1 files changed, 31 insertions, 0 deletions
diff --git a/tensorflow/python/kernel_tests/constant_op_eager_test.py b/tensorflow/python/kernel_tests/constant_op_eager_test.py
index 8e9d75667d..a0d5557b92 100644
--- a/tensorflow/python/kernel_tests/constant_op_eager_test.py
+++ b/tensorflow/python/kernel_tests/constant_op_eager_test.py
@@ -32,6 +32,9 @@ from tensorflow.python.util import compat
 
 
 # TODO(josh11b): add tests with lists/tuples, Shape.
+# TODO(ashankar): Collapse with tests in constant_op_test.py and use something
+# like the test_util.run_in_graph_and_eager_modes decorator to confirm
+# equivalence between graph and eager execution.
 class ConstantTest(test.TestCase):
 
   def _testCpu(self, x):
@@ -280,6 +283,34 @@ class ConstantTest(test.TestCase):
     with self.assertRaisesRegexp(ValueError, None):
       constant_op.constant([[1, 2], [3], [4, 5]])
 
+  # TODO(ashankar): This test fails with graph construction since
+  # tensor_util.make_tensor_proto (invoked from constant_op.constant)
+  # does not handle iterables (it relies on numpy conversion).
+  # For consistency, should graph construction handle Python objects
+  # that implement the sequence protocol (but not numpy conversion),
+  # or should eager execution fail on such sequences?
+  def testCustomSequence(self):
+
+    # This is inspired by how many objects in pandas are implemented:
+    # - They implement the Python sequence protocol
+    # - But may raise a KeyError on __getitem__(self, 0)
+    # See https://github.com/tensorflow/tensorflow/issues/20347
+    class MySeq(object):
+
+      def __getitem__(self, key):
+        if key != 1 and key != 3:
+          raise KeyError(key)
+        return key
+
+      def __len__(self):
+        return 2
+
+      def __iter__(self):
+        l = list([1, 3])
+        return l.__iter__()
+
+    self.assertAllEqual([1, 3], self.evaluate(constant_op.constant(MySeq())))
+
 
 class AsTensorTest(test.TestCase):