--- a/py/test.py	Mon Nov 26 23:21:03 2012 +0800
+++ b/py/test.py	Thu Nov 29 23:50:40 2012 +0800
@@ -1,11 +1,15 @@
+#!/usr/bin/env python2.7
+import StringIO
+
 import unittest
 import sensor_ds18b20
+import params
 
 class TestSensors(unittest.TestCase):
     def setUp(self):
         self.sensors = sensor_ds18b20.DS18B20s(None)
 
-    def test_re(self):
+    def test_sensors_regex(self):
         f1 = """6e 01 4b 46 7f ff 02 10 71 : crc=71 YES
 6e 01 4b 46 7f ff 02 10 71 t=22875
 """
@@ -24,4 +28,47 @@
         val = self.sensors.do_sensor_name('blank', f3)
         self.assertEqual(val, -0.001)
 
+class TestParams(unittest.TestCase):
+    def setUp(self):
+        self.params = params.Params()
+
+    def test_params_basic(self):
+        defparams = params.Params()
+        self.assertEqual(defparams.overshoot_factor, 
+            params._FIELD_DEFAULTS['overshoot_factor'])
+
+        # fetching a bad parameter fails
+        with self.assertRaises(KeyError):
+            x = self.params.param_that_doesnt_exist
+
+        # setting a parameter
+        defparams.overshoot_factor = 8877
+        self.assertEqual(defparams.overshoot_factor, 8877)
+
+        # setting a bad parameter fails
+        with self.assertRaises(KeyError):
+            self.params.somewrongthing = 5
+
+    def test_params_load(self):
+        jsbuf = StringIO.StringIO('{"fridge_setpoint": 999}')
+
+        self.params.load(f=jsbuf)
+        self.assertEqual(self.params.fridge_setpoint, 999)
+
+        with self.assertRaises(params.Params.Error):
+            jsbuf = StringIO.StringIO('{"something_else": 999}')
+            self.params.load(f=jsbuf)
+
+        with self.assertRaises(KeyError):
+            x = self.params.something_else
+
+    def test_params_save(self):
+        jsbuf = StringIO.StringIO()
+
+        self.params.overshoot_delay = 123
+        self.params.save(f=jsbuf)
+
+        s = jsbuf.getvalue()
+        self.assertTrue('"overshoot_delay": 123' in s, msg=s)
+            
 unittest.main()