Add simple file store backend

tests/test_file.py

@@ -0,0 +1,42 @@
+# standard imports
+import unittest
+import tempfile
+import os
+
+# local imports
+from shep.persist import PersistedState
+from shep.store.file import SimpleFileStoreFactory
+from shep.error import (
+        StateExists,
+        StateInvalid,
+        )
+
+
+class TestStateReport(unittest.TestCase):
+        
+    def setUp(self):
+        self.d = tempfile.mkdtemp()
+        self.factory = SimpleFileStoreFactory(self.d)
+        self.states = PersistedState(self.factory.add, 4)
+        self.states.add('foo') 
+        self.states.add('bar') 
+        self.states.add('baz') 
+
+
+    def test_add(self):
+        self.states.put('abcd', self.states.FOO)
+        fp = os.path.join(self.d, 'FOO', 'abcd')
+        f = open(fp, 'r')
+        v = f.read()
+        f.close()
+        self.assertEqual(len(v), 0)
+
+
+    def test_dup(self):
+        self.states.put('abcd', self.states.FOO)
+        with self.assertRaises(FileExistsError):
+            self.states.put('abcd', self.states.FOO)
+       
+
+if __name__ == '__main__':
+    unittest.main()