Refactor checker manager and add tests

1 files changed, 18 insertions, 4 deletions

diff --git a/tests/unit/test_checker_manager.py b/tests/unit/test_checker_manager.py
index 2d3143e..7e622bc 100644
--- a/tests/unit/test_checker_manager.py
+++ b/tests/unit/test_checker_manager.py
@@ -7,11 +7,18 @@ import pytest
 from flake8 import checker
 
 
+def style_guide_mock(**kwargs):
+    kwargs.setdefault('diff', False)
+    kwargs.setdefault('jobs', '4')
+    style_guide = mock.Mock()
+    style_guide.options = mock.Mock(**kwargs)
+    return style_guide
+
+
 def test_oserrors_cause_serial_fall_back():
     """Verify that OSErrors will cause the Manager to fallback to serial."""
     err = OSError(errno.ENOSPC, 'Ominous message about spaceeeeee')
-    style_guide = mock.Mock()
-    style_guide.options = mock.Mock(diff=False, jobs='4')
+    style_guide = style_guide_mock()
     with mock.patch('multiprocessing.Queue', side_effect=err):
         manager = checker.Manager(style_guide, [], [])
     assert manager.using_multiprocessing is False
@@ -20,8 +27,15 @@ def test_oserrors_cause_serial_fall_back():
 def test_oserrors_are_reraised():
     """Verify that OSErrors will cause the Manager to fallback to serial."""
     err = OSError(errno.EAGAIN, 'Ominous message')
-    style_guide = mock.Mock()
-    style_guide.options = mock.Mock(diff=False, jobs='4')
+    style_guide = style_guide_mock()
     with mock.patch('multiprocessing.Queue', side_effect=err):
         with pytest.raises(OSError):
             checker.Manager(style_guide, [], [])
+
+
+def test_multiprocessing_is_disabled():
+    """Verify not being able to import multiprocessing forces jobs to 0."""
+    style_guide = style_guide_mock()
+    with mock.patch('flake8.checker.multiprocessing', None):
+        manager = checker.Manager(style_guide, [], [])
+        assert manager.jobs == 0