Split model_fields tests into different files.

tests/model_fields/test_binaryfield.py

@@ -0,0 +1,28 @@
+from django.core.exceptions import ValidationError
+from django.test import TestCase
+from django.utils import six
+
+from .models import DataModel
+
+
+class BinaryFieldTests(TestCase):
+    binary_data = b'\x00\x46\xFE'
+
+    def test_set_and_retrieve(self):
+        data_set = (self.binary_data, six.memoryview(self.binary_data))
+        for bdata in data_set:
+            dm = DataModel(data=bdata)
+            dm.save()
+            dm = DataModel.objects.get(pk=dm.pk)
+            self.assertEqual(bytes(dm.data), bytes(bdata))
+            # Resave (=update)
+            dm.save()
+            dm = DataModel.objects.get(pk=dm.pk)
+            self.assertEqual(bytes(dm.data), bytes(bdata))
+            # Test default value
+            self.assertEqual(bytes(dm.short_data), b'\x08')
+
+    def test_max_length(self):
+        dm = DataModel(short_data=self.binary_data * 4)
+        with self.assertRaises(ValidationError):
+            dm.full_clean()