implement property carousel for profile switching

test/property/test_property_carousel.py

@@ -0,0 +1,78 @@
+from unittest import TestCase
+from unittest.mock import Mock
+from owrx.property import PropertyCarousel, PropertyLayer, PropertyDeleted
+
+
+class PropertyCarouselTest(TestCase):
+    def testInitiallyEmpty(self):
+        pc = PropertyCarousel()
+        with self.assertRaises(KeyError):
+            x = pc["testkey"]
+
+    def testPropertyAccess(self):
+        pc = PropertyCarousel()
+        pl = PropertyLayer(testkey="testvalue")
+        pc.addLayer("test", pl)
+        pc.switch("test")
+        self.assertEqual(pc["testkey"], "testvalue")
+
+    def testWriteAccess(self):
+        pc = PropertyCarousel()
+        pl = PropertyLayer(testkey="old_value")
+        pc.addLayer("test", pl)
+        pc.switch("test")
+        pc["testkey"] = "new_value"
+        self.assertEqual(pc["testkey"], "new_value")
+        self.assertEqual(pl["testkey"], "new_value")
+
+    def testForwardsEvents(self):
+        pc = PropertyCarousel()
+        pl = PropertyLayer(testkey="old_value")
+        pc.addLayer("test", pl)
+        pc.switch("test")
+        mock = Mock()
+        pc.wire(mock.method)
+        pc["testkey"] = "new_value"
+        mock.method.assert_called_once_with({"testkey": "new_value"})
+
+    def testStopsForwardingAfterSwitch(self):
+        pc = PropertyCarousel()
+        pl_x = PropertyLayer(testkey="old_value")
+        pc.addLayer("x", pl_x)
+        pl_y = PropertyLayer(testkey="new_value")
+        pc.addLayer("y", pl_y)
+        pc.switch("x")
+        pc.switch("y")
+        mock = Mock()
+        pc.wire(mock.method)
+        pl_x["testkey"] = "new_value"
+        mock.method.assert_not_called()
+
+    def testEventsOnSwitch(self):
+        pc = PropertyCarousel()
+        pl_x = PropertyLayer(old_key="old_value")
+        pc.addLayer("x", pl_x)
+        pl_y = PropertyLayer(new_key="new_value")
+        pc.addLayer("y", pl_y)
+        pc.switch("x")
+        mock = Mock()
+        pc.wire(mock.method)
+        pc.switch("y")
+        mock.method.assert_called_once_with({"old_key": PropertyDeleted, "new_key": "new_value"})
+
+    def testNoEventsIfKeysDontChange(self):
+        pc = PropertyCarousel()
+        pl_x = PropertyLayer(testkey="same_value")
+        pc.addLayer("x", pl_x)
+        pl_y = PropertyLayer(testkey="same_value")
+        pc.addLayer("y", pl_y)
+        pc.switch("x")
+        mock = Mock()
+        pc.wire(mock.method)
+        pc.switch("y")
+        mock.method.assert_not_called()
+
+    def testKeyErrorOnInvalidSwitch(self):
+        pc = PropertyCarousel()
+        with self.assertRaises(KeyError):
+            pc.switch("doesntmatter")