Improve password complexity messaging

Send password form instructions that include password complexity and
also send error messages back that include all parts of the
complexity instead of single parts at a time.

And clean up phrasing to be more consistent.

common/djangoapps/util/tests/test_password_policy_validators.py

@@ -1,31 +1,67 @@
 """Tests for util.password_policy_validators module."""
 
+import mock
 import unittest
 
+from ddt import data, ddt, unpack
+from django.conf import settings
 from django.core.exceptions import ValidationError
 from django.test.utils import override_settings
 
-from util.password_policy_validators import validate_password_dictionary
+from util.password_policy_validators import password_instructions, validate_password, _validate_password_dictionary
 
 
+@ddt
 class PasswordPolicyValidatorsTestCase(unittest.TestCase):
     """ Tests for password validator utility functions """
 
     @override_settings(PASSWORD_DICTIONARY_EDIT_DISTANCE_THRESHOLD=2)
     @override_settings(PASSWORD_DICTIONARY=['testme'])
+    @mock.patch.dict(settings.FEATURES, {'ENFORCE_PASSWORD_POLICY': True})
     def test_validate_password_dictionary(self):
         """ Tests dictionary checks """
         # Direct match
         with self.assertRaises(ValidationError):
-            validate_password_dictionary('testme')
+            _validate_password_dictionary('testme')
 
         # Off by one
         with self.assertRaises(ValidationError):
-            validate_password_dictionary('estme')
+            _validate_password_dictionary('estme')
 
         # Off by two
         with self.assertRaises(ValidationError):
-            validate_password_dictionary('bestmet')
+            _validate_password_dictionary('bestmet')
 
         # Off by three (should pass)
-        validate_password_dictionary('bestem')
+        _validate_password_dictionary('bestem')
+
+    @data(
+        (u'', 'at least 2 characters & 2 letters & 1 number.'),
+        (u'a.', 'at least 2 letters & 1 number.'),
+        (u'a1', 'at least 2 letters.'),
+        (u'aa1', None),
+    )
+    @unpack
+    @override_settings(PASSWORD_COMPLEXITY={'ALPHABETIC': 2, 'NUMERIC': 1})
+    @mock.patch.dict(settings.FEATURES, {'ENFORCE_PASSWORD_POLICY': True})
+    def test_validation_errors(self, password, msg):
+        """ Tests validate_password error messages """
+        if msg is None:
+            validate_password(password)
+        else:
+            with self.assertRaises(ValidationError) as cm:
+                validate_password(password)
+            self.assertIn(msg, cm.exception.message)
+
+    @data(
+        ({}, 'at least 2 characters.'),
+        ({'ALPHABETIC': 2}, 'characters, including 2 letters.'),
+        ({'ALPHABETIC': 2, 'NUMERIC': 1}, 'characters, including 2 letters & 1 number.'),
+        ({'NON ASCII': 2, 'NUMERIC': 1, 'UPPER': 3}, 'including 3 uppercase letters & 1 number & 2 symbols.'),
+    )
+    @unpack
+    @mock.patch.dict(settings.FEATURES, {'ENFORCE_PASSWORD_POLICY': True})
+    def test_password_instruction(self, config, msg):
+        """ Tests password_instruction """
+        with override_settings(PASSWORD_COMPLEXITY=config):
+            self.assertIn(msg, password_instructions())