Add some tests for the decider.

tests/test_decider.py

@@ -0,0 +1,35 @@
+from unittest.mock import MagicMock
+import boto.swf.layer2 as swf
+from boto.swf import layer1
+import pytest
+
+from garcon import activity
+from garcon import decider
+
+
+def mock(monkeypatch):
+    for base in [swf.Decider, swf.WorkflowType, swf.ActivityType, swf.Domain]:
+        monkeypatch.setattr(base, '__init__', MagicMock(return_value=None))
+        if base is not swf.Decider:
+            monkeypatch.setattr(base, 'register', MagicMock())
+
+
+def test_create_decider(monkeypatch):
+    """Create a decider and check the behavior of the registration.
+    """
+
+    mock(monkeypatch)
+    from tests.fixtures.flows import example
+
+    d = decider.DeciderWorker(example)
+    assert len(d.activities) == 4
+    assert d.flow
+    assert d.domain
+
+    monkeypatch.setattr(decider.DeciderWorker, 'register', MagicMock())
+    d = decider.DeciderWorker(example)
+    assert d.register.called
+
+    monkeypatch.setattr(decider.DeciderWorker, 'register', MagicMock())
+    dec = decider.DeciderWorker(example, register=False)
+    assert not dec.register.called