2 files changed, 26 insertions, 0 deletions
diff --git a/absl/testing/parameterized.py b/absl/testing/parameterized.py
index a7cc88b..b67aaeb 100755
--- a/absl/testing/parameterized.py
+++ b/absl/testing/parameterized.py
@@ -281,6 +281,10 @@ class _ParameterizedTestIter(object):
           testcase_params = {k: v for k, v in six.iteritems(testcase_params)
                              if k != _NAMED_DICT_KEY}
         elif _non_string_or_bytes_iterable(testcase_params):
+          if not isinstance(testcase_params[0], six.string_types):
+            raise RuntimeError(
+                'The first element of named test parameters is the test name '
+                'suffix and must be a string')
           testcase_name = testcase_params[0]
           testcase_params = testcase_params[1:]
         else:
diff --git a/absl/testing/tests/parameterized_test.py b/absl/testing/tests/parameterized_test.py
index 4235675..85f8e9b 100755
--- a/absl/testing/tests/parameterized_test.py
+++ b/absl/testing/tests/parameterized_test.py
@@ -677,6 +677,28 @@ class ParameterizedTestsTest(absltest.TestCase):
         def test_mixed_something(self, unused_obj):
           pass
 
+  def test_named_test_with_no_name_fails(self):
+    with self.assertRaises(RuntimeError):
+
+      class _(parameterized.TestCase):
+
+        @parameterized.named_parameters(
+            (0,),
+        )
+        def test_something(self, unused_obj):
+          pass
+
+  def test_named_test_dict_with_no_name_fails(self):
+    with self.assertRaises(RuntimeError):
+
+      class _(parameterized.TestCase):
+
+        @parameterized.named_parameters(
+            {'unused_obj': 0},
+        )
+        def test_something(self, unused_obj):
+          pass
+
   def test_parameterized_test_iter_has_testcases_property(self):
     @parameterized.parameters(1, 2, 3, 4, 5, 6)
     def test_something(unused_self, unused_obj):  # pylint: disable=invalid-name