Added test case for #3908

tests/test_exceptions.py

+from __future__ import unicode_literals
+
+from django.test import TestCase
+from django.utils.translation import ugettext_lazy as _
+
+from rest_framework.exceptions import _force_text_recursive
+
+
+class ExceptionTestCase(TestCase):
+
+    def test_force_text_recursive(self):
+
+        s = "sfdsfggiuytraetfdlklj"
+        self.assertEqual(_force_text_recursive(_(s)), s)
+        self.assertEqual(type(_force_text_recursive(_(s))), type(s))
+
+        self.assertEqual(_force_text_recursive({'a': _(s)})['a'], s)
+        self.assertEqual(type(_force_text_recursive({'a': _(s)})['a']), type(s))
+
+        self.assertEqual(_force_text_recursive([[_(s)]])[0][0], s)
+        self.assertEqual(type(_force_text_recursive([[_(s)]])[0][0]), type(s))