Device: raise an exception if there's unexpected arguments (issue #84)

Do not accept *args and **kwargs on the base Device class.  These were
unused arguments anyway.  This will cause an exception to be raise if
a device is constructed with arguments that are not used by any of its
parent classes.  This prevents the user from accidentally constructing
a device with incorrect arguments because of a typo.

Author: carandraug

doc/examples.rst

@@ -61,7 +61,7 @@ Configurations
   from microscope.testsuite.devices import TestFilterWheel
 
   DEVICES = [
-      device(TestCamera, '127.0.0.1', 8005, {'otherargs' : 1}),
+      device(TestCamera, '127.0.0.1', 8005, {'buffer_length' : 0}),
       device(TestLaser, '127.0.0.1', 8006),
       device(TestFilterWheel, '127.0.0.1', 8007,
              {'filters' : [(0, 'GFP', 525), (1, 'RFP'), (2, 'Cy5')]}),

microscope/devices.py

@@ -199,7 +199,7 @@ class Device(object):
     """
     __metaclass__ = abc.ABCMeta
 
-    def __init__(self, index=None, *args, **kwargs):
+    def __init__(self, index=None):
         self.enabled = None
         # A list of settings. (Can't serialize OrderedDict, so use {}.)
         self.settings = OrderedDict()

microscope/testsuite/deviceserver_test.py

@@ -80,7 +80,7 @@ def tearDown(self):
 
 class TestStarting(BaseTestServeDevices):
     DEVICES = [
-        device(TestCamera, '127.0.0.1', 8001, {'otherargs' : 1}),
+        device(TestCamera, '127.0.0.1', 8001, {'buffer_length' : 0}),
         device(TestFilterWheel, '127.0.0.1', 8003,
                {'filters' : [(0, 'GFP', 525), (1, 'RFP'), (2, 'Cy5')]}),
     ]

microscope/testsuite/test_devices.py

@@ -42,6 +42,7 @@
 import numpy
 import serial
 
+import microscope.devices
 import microscope.testsuite.devices as dummies
 import microscope.testsuite.mock_devices as mocks
 
@@ -488,5 +489,23 @@ def setUp(self):
         self.device = dummies.DummyDSP()
 
 
+class TestBaseDevice(unittest.TestCase):
+    def test_unexpected_kwargs_raise_exception(self):
+        """Unexpected kwargs on constructor raise exception.
+
+        Test first that we can construct the device.  Then test that
+        it fails if there's a typo on the argument.  See issue #84.
+        """
+        filters = [(0, 'DAPI', '430')]
+        dummies.TestFilterWheel(filters=filters)
+        ## XXX: Device.__del__ calls shutdown().  However, if __init__
+        ## failed the device is not complete and shutdown() fails
+        ## because the logger has not been created.  See comments on
+        ## issue #69.  patch __del__ to workaround this issue.
+        with unittest.mock.patch('microscope.devices.Device.__del__'):
+            with self.assertRaisesRegex(TypeError, "argument 'filteres'"):
+                dummies.TestFilterWheel(filteres=filters)
+
+
 if __name__ == '__main__':
     unittest.main()