Fixed #870 Improved test coverage for connections.py and utils.py

tests/fixtures.py

@@ -146,3 +146,7 @@ def run_dummy_heroku_worker(sandbox, _imminent_shutdown_delay):
 
     w = TestHerokuWorker(Queue('dummy'))
     w.main_work_horse(None, None)
+
+
+class DummyQueue(object):
+    pass

tests/test_connection.py

@@ -2,7 +2,8 @@
 from __future__ import (absolute_import, division, print_function,
                         unicode_literals)
 
-from rq import Connection, Queue
+from rq import Connection, Queue, use_connection, get_current_connection, pop_connection
+from rq.connections import NoRedisConnectionException
 
 from tests import find_empty_redis_database, RQTestCase
 from tests.fixtures import do_nothing
@@ -38,3 +39,30 @@ class TestConnectionInheritance(RQTestCase):
         job2 = q2.enqueue(do_nothing)
         self.assertEqual(q1.connection, job1.connection)
         self.assertEqual(q2.connection, job2.connection)
+
+
+class TestConnectionHelpers(RQTestCase):
+    def test_use_connection(self):
+        """Test function use_connection works as expected."""
+        conn = new_connection()
+        use_connection(conn)
+
+        self.assertEqual(conn, get_current_connection())
+
+        use_connection()
+
+        self.assertNotEqual(conn, get_current_connection())
+
+        use_connection(self.testconn)  # Restore RQTestCase connection
+
+        with self.assertRaises(AssertionError):
+            with Connection(new_connection()):
+                use_connection()
+                with Connection(new_connection()):
+                    use_connection()
+
+    def test_resolve_connection_raises_on_no_connection(self):
+        """Test function resolve_connection raises if there is no connection."""
+        pop_connection()
+        with self.assertRaises(NoRedisConnectionException):
+            Queue()

tests/test_utils.py

@@ -1,9 +1,11 @@
 # -*- coding: utf-8 -*-
 from __future__ import (absolute_import, division, print_function,
                         unicode_literals)
-
-from tests import RQTestCase
-from rq.utils import parse_timeout
+import re
+import datetime
+from tests import RQTestCase, fixtures
+from rq.utils import parse_timeout, first, is_nonstring_iterable, ensure_list, utcparse, backend_class
+from rq.exceptions import TimeoutFormatError
 
 
 class TestUtils(RQTestCase):
@@ -15,3 +17,50 @@ class TestUtils(RQTestCase):
         self.assertEqual(720, parse_timeout('12m'))
         self.assertEqual(3600, parse_timeout('1h'))
         self.assertEqual(3600, parse_timeout('1H'))
+
+    def test_parse_timeout_coverage_scenarios(self):
+        """Test parse_timeout edge cases for coverage"""
+        timeouts = ['h12', 'h', 'm', 's', '10k']
+
+        self.assertEqual(None, parse_timeout(None))
+        with self.assertRaises(TimeoutFormatError):
+            for timeout in timeouts:
+                parse_timeout(timeout)
+
+    def test_first(self):
+        """Ensure function first works correctly"""
+        self.assertEqual(42, first([0, False, None, [], (), 42]))
+        self.assertEqual(None, first([0, False, None, [], ()]))
+        self.assertEqual('ohai', first([0, False, None, [], ()], default='ohai'))
+        self.assertEqual('bc', first(re.match(regex, 'abc') for regex in ['b.*', 'a(.*)']).group(1))
+        self.assertEqual(4, first([1, 1, 3, 4, 5], key=lambda x: x % 2 == 0))
+
+    def test_is_nonstring_iterable(self):
+        """Ensure function is_nonstring_iterable works correctly"""
+        self.assertEqual(True, is_nonstring_iterable([]))
+        self.assertEqual(False, is_nonstring_iterable('test'))
+        self.assertEqual(True, is_nonstring_iterable({}))
+        self.assertEqual(True, is_nonstring_iterable(()))
+
+    def test_ensure_list(self):
+        """Ensure function ensure_list works correctly"""
+        self.assertEqual([], ensure_list([]))
+        self.assertEqual(['test'], ensure_list('test'))
+        self.assertEqual({}, ensure_list({}))
+        self.assertEqual((), ensure_list(()))
+
+    def test_utcparse(self):
+        """Ensure function utcparse works correctly"""
+        utc_formated_time = '2017-08-31T10:14:02Z'
+        utc_compat_formated_time = '2017-08-31T10:20:56.226733+00:00'
+
+        self.assertEqual(datetime.datetime(2017, 8, 31, 10, 14, 2), utcparse(utc_formated_time))
+        self.assertEqual(datetime.datetime(2017, 8, 31, 10, 20, 56, 226733), utcparse(utc_compat_formated_time))
+
+    def test_backend_class(self):
+        """Ensure function backend_class works correctly"""
+        self.assertEqual(fixtures.DummyQueue, backend_class(fixtures, 'DummyQueue'))
+        self.assertNotEqual(fixtures.say_pid, backend_class(fixtures, 'DummyQueue'))
+        self.assertEqual(fixtures.DummyQueue, backend_class(fixtures, 'DummyQueue', override=fixtures.DummyQueue))
+        self.assertEqual(fixtures.DummyQueue,
+                         backend_class(fixtures, 'DummyQueue', override='tests.fixtures.DummyQueue'))