Merge branch 'rules'

rigidity/rules.py

@@ -43,6 +43,50 @@ def apply(self, value):
         return buffer.value
 
 
+class Boolean(Rule):
+    '''
+    Cast a string as a boolean value.
+    '''
+    ACTION_ERROR = 1
+    ACTION_DEFAULT = 2
+    ACTION_DROPROW = 3
+
+    def __init__(self, allow_null=False, action=ACTION_ERROR, default=None):
+        self.allow_null = allow_null
+        self.default = default
+        self.action = action
+
+    def apply(self, value):
+        lvalue = str(value).lower()
+        if lvalue in ('true', 'yes', 't', '1'):
+            return True
+        elif lvalue in ('false', 'no', 'f', '0'):
+            return False
+        elif self.allow_null and lvalue in ('null', 'none', ''):
+            return None
+        else:
+            if self.action == self.ACTION_ERROR:
+                raise ValueError('Value was not a boolean value')
+            elif self.action == self.ACTION_DEFAULT:
+                return self.default
+            elif self.action == self.ACTION_DROPROW:
+                raise rigidity.errors.DropRow()
+            else:
+                raise ValueError('Value was not a boolean value')
+
+
+class Bytes(Rule):
+    '''
+    Encode a string as a bytes object.
+    '''
+
+    def __init__(self, encoding='utf8'):
+        self.encoding = encoding
+
+    def apply(self, value):
+        return bytes(value, self.encoding)
+
+
 class Contains(Rule):
     '''
     Check that a string field value contains the string (or all strings

tests/test_rules.py

@@ -15,6 +15,64 @@ def test_apply(self):
         self.assertEqual(self.rule.apply('hello'), 'hello')
 
 
+class TestBoolean(unittest.TestCase):
+
+    def test_apply_string_boolean(self):
+        rule = rules.Boolean()
+        self.assertTrue(rule.apply('true'))
+        self.assertTrue(rule.apply('yes'))
+        self.assertTrue(rule.apply('t'))
+        self.assertTrue(rule.apply('1'))
+        self.assertFalse(rule.apply('false'))
+        self.assertFalse(rule.apply('no'))
+        self.assertFalse(rule.apply('f'))
+        self.assertFalse(rule.apply('0'))
+        self.assertRaises(ValueError, rule.apply, 'null')
+        self.assertRaises(ValueError, rule.apply, 'none')
+        self.assertRaises(ValueError, rule.apply, '')
+
+    def test_apply_invalid_boolean(self):
+        rule = rules.Boolean()
+        self.assertRaises(ValueError, rule.apply, 'a')
+
+    def test_apply_allow_null(self):
+        rule = rules.Boolean(allow_null=True)
+        self.assertIs(None, rule.apply('null'))
+        self.assertIs(None, rule.apply('none'))
+        self.assertIs(None, rule.apply(''))
+
+    def test_apply_action_default(self):
+        rule = rules.Boolean(action=rules.Boolean.ACTION_DEFAULT, default='t')
+        self.assertEqual('t', rule.apply('a'))
+
+    def test_apply_action_droprow(self):
+        rule = rules.Boolean(action=rules.Boolean.ACTION_DROPROW)
+        self.assertRaises(errors.DropRow, rule.apply, 'a')
+
+    def test_apply_action_invalid(self):
+        rule = rules.Boolean(action=None)
+        self.assertRaises(ValueError, rule.apply, 'a')
+
+
+class TestBytes(unittest.TestCase):
+
+    def test_apply(self):
+        rule = rules.Bytes()
+        self.assertEqual(rule.apply('hello'), b'hello')
+
+    def test_apply_utf16(self):
+        rule = rules.Bytes('utf16')
+        self.assertEqual(rule.apply('hello'), 'hello'.encode('utf16'))
+
+    def test_apply_encoding_mismatch(self):
+        '''
+        Attempt to encode a unicode character with the ASCII encoding
+        and assert that this raises an error.
+        '''
+        rule = rules.Bytes('ascii')
+        self.assertRaises(ValueError, rule.apply, 'ጷ')
+
+
 class TestCapitalizeWords(unittest.TestCase):
 
     def test_apply(self):