diff --git a/features/test/features_bizobj_test.py b/features/test/features_bizobj_test.py
new file mode 100644
index 0000000..1814ae2
--- /dev/null
+++ b/features/test/features_bizobj_test.py
@@ -0,0 +1,134 @@
+# Copyright 2016 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style
+# license that can be found in the LICENSE file or at
+# https://developers.google.com/open-source/licenses/bsd
+
+"""Tests for features bizobj functions."""
+from __future__ import print_function
+from __future__ import division
+from __future__ import absolute_import
+
+import unittest
+
+from proto import features_pb2
+from features import features_bizobj
+from testing import fake
+
+class FeaturesBizobjTest(unittest.TestCase):
+
+  def setUp(self):
+    self.local_ids = [1, 2, 3, 4, 5]
+    self.issues = [fake.MakeTestIssue(1000, local_id, '', 'New', 111)
+                   for local_id in self.local_ids]
+    self.hotlistitems = [features_pb2.MakeHotlistItem(
+        issue.issue_id, rank=rank*10, adder_id=111, date_added=3) for
+                           rank, issue in enumerate(self.issues)]
+    self.iids = [item.issue_id for item in self.hotlistitems]
+
+  def testIssueIsInHotlist(self):
+    hotlist = features_pb2.Hotlist(items=self.hotlistitems)
+    for issue in self.issues:
+      self.assertTrue(features_bizobj.IssueIsInHotlist(hotlist, issue.issue_id))
+
+    self.assertFalse(features_bizobj.IssueIsInHotlist(
+        hotlist, fake.MakeTestIssue(1000, 9, '', 'New', 111)))
+
+  def testSplitHotlistIssueRanks(self):
+    iid_rank_tuples = [(issue.issue_id, issue.rank)
+                       for issue in self.hotlistitems]
+    iid_rank_tuples.reverse()
+    ret = features_bizobj.SplitHotlistIssueRanks(
+        100003, True, iid_rank_tuples)
+    self.assertEqual(ret, (iid_rank_tuples[:2], iid_rank_tuples[2:]))
+
+    iid_rank_tuples.reverse()
+    ret = features_bizobj.SplitHotlistIssueRanks(
+        100003, False, iid_rank_tuples)
+    self.assertEqual(ret, (iid_rank_tuples[:3], iid_rank_tuples[3:]))
+
+    # target issue not found
+    first_pairs, second_pairs = features_bizobj.SplitHotlistIssueRanks(
+        100009, True, iid_rank_tuples)
+    self.assertEqual(iid_rank_tuples, first_pairs)
+    self.assertEqual(second_pairs, [])
+
+  def testGetOwnerIds(self):
+    hotlist = features_pb2.Hotlist(owner_ids=[111])
+    self.assertEqual(features_bizobj.GetOwnerIds(hotlist), [111])
+
+  def testUsersInvolvedInHotlists_Empty(self):
+    self.assertEqual(set(), features_bizobj.UsersInvolvedInHotlists([]))
+
+  def testUsersInvolvedInHotlists_Normal(self):
+    hotlist1 = features_pb2.Hotlist(
+        owner_ids=[111, 222], editor_ids=[333, 444, 555],
+        follower_ids=[123])
+    hotlist2 = features_pb2.Hotlist(
+        owner_ids=[111], editor_ids=[222, 123])
+    self.assertEqual(set([111, 222, 333, 444, 555, 123]),
+                     features_bizobj.UsersInvolvedInHotlists([hotlist1,
+                                                              hotlist2]))
+
+  def testUserIsInHotlist(self):
+    h = features_pb2.Hotlist()
+    self.assertFalse(features_bizobj.UserIsInHotlist(h, {9}))
+    self.assertFalse(features_bizobj.UserIsInHotlist(h, set()))
+
+    h.owner_ids.extend([1, 2, 3])
+    h.editor_ids.extend([4, 5, 6])
+    h.follower_ids.extend([7, 8, 9])
+    self.assertTrue(features_bizobj.UserIsInHotlist(h, {1}))
+    self.assertTrue(features_bizobj.UserIsInHotlist(h, {4}))
+    self.assertTrue(features_bizobj.UserIsInHotlist(h, {7}))
+    self.assertFalse(features_bizobj.UserIsInHotlist(h, {10}))
+
+    # Membership via group membership
+    self.assertTrue(features_bizobj.UserIsInHotlist(h, {10, 4}))
+
+    # Membership via several group memberships
+    self.assertTrue(features_bizobj.UserIsInHotlist(h, {1, 4}))
+
+    # Several irrelevant group memberships
+    self.assertFalse(features_bizobj.UserIsInHotlist(h, {10, 11, 12}))
+
+  def testDetermineHotlistIssuePosition(self):
+    # normal
+    prev_iid, index, next_iid = features_bizobj.DetermineHotlistIssuePosition(
+        self.issues[2], self.iids)
+    self.assertEqual(prev_iid, self.hotlistitems[1].issue_id)
+    self.assertEqual(index, 2)
+    self.assertEqual(next_iid, self.hotlistitems[3].issue_id)
+
+    # end of list
+    prev_iid, index, next_iid = features_bizobj.DetermineHotlistIssuePosition(
+        self.issues[4], self.iids)
+    self.assertEqual(prev_iid, self.hotlistitems[3].issue_id)
+    self.assertEqual(index, 4)
+    self.assertEqual(next_iid, None)
+
+    # beginning of list
+    prev_iid, index, next_iid = features_bizobj.DetermineHotlistIssuePosition(
+        self.issues[0], self.iids)
+    self.assertEqual(prev_iid, None)
+    self.assertEqual(index, 0)
+    self.assertEqual(next_iid, self.hotlistitems[1].issue_id)
+
+    # one item in list
+    prev_iid, index, next_iid = features_bizobj.DetermineHotlistIssuePosition(
+        self.issues[2], [self.iids[2]])
+    self.assertEqual(prev_iid, None)
+    self.assertEqual(index, 0)
+    self.assertEqual(next_iid, None)
+
+    prev_iid, index, next_iid = features_bizobj.DetermineHotlistIssuePosition(
+        self.issues[2], [self.iids[3]])
+    self.assertEqual(prev_iid, None)
+    self.assertEqual(index, None)
+    self.assertEqual(next_iid, None)
+
+    #none
+    prev_iid, index, next_iid = features_bizobj.DetermineHotlistIssuePosition(
+        self.issues[2], [])
+    self.assertEqual(prev_iid, None)
+    self.assertEqual(index, None)
+    self.assertEqual(next_iid, None)