Write more PluginTypeManager tests

tests/unit/test_plugin_type_manager.py

@@ -1,12 +1,26 @@
 """Tests for flake8.plugins.manager.PluginTypeManager."""
 import collections
-import mock
 
+import mock
+import pytest
+
+from flake8 import exceptions
 from flake8.plugins import manager
 
 TEST_NAMESPACE = "testing.plugin-type-manager"
 
 
+def create_plugin_mock(raise_exception=False):
+    """Create an auto-spec'd mock of a flake8 Plugin."""
+    plugin = mock.create_autospec(manager.Plugin, instance=True)
+    if raise_exception:
+        plugin.load_plugin.side_effect = exceptions.FailedToLoadPlugin(
+            plugin=mock.Mock(name='T101'),
+            exception=ValueError('Test failure'),
+        )
+    return plugin
+
+
 class TestType(manager.PluginTypeManager):
     """Fake PluginTypeManager."""
 
@@ -53,3 +67,67 @@ def test_generate_call_function():
 
     assert isinstance(func, collections.Callable)
     assert func(plugin) is optmanager
+
+
+@mock.patch('flake8.plugins.manager.PluginManager')
+def test_load_plugins(PluginManager):
+    """Verify load plugins loads *every* plugin."""
+    # Create a bunch of fake plugins
+    plugins = [create_plugin_mock(), create_plugin_mock(),
+               create_plugin_mock(), create_plugin_mock(),
+               create_plugin_mock(), create_plugin_mock(),
+               create_plugin_mock(), create_plugin_mock()]
+
+    # Have a function that will actually call the method underneath
+    def fake_map(func):
+        for plugin in plugins:
+            yield func(plugin)
+
+    # Mock out the PluginManager instance
+    manager_mock = mock.Mock(spec=['map'])
+    # Replace the map method
+    manager_mock.map = fake_map
+    # Return our PluginManager mock
+    PluginManager.return_value = manager_mock
+
+    type_mgr = TestType()
+    # Load the tests (do what we're actually testing)
+    assert len(type_mgr.load_plugins()) == 8
+    # Assert that our closure does what we think it does
+    for plugin in plugins:
+        plugin.load_plugin.assert_called_once_with()
+    assert type_mgr.plugins_loaded is True
+
+
+@mock.patch('flake8.plugins.manager.PluginManager')
+def test_load_plugins_fails(PluginManager):
+    """Verify load plugins bubbles up exceptions."""
+    plugins = [create_plugin_mock(), create_plugin_mock(True),
+               create_plugin_mock(), create_plugin_mock(),
+               create_plugin_mock(), create_plugin_mock(),
+               create_plugin_mock(), create_plugin_mock()]
+
+    # Have a function that will actually call the method underneath
+    def fake_map(func):
+        for plugin in plugins:
+            yield func(plugin)
+
+    # Mock out the PluginManager instance
+    manager_mock = mock.Mock(spec=['map'])
+    # Replace the map method
+    manager_mock.map = fake_map
+    # Return our PluginManager mock
+    PluginManager.return_value = manager_mock
+
+    type_mgr = TestType()
+    with pytest.raises(exceptions.FailedToLoadPlugin):
+        type_mgr.load_plugins()
+
+    # Assert we didn't finish loading plugins
+    assert type_mgr.plugins_loaded is False
+    # Assert the first two plugins had their load_plugin method called
+    plugins[0].load_plugin.assert_called_once_with()
+    plugins[1].load_plugin.assert_called_once_with()
+    # Assert the rest of the plugins were not loaded
+    for plugin in plugins[2:]:
+        assert plugin.load_plugin.called is False