test: Verify interface implementations. Remove TODO from cd35bd4.

scrapyd/scheduler.py

@@ -13,7 +13,6 @@ def __init__(self, config):
 
     def schedule(self, project, spider_name, priority=0.0, **spider_args):
         q = self.queues[project]
-        # priority passed as kw for compat w/ custom queue. TODO use pos in 1.4
         q.add(spider_name, priority=priority, **spider_args)
 
     def list_projects(self):

tests/test_interfaces.py

@@ -0,0 +1,28 @@
+import pytest
+from twisted.cred.checkers import ICredentialsChecker
+from twisted.cred.portal import IRealm
+from zope.interface.verify import verifyClass
+
+from scrapyd.basicauth import PublicHTMLRealm, StringCredentialsChecker
+from scrapyd.eggstorage import FilesystemEggStorage
+from scrapyd.environ import Environment
+from scrapyd.interfaces import IEggStorage, IEnvironment, IJobStorage, IPoller, ISpiderQueue, ISpiderScheduler
+from scrapyd.jobstorage import MemoryJobStorage, SqliteJobStorage
+from scrapyd.poller import QueuePoller
+from scrapyd.scheduler import SpiderScheduler
+from scrapyd.spiderqueue import SqliteSpiderQueue
+
+
+@pytest.mark.parametrize('cls,interface', [
+    (PublicHTMLRealm, IRealm),
+    (StringCredentialsChecker, ICredentialsChecker),
+    (FilesystemEggStorage, IEggStorage),
+    (Environment, IEnvironment),
+    (MemoryJobStorage, IJobStorage),
+    (SqliteJobStorage, IJobStorage),
+    (QueuePoller, IPoller),
+    (SpiderScheduler, ISpiderScheduler),
+    (SqliteSpiderQueue, ISpiderQueue),
+])
+def test_interface(cls, interface):
+    verifyClass(interface, cls)