Split model_fields tests into different files.

tests/model_fields/test_slugfield.py

@@ -0,0 +1,25 @@
+# -*- coding: utf-8 -*-
+from __future__ import unicode_literals
+
+from django.test import TestCase
+
+from .models import BigS, UnicodeSlugField
+
+
+class SlugFieldTests(TestCase):
+
+    def test_slugfield_max_length(self):
+        """
+        SlugField honors max_length.
+        """
+        bs = BigS.objects.create(s='slug' * 50)
+        bs = BigS.objects.get(pk=bs.pk)
+        self.assertEqual(bs.s, 'slug' * 50)
+
+    def test_slugfield_unicode_max_length(self):
+        """
+        SlugField with allow_unicode=True honors max_length.
+        """
+        bs = UnicodeSlugField.objects.create(s='你好你好' * 50)
+        bs = UnicodeSlugField.objects.get(pk=bs.pk)
+        self.assertEqual(bs.s, '你好你好' * 50)