.25)
-    assert len(handler.connector.messages) == 2*len(queue['messages'])
+def test_timing(handler):
+    q1 = get_message_queue(size=2)
+    q2 = get_message_queue(size=2)
+    handler.connector.raise_event(q1)
+    handler.connector.raise_event(q2)
+
+    messages = []
+    send_times = []
+    sleep_start_times = []
+    sleep_seconds = []
+    sleep_end_times = []
+    for _ in range(len(q1['messages']) + len(q2['messages'])):
+        messages.append(handler.connector.messages.get())
+        send_times.append(handler.connector.send_times.get())
+        sleep_start_times.append(handler.sleep_start_times.get())
+        sleep_seconds.append(handler.sleep_seconds.get())
+        sleep_end_times.append(handler.sleep_end_times.get())
+
+    # no sleep before first message
+    assert sleep_start_times[0] > send_times[0]
+    assert messages[0]['typing']
+
+    # at least 'seconds' sleep before sending next messages
+    assert (send_times[0] + sleep_seconds[0]) < sleep_end_times[0]
+    assert (send_times[0] + sleep_seconds[0]) < send_times[1]
+    assert messages[1]['typing']
+    assert (send_times[1] + sleep_seconds[1]) < sleep_end_times[1]
+    assert (send_times[1] + sleep_seconds[1]) < send_times[2]
+    assert messages[2]['typing']
+
+    # at least 'seconds' sleep after last message
+    assert (send_times[2] + sleep_seconds[2]) < sleep_end_times[3]
+    assert not messages[3]['typing']