1 files changed, 84 insertions, 0 deletions
diff --git a/lib/testtools/testtools/tests/test_tags.py b/lib/testtools/testtools/tests/test_tags.py
new file mode 100644
index 0000000000..5010f9ac12
--- /dev/null
+++ b/lib/testtools/testtools/tests/test_tags.py
@@ -0,0 +1,84 @@
+# Copyright (c) 2012 testtools developers. See LICENSE for details.
+
+"""Test tag support."""
+
+
+from testtools import TestCase
+from testtools.tags import TagContext
+
+
+class TestTags(TestCase):
+
+    def test_no_tags(self):
+        # A tag context has no tags initially.
+        tag_context = TagContext()
+        self.assertEqual(set(), tag_context.get_current_tags())
+
+    def test_add_tag(self):
+        # A tag added with change_tags appears in get_current_tags.
+        tag_context = TagContext()
+        tag_context.change_tags(set(['foo']), set())
+        self.assertEqual(set(['foo']), tag_context.get_current_tags())
+
+    def test_add_tag_twice(self):
+        # Calling change_tags twice to add tags adds both tags to the current
+        # tags.
+        tag_context = TagContext()
+        tag_context.change_tags(set(['foo']), set())
+        tag_context.change_tags(set(['bar']), set())
+        self.assertEqual(
+            set(['foo', 'bar']), tag_context.get_current_tags())
+
+    def test_change_tags_returns_tags(self):
+        # change_tags returns the current tags.  This is a convenience.
+        tag_context = TagContext()
+        tags = tag_context.change_tags(set(['foo']), set())
+        self.assertEqual(set(['foo']), tags)
+
+    def test_remove_tag(self):
+        # change_tags can remove tags from the context.
+        tag_context = TagContext()
+        tag_context.change_tags(set(['foo']), set())
+        tag_context.change_tags(set(), set(['foo']))
+        self.assertEqual(set(), tag_context.get_current_tags())
+
+    def test_child_context(self):
+        # A TagContext can have a parent.  If so, its tags are the tags of the
+        # parent at the moment of construction.
+        parent = TagContext()
+        parent.change_tags(set(['foo']), set())
+        child = TagContext(parent)
+        self.assertEqual(
+            parent.get_current_tags(), child.get_current_tags())
+
+    def test_add_to_child(self):
+        # Adding a tag to the child context doesn't affect the parent.
+        parent = TagContext()
+        parent.change_tags(set(['foo']), set())
+        child = TagContext(parent)
+        child.change_tags(set(['bar']), set())
+        self.assertEqual(set(['foo', 'bar']), child.get_current_tags())
+        self.assertEqual(set(['foo']), parent.get_current_tags())
+
+    def test_remove_in_child(self):
+        # A tag that was in the parent context can be removed from the child
+        # context without affect the parent.
+        parent = TagContext()
+        parent.change_tags(set(['foo']), set())
+        child = TagContext(parent)
+        child.change_tags(set(), set(['foo']))
+        self.assertEqual(set(), child.get_current_tags())
+        self.assertEqual(set(['foo']), parent.get_current_tags())
+
+    def test_parent(self):
+        # The parent can be retrieved from a child context.
+        parent = TagContext()
+        parent.change_tags(set(['foo']), set())
+        child = TagContext(parent)
+        child.change_tags(set(), set(['foo']))
+        self.assertEqual(parent, child.parent)
+
+
+def test_suite():
+    from unittest import TestLoader
+    return TestLoader().loadTestsFromName(__name__)