1 files changed, 54 insertions, 0 deletions
diff --git a/tests/unit/test_notifier.py b/tests/unit/test_notifier.py
new file mode 100644
index 0000000..6a162cf
--- /dev/null
+++ b/tests/unit/test_notifier.py
@@ -0,0 +1,54 @@
+"""Unit tests for the Notifier object."""
+import pytest
+
+from flake8.plugins import notifier
+
+
+class _Listener(object):
+    def __init__(self, error_code):
+        self.error_code = error_code
+        self.was_notified = False
+
+    def notify(self, error_code, *args, **kwargs):
+        assert error_code.startswith(self.error_code)
+        self.was_notified = True
+
+
+class TestNotifier(object):
+    """Notifier unit tests."""
+
+    @pytest.fixture(autouse=True)
+    def setup(self):
+        """Set up each TestNotifier instance."""
+        self.notifier = notifier.Notifier()
+        self.listener_map = {}
+
+        def add_listener(error_code):
+            listener = _Listener(error_code)
+            self.listener_map[error_code] = listener
+            self.notifier.register_listener(error_code, listener)
+
+        for i in range(10):
+            add_listener('E{0}'.format(i))
+            for j in range(30):
+                add_listener('E{0}{1:02d}'.format(i, j))
+
+    def test_notify(self):
+        """Show that we notify a specific error code."""
+        self.notifier.notify('E111', 'extra', 'args')
+        assert self.listener_map['E111'].was_notified is True
+        assert self.listener_map['E1'].was_notified is True
+
+    @pytest.mark.parametrize('code', ['W123', 'W12', 'W1', 'W'])
+    def test_no_listeners_for(self, code):
+        """Show that we return an empty list of listeners."""
+        assert list(self.notifier.listeners_for(code)) == []
+
+    @pytest.mark.parametrize('code,expected', [
+        ('E101', ['E101', 'E1']),
+        ('E211', ['E211', 'E2']),
+    ])
+    def test_listeners_for(self, code, expected):
+        """Verify that we retrieve the correct listeners."""
+        assert ([l.error_code for l in self.notifier.listeners_for(code)] ==
+                expected)