Fixed tests to reflect desired configuration behaviour

Test for when environment variable and configuration file
variable both set now tests that the environment variable takes
precedence

Removed logic that would never be triggered from
lib/ansible/constants.py

lib/ansible/constants.py

@@ -29,8 +29,6 @@ def get_config(p, section, key, env_var, default):
         try:
             return p.get(section, key)
         except:
-            if env_var is not None:
-                return os.environ.get(env_var, default)
             return default
     else:
         return default

test/TestConstants.py

+# -*- coding: utf-8 -*-
+
+import unittest
+
+from ansible.constants import get_config
+import ConfigParser
+import random
+import string
+import os
+
+
+def random_string(length):
+    return ''.join(random.choice(string.ascii_uppercase) for x in range(6))
+
+p = ConfigParser.ConfigParser()
+p.read(os.path.join(os.path.dirname(__file__), 'ansible.cfg'))
+
+class TestConstants(unittest.TestCase):
+
+    #####################################
+    ### get_config unit tests
+
+    
+    def test_configfile_and_env_both_set(self):
+        r = random_string(6)
+        env_var = 'ANSIBLE_TEST_%s' % r
+        os.environ[env_var] = r
+
+        res = get_config(p, 'defaults', 'test_key', env_var, 'default')
+        del os.environ[env_var]
+
+        assert res == r
+
+
+    def test_configfile_set_env_not_set(self):
+        r = random_string(6)
+        env_var = 'ANSIBLE_TEST_%s' % r
+        assert env_var not in os.environ
+        
+        res = get_config(p, 'defaults', 'test_key', env_var, 'default')
+
+        print res
+        assert res == 'test_value'
+
+
+    def test_configfile_not_set_env_set(self):
+        r = random_string(6)
+        env_var = 'ANSIBLE_TEST_%s' % r
+        os.environ[env_var] = r
+
+        res = get_config(p, 'defaults', 'doesnt_exist', env_var, 'default')
+        del os.environ[env_var]
+
+        assert res == r
+
+
+    def test_configfile_not_set_env_not_set(self):
+        r = random_string(6)
+        env_var = 'ANSIBLE_TEST_%s' % r
+        assert env_var not in os.environ
+        
+        res = get_config(p, 'defaults', 'doesnt_exist', env_var, 'default')
+
+        assert res == 'default'

test/ansible.cfg

+[defaults]
+
+test_key = test_value