Reorganize SWF tests so they're shorter and easier to use

tests/test_swf/models/test_history_event.py

@@ -0,0 +1,29 @@
+from sure import expect
+from freezegun import freeze_time
+
+from moto.swf.models import HistoryEvent
+
+
+@freeze_time("2015-01-01 12:00:00")
+def test_history_event_creation():
+    he = HistoryEvent(123, "DecisionTaskStarted", scheduled_event_id=2)
+    he.event_id.should.equal(123)
+    he.event_type.should.equal("DecisionTaskStarted")
+    he.event_timestamp.should.equal(1420110000.0)
+
+@freeze_time("2015-01-01 12:00:00")
+def test_history_event_to_dict_representation():
+    he = HistoryEvent(123, "DecisionTaskStarted", scheduled_event_id=2)
+    he.to_dict().should.equal({
+        "eventId": 123,
+        "eventType": "DecisionTaskStarted",
+        "eventTimestamp": 1420110000.0,
+        "decisionTaskStartedEventAttributes": {
+            "scheduledEventId": 2
+        }
+    })
+
+def test_history_event_breaks_on_initialization_if_not_implemented():
+    HistoryEvent.when.called_with(
+        123, "UnknownHistoryEvent"
+    ).should.throw(NotImplementedError)