The List validator now passes with objects implementing the list

interface.

refs #18

booby/validators.py

@@ -27,6 +27,7 @@
 
 import re
 import functools
+import collections
 
 from booby import errors
 
@@ -181,7 +182,7 @@ def __init__(self, *validators):
         self.validators = validators
 
     def validate(self, value):
-        if not isinstance(value, list):
+        if not isinstance(value, collections.MutableSequence):
             raise errors.ValidationError('should be a list')
 
         for i in value:

tests/unit/validators/test_list.py

@@ -0,0 +1,58 @@
+# -*- coding: utf-8 -*-
+
+from __future__ import unicode_literals
+import collections
+
+from expects import expect
+from .._helpers import stub_validator
+
+from booby import validators, errors
+
+
+class TestList(object):
+    def test_should_pass_if_value_is_a_list(self):
+        self.validator(['foo', 'bar'])
+
+    def test_should_pass_if_value_is_a_mutable_sequence(self):
+        self.validator(MyList('foo', 'bar'))
+
+    def test_should_fail_if_value_is_not_a_list(self):
+        expect(lambda: self.validator(object())).to.raise_error(
+            errors.ValidationError, 'should be a list')
+
+    def test_should_fail_if_value_is_none(self):
+        expect(lambda: self.validator(None)).to.raise_error(
+            errors.ValidationError, 'should be a list')
+
+    def test_should_fail_if_inner_validator_fails(self):
+        def inner_validator(value):
+            if value == 'bar':
+                raise errors.ValidationError('invalid')
+
+        self.validator = validators.List(stub_validator, inner_validator)
+
+        expect(lambda: self.validator(['foo', 'bar'])).to.raise_error(
+            errors.ValidationError, 'invalid')
+
+    def setup(self):
+        self.validator = validators.List()
+
+
+class MyList(collections.MutableSequence):
+    def __init__(self, *args):
+        self._store = list(args)
+
+    def __getitem__(self, index):
+        return self._store[index]
+
+    def __setitem__(self, index, value):
+        pass
+
+    def __delitem__(self, index):
+        pass
+
+    def __len__(self):
+        pass
+
+    def insert(self, index, value):
+        pass

tests/unit/validators/test_validators.py

@@ -112,31 +112,5 @@ def setup(self):
         self.validator = validators.Model(User)
 
 
-class TestList(object):
-    def test_when_value_is_not_a_list_then_raises_validation_error(self):
-        expect(lambda: self.validator(object())).to.raise_error(
-            errors.ValidationError, 'should be a list')
-
-    def test_when_value_is_none_then_raises_validation_error(self):
-        expect(lambda: self.validator(None)).to.raise_error(
-            errors.ValidationError, 'should be a list')
-
-    def test_when_value_is_a_list_then_does_not_raise(self):
-        self.validator(['foo', 'bar'])
-
-    def test_when_inner_validator_raises_validation_error_then_raises_validation_error(self):
-        def inner_validator(value):
-            if value == 'bar':
-                raise errors.ValidationError('invalid')
-
-        self.validator = validators.List(stub_validator, inner_validator)
-
-        expect(lambda: self.validator(['foo', 'bar'])).to.raise_error(
-            errors.ValidationError, 'invalid')
-
-    def setup(self):
-        self.validator = validators.List()
-
-
 class User(models.Model):
     name = fields.String()