Add tests on the capped queue

Author: MickaelBergem

tests/test_core.py

@@ -0,0 +1,45 @@
+from unittest.mock import patch
+from queue import Queue
+from howfast_apm import core
+
+
+def test_capped_queue(example_queue_items_gen):
+    """ CoreAPM.save_point should add items in the queue """
+    # TODO: find a better way to replace this queue object
+    core.queue = Queue(maxsize=10)
+    # Save one point
+    assert core.queue.qsize() == 0
+    core.CoreAPM.save_point(*next(example_queue_items_gen))
+    assert core.queue.qsize() == 1
+
+    # Save a second point
+    core.CoreAPM.save_point(*next(example_queue_items_gen))
+    assert core.queue.qsize() == 2
+
+    # Fill the queue
+    for i in range(8):
+        item = list(next(example_queue_items_gen))
+        item[3] = f'/call/{i}'  # update the URL to keep track of points
+        core.CoreAPM.save_point(*item)
+    assert core.queue.qsize() == 10
+    assert core.queue.full()
+
+    next_item = core.queue.get_nowait()
+    assert next_item
+
+
+def test_capped_queue_full(example_queue_item):
+    """ CoreAPM.save_point should discard old items should the queue be full """
+    # TODO: find a better way to replace this queue object
+    core.queue = Queue(maxsize=10)
+    # Fill the queue
+    for i in range(10):
+        item = list(example_queue_item)
+        item[3] = f'/call/{i}'  # update the URL to keep track of points
+        core.CoreAPM.save_point(*item)
+    assert core.queue.full()
+
+    # Add one more item to the full queue
+    core.CoreAPM.save_point(*example_queue_item)
+    assert core.queue.full(), 'queue should still be full'
+    assert core.queue.qsize() == 10