Improve async signal tests.

tests/test_signals.py

@@ -1,8 +1,9 @@
+from pytest import mark
 from twisted.internet import defer
 from twisted.trial import unittest
 
 from scrapy import signals, Request, Spider
-from scrapy.utils.test import get_crawler
+from scrapy.utils.test import get_crawler, get_from_asyncio_queue
 
 from tests.mockserver import MockServer
 
@@ -11,12 +12,12 @@ class ItemSpider(Spider):
     name = 'itemspider'
 
     def start_requests(self):
-        for _ in range(10):
-            yield Request(self.mockserver.url('/status?n=200'),
-                          dont_filter=True)
+        for index in range(10):
+            yield Request(self.mockserver.url('/status?n=200&id=%d' % index),
+                          meta={'index': index})
 
     def parse(self, response):
-        return {'field': 42}
+        return {'index': response.meta['index']}
 
 
 class AsyncSignalTestCase(unittest.TestCase):
@@ -29,11 +30,15 @@ class AsyncSignalTestCase(unittest.TestCase):
         self.mockserver.__exit__(None, None, None)
 
     async def _on_item_scraped(self, item):
+        item = await get_from_asyncio_queue(item)
         self.items.append(item)
 
+    @mark.only_asyncio()
     @defer.inlineCallbacks
     def test_simple_pipeline(self):
         crawler = get_crawler(ItemSpider)
         crawler.signals.connect(self._on_item_scraped, signals.item_scraped)
         yield crawler.crawl(mockserver=self.mockserver)
         self.assertEqual(len(self.items), 10)
+        for index in range(10):
+            self.assertIn({'index': index}, self.items)