Integration test

integration testing only everything is working, not logic of PQ
use method
create slot attribute in constructor
corect class for test case
stop crawler in teardown method
use class
correct entity naming
python 2 adaptation
integration test with crawler and spider

tests/test_scheduler.py

@@ -2,12 +2,17 @@ import shutil
 import tempfile
 import unittest
 
+from twisted.internet import defer
+from twisted.trial.unittest import TestCase
+
 from scrapy.crawler import Crawler
 from scrapy.core.scheduler import Scheduler
 from scrapy.http import Request
 from scrapy.pqueues import _scheduler_slot_read, _scheduler_slot_write
 from scrapy.signals import request_reached_downloader, response_downloaded
 from scrapy.spiders import Spider
+from scrapy.utils.test import get_crawler
+from tests.mockserver import MockServer
 
 
 class MockCrawler(Crawler):
@@ -223,6 +228,13 @@ class TestSchedulerWithDownloaderAwareInMemory(BaseSchedulerInMemoryTester,
             self.assertEqual(len(part), len(set(part)))
 
 
+def _is_slots_unique(base_slots, result_slots):
+    unique_slots = len(set(s for _, s in base_slots))
+    for i in range(0, len(result_slots), unique_slots):
+        part = result_slots[i:i + unique_slots]
+        assert len(part) == len(set(part))
+
+
 class TestSchedulerWithDownloaderAwareOnDisk(BaseSchedulerOnDiskTester,
                                              unittest.TestCase):
     priority_queue_cls = 'scrapy.pqueues.DownloaderAwarePriorityQueue'
@@ -259,7 +271,33 @@ class TestSchedulerWithDownloaderAwareOnDisk(BaseSchedulerOnDiskTester,
                     spider=self.spider
                     )
 
-        unique_slots = len(set(s for _, s in _SLOTS))
-        for i in range(0, len(_SLOTS), unique_slots):
-            part = slots[i:i + unique_slots]
-            self.assertEqual(len(part), len(set(part)))
+        _is_slots_unique(_SLOTS, slots)
+
+
+class StartUrlsSpider(Spider):
+
+    def __init__(self, start_urls):
+        self.start_urls = start_urls
+
+
+class TestIntegrationWithDownloaderAwareOnDisk(TestCase):
+    def setUp(self):
+        self.crawler = get_crawler(
+                    StartUrlsSpider,
+                    {'SCHEDULER_PRIORITY_QUEUE': 'scrapy.pqueues.DownloaderAwarePriorityQueue',
+                     'DUPEFILTER_CLASS': 'scrapy.dupefilters.BaseDupeFilter'}
+                    )
+
+    @defer.inlineCallbacks
+    def tearDown(self):
+        yield self.crawler.stop()
+
+    @defer.inlineCallbacks
+    def test_integration_downloader_aware_priority_queue(self):
+        with MockServer() as mockserver:
+
+            url = mockserver.url("/status?n=200", is_secure=False)
+            slots = [url] * 6
+            yield self.crawler.crawl(slots)
+            self.assertEqual(self.crawler.stats.get_value('downloader/response_count'),
+                             len(slots))