Added 'incorrect' tests for mode, source and dest.

These arguments have a fixed sets of allowed values. The tests
are checking that the code correctly displays error information
when an unexpected argument value is supplied.

Utils/Dataflow/pyDKB/dataflow/stage/tests/test_ProcessorStage.py

@@ -155,6 +155,21 @@ def test_input_files(self):
         self.args['input_files'] = ['something', 'something_else']
         self.check_args()
 
+    def test_m_incorrect(self):
+        [msg, result] = isolate_function_error(self.stage.parse_args,
+                                               ['-m', 'i'])
+        err = "error: argument -m/--mode: invalid choice: 'i' "\
+              "(choose from 'f', 's', 'm')"
+        self.assertIn(err, msg)
+
+    def test_mode_incorrect(self):
+        [msg, result] = isolate_function_error(self.stage.parse_args,
+                                               ['--mode',
+                                                'incorrect'])
+        err = "error: argument -m/--mode: invalid choice: 'incorrect' "\
+              "(choose from 'f', 's', 'm')"
+        self.assertIn(err, msg)
+
 
 def add_arg(arg, val, short=False):
     def f(self):
@@ -170,6 +185,25 @@ def f(self):
         setattr(ProcessorStageArgsTestCase, 'test_%s_%s' % (arg, val), f)
 
 
+def add_arg_incorrect(arg, vals, short=False):
+    if short:
+        val = 'i'
+        args = ['-' + arg[0], val]
+        fname = 'test_%s_%s' % (arg[0], val)
+    else:
+        val = 'incorrect'
+        args = ['--' + arg, val]
+        fname = 'test_%s_%s' % (arg, val)
+
+    def f(self):
+        [msg, result] = isolate_function_error(self.stage.parse_args, args)
+        err = "error: argument -%s/--%s: invalid choice: '%s' "\
+              "(choose from %s)" % (arg[0], arg, val,
+                                    ', '.join(["'%s'" % c for c in vals]))
+        self.assertIn(err, msg)
+    setattr(ProcessorStageArgsTestCase, fname, f)
+
+
 def add_mode(val, short=False):
     def f(self):
         if short:
@@ -226,6 +260,8 @@ def f(self):
         add_override_hdfs(a, v)
         for m in modes:
             add_override_mode(a, v, m)
+    add_arg_incorrect(a, args_to_add[a], True)
+    add_arg_incorrect(a, args_to_add[a])
 
 
 for m in modes: