Check string length range constraints.

cassandra/cqlengine/columns.py

@@ -343,6 +343,12 @@ class Text(Column):
                 raise ValueError(
                     'Maximum length is not allowed to be negative.')
 
+        if self.min_length is not None and self.max_length is not None:
+            if self.max_length < self.min_length:
+                raise ValueError(
+                    'Maximum length must be greater or equal '
+                    'to minimum length.')
+
         super(Text, self).__init__(**kwargs)
 
     def validate(self, value):

tests/integration/cqlengine/columns/test_validation.py

@@ -392,6 +392,18 @@ class TestAscii(BaseCassEngTestCase):
         with self.assertRaises(ValueError):
             Ascii(max_length=-1)
 
+    def test_length_range(self):
+        Ascii(min_length=0, max_length=0)
+        Ascii(min_length=0, max_length=1)
+        Ascii(min_length=10, max_length=10)
+        Ascii(min_length=10, max_length=11)
+
+        with self.assertRaises(ValueError):
+            Ascii(min_length=10, max_length=9)
+
+        with self.assertRaises(ValueError):
+            Ascii(min_length=1, max_length=0)
+
     def test_type_checking(self):
         Ascii().validate('string')
         Ascii().validate(u'unicode')
@@ -416,12 +428,30 @@ class TestAscii(BaseCassEngTestCase):
 
     def test_required_validation(self):
         """ Tests that validation raise on none and blank values if value required. """
+        Ascii(required=True).validate('k')
+
         with self.assertRaises(ValidationError):
             Ascii(required=True).validate('')
 
         with self.assertRaises(ValidationError):
             Ascii(required=True).validate(None)
 
+        # With min_length set.
+        Ascii(required=True, min_length=0).validate('k')
+        Ascii(required=True, min_length=1).validate('k')
+
+        with self.assertRaises(ValidationError):
+            Ascii(required=True, min_length=2).validate('k')
+
+        # With max_length set.
+        Ascii(required=True, max_length=1).validate('k')
+
+        with self.assertRaises(ValidationError):
+            Ascii(required=True, max_length=2).validate('kevin')
+
+        with self.assertRaises(ValueError):
+            Ascii(required=True, max_length=0)
+
 
 class TestText(BaseCassEngTestCase):
 
@@ -477,6 +507,18 @@ class TestText(BaseCassEngTestCase):
         with self.assertRaises(ValueError):
             Text(max_length=-1)
 
+    def test_length_range(self):
+        Text(min_length=0, max_length=0)
+        Text(min_length=0, max_length=1)
+        Text(min_length=10, max_length=10)
+        Text(min_length=10, max_length=11)
+
+        with self.assertRaises(ValueError):
+            Text(min_length=10, max_length=9)
+
+        with self.assertRaises(ValueError):
+            Text(min_length=1, max_length=0)
+
     def test_type_checking(self):
         Text().validate('string')
         Text().validate(u'unicode')
@@ -501,12 +543,30 @@ class TestText(BaseCassEngTestCase):
 
     def test_required_validation(self):
         """ Tests that validation raise on none and blank values if value required. """
+        Text(required=True).validate('b')
+
         with self.assertRaises(ValidationError):
             Text(required=True).validate('')
 
         with self.assertRaises(ValidationError):
             Text(required=True).validate(None)
 
+        # With min_length set.
+        Text(required=True, min_length=0).validate('b')
+        Text(required=True, min_length=1).validate('b')
+
+        with self.assertRaises(ValidationError):
+            Text(required=True, min_length=2).validate('b')
+
+        # With max_length set.
+        Text(required=True, max_length=1).validate('b')
+
+        with self.assertRaises(ValidationError):
+            Text(required=True, max_length=2).validate('blake')
+
+        with self.assertRaises(ValueError):
+            Text(required=True, max_length=0)
+
 
 class TestExtraFieldsRaiseException(BaseCassEngTestCase):
     class TestModel(Model):