Be more informative when reporting import errors.

3 files changed, 22 insertions, 0 deletions

diff --git a/rest_framework/tests/extras/__init__.py b/rest_framework/tests/extras/__init__.py
new file mode 100644
index 00000000..e69de29b
--- /dev/null
+++ b/rest_framework/tests/extras/__init__.py
diff --git a/rest_framework/tests/extras/bad_import.py b/rest_framework/tests/extras/bad_import.py
new file mode 100644
index 00000000..68263d94
--- /dev/null
+++ b/rest_framework/tests/extras/bad_import.py
@@ -0,0 +1 @@
+raise ValueError
diff --git a/rest_framework/tests/settings.py b/rest_framework/tests/settings.py
new file mode 100644
index 00000000..0293fdc3
--- /dev/null
+++ b/rest_framework/tests/settings.py
@@ -0,0 +1,21 @@
+"""Tests for the settings module"""
+from django.test import TestCase
+
+from rest_framework.settings import APISettings, DEFAULTS, IMPORT_STRINGS
+
+
+class TestSettings(TestCase):
+    """Tests relating to the api settings"""
+
+    def test_non_import_errors(self):
+        """Make sure other errors aren't suppressed."""
+        settings = APISettings({'DEFAULT_MODEL_SERIALIZER_CLASS': 'rest_framework.tests.extras.bad_import.ModelSerializer'}, DEFAULTS, IMPORT_STRINGS)
+        with self.assertRaises(ValueError):
+            settings.DEFAULT_MODEL_SERIALIZER_CLASS
+
+    def test_import_error_message_maintained(self):
+        """Make sure real import errors are captured and raised sensibly."""
+        settings = APISettings({'DEFAULT_MODEL_SERIALIZER_CLASS': 'rest_framework.tests.extras.not_here.ModelSerializer'}, DEFAULTS, IMPORT_STRINGS)
+        with self.assertRaises(ImportError) as cm:
+            settings.DEFAULT_MODEL_SERIALIZER_CLASS
+        self.assertTrue('ImportError' in str(cm.exception))