diff --git a/sitewide/test/sitewide_helpers_test.py b/sitewide/test/sitewide_helpers_test.py
new file mode 100644
index 0000000..d292b6f
--- /dev/null
+++ b/sitewide/test/sitewide_helpers_test.py
@@ -0,0 +1,170 @@
+# 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
+
+"""Unit tests for the sitewide_helpers module."""
+from __future__ import print_function
+from __future__ import division
+from __future__ import absolute_import
+
+import unittest
+
+from proto import project_pb2
+from services import service_manager
+from sitewide import sitewide_helpers
+from testing import fake
+
+
+REGULAR_USER_ID = 111
+ADMIN_USER_ID = 222
+OTHER_USER_ID = 333
+
+# Test project IDs
+REGULAR_OWNER_LIVE = 1001
+REGULAR_OWNER_ARCHIVED = 1002
+REGULAR_OWNER_DELETABLE = 1003
+REGULAR_COMMITTER_LIVE = 2001
+REGULAR_COMMITTER_ARCHIVED = 2002
+REGULAR_COMMITTER_DELETABLE = 2003
+OTHER_OWNER_LIVE = 3001
+OTHER_OWNER_ARCHIVED = 3002
+OTHER_OWNER_DELETABLE = 3003
+OTHER_COMMITTER_LIVE = 4001
+MEMBERS_ONLY = 5001
+
+
+class HelperFunctionsTest(unittest.TestCase):
+
+  def setUp(self):
+    self.services = service_manager.Services(
+        project=fake.ProjectService(),
+        user=fake.UserService(),
+        project_star=fake.ProjectStarService())
+    self.cnxn = 'fake cnxn'
+
+    for user_id in (ADMIN_USER_ID, REGULAR_USER_ID, OTHER_USER_ID):
+      self.services.user.TestAddUser('ignored_%s@gmail.com' % user_id, user_id)
+
+    self.regular_owner_live = self.services.project.TestAddProject(
+        'regular-owner-live', state=project_pb2.ProjectState.LIVE,
+        owner_ids=[REGULAR_USER_ID], project_id=REGULAR_OWNER_LIVE)
+    self.regular_owner_archived = self.services.project.TestAddProject(
+        'regular-owner-archived', state=project_pb2.ProjectState.ARCHIVED,
+        owner_ids=[REGULAR_USER_ID], project_id=REGULAR_OWNER_ARCHIVED)
+    self.regular_owner_deletable = self.services.project.TestAddProject(
+        'regular-owner-deletable', state=project_pb2.ProjectState.DELETABLE,
+        owner_ids=[REGULAR_USER_ID], project_id=REGULAR_OWNER_DELETABLE)
+    self.regular_committer_live = self.services.project.TestAddProject(
+        'regular-committer-live', state=project_pb2.ProjectState.LIVE,
+        committer_ids=[REGULAR_USER_ID], project_id=REGULAR_COMMITTER_LIVE)
+    self.regular_committer_archived = self.services.project.TestAddProject(
+        'regular-committer-archived', state=project_pb2.ProjectState.ARCHIVED,
+        committer_ids=[REGULAR_USER_ID], project_id=REGULAR_COMMITTER_ARCHIVED)
+    self.regular_committer_deletable = self.services.project.TestAddProject(
+        'regular-committer-deletable', state=project_pb2.ProjectState.DELETABLE,
+        committer_ids=[REGULAR_USER_ID], project_id=REGULAR_COMMITTER_DELETABLE)
+    self.other_owner_live = self.services.project.TestAddProject(
+        'other-owner-live', state=project_pb2.ProjectState.LIVE,
+        owner_ids=[OTHER_USER_ID], project_id=OTHER_OWNER_LIVE)
+    self.other_owner_archived = self.services.project.TestAddProject(
+        'other-owner-archived', state=project_pb2.ProjectState.ARCHIVED,
+        owner_ids=[OTHER_USER_ID], project_id=OTHER_OWNER_ARCHIVED)
+    self.other_owner_deletable = self.services.project.TestAddProject(
+        'other-owner-deletable', state=project_pb2.ProjectState.DELETABLE,
+        owner_ids=[OTHER_USER_ID], project_id=OTHER_OWNER_DELETABLE)
+    self.other_committer_live = self.services.project.TestAddProject(
+        'other-committer-live', state=project_pb2.ProjectState.LIVE,
+        committer_ids=[OTHER_USER_ID], project_id=OTHER_COMMITTER_LIVE)
+
+    self.regular_user = self.services.user.GetUser(self.cnxn, REGULAR_USER_ID)
+
+    self.admin_user = self.services.user.TestAddUser(
+        'administrator@chromium.org', ADMIN_USER_ID)
+    self.admin_user.is_site_admin = True
+
+    self.other_user = self.services.user.GetUser(self.cnxn, OTHER_USER_ID)
+
+    self.members_only_project = self.services.project.TestAddProject(
+        'members-only', owner_ids=[REGULAR_USER_ID], project_id=MEMBERS_ONLY)
+    self.members_only_project.access = project_pb2.ProjectAccess.MEMBERS_ONLY
+
+  def assertProjectsAnyOrder(self, actual_projects, *expected_projects):
+    # Check names rather than Project objects so that output is easier to read.
+    actual_names = [p.project_name for p in actual_projects]
+    expected_names = [p.project_name for p in expected_projects]
+    self.assertItemsEqual(expected_names, actual_names)
+
+  def testFilterViewableProjects_CantViewArchived(self):
+    projects = list(sitewide_helpers.FilterViewableProjects(
+        list(self.services.project.test_projects.values()),
+        self.regular_user, {REGULAR_USER_ID}))
+    self.assertProjectsAnyOrder(
+        projects, self.regular_owner_live, self.regular_committer_live,
+        self.other_owner_live, self.other_committer_live,
+        self.members_only_project)
+
+  def testFilterViewableProjects_NonMemberCantViewMembersOnly(self):
+    projects = list(sitewide_helpers.FilterViewableProjects(
+        list(self.services.project.test_projects.values()),
+        self.other_user, {OTHER_USER_ID}))
+    self.assertProjectsAnyOrder(
+        projects, self.regular_owner_live, self.regular_committer_live,
+        self.other_owner_live, self.other_committer_live)
+
+  def testFilterViewableProjects_AdminCanViewAny(self):
+    projects = list(sitewide_helpers.FilterViewableProjects(
+        list(self.services.project.test_projects.values()),
+        self.admin_user, {ADMIN_USER_ID}))
+    self.assertProjectsAnyOrder(
+        projects, self.regular_owner_live, self.regular_committer_live,
+        self.other_owner_live, self.other_committer_live,
+        self.members_only_project)
+
+  def testGetStarredProjects_OnlyViewableLiveStarred(self):
+    viewed_user_id = 123
+    for p in self.services.project.test_projects.values():
+      # We go straight to the services layer because this is a test set up
+      # rather than an actual user request.
+      self.services.project_star.SetStar(
+          self.cnxn, p.project_id, viewed_user_id, True)
+
+    self.assertProjectsAnyOrder(
+        sitewide_helpers.GetViewableStarredProjects(
+            self.cnxn, self.services, viewed_user_id,
+            {REGULAR_USER_ID}, self.regular_user),
+        self.regular_owner_live, self.regular_committer_live,
+        self.other_owner_live, self.other_committer_live,
+        self.members_only_project)
+
+  def testGetStarredProjects_MembersOnly(self):
+    # Both users were able to star the project in the past.  The stars do not
+    # go away even if access to the project changes.
+    self.services.project_star.SetStar(
+        self.cnxn, self.members_only_project.project_id, REGULAR_USER_ID, True)
+    self.services.project_star.SetStar(
+        self.cnxn, self.members_only_project.project_id, OTHER_USER_ID, True)
+
+    # But now, only one of them is currently a member, so only regular_user
+    # can see the starred project in the lists.
+    self.assertProjectsAnyOrder(
+        sitewide_helpers.GetViewableStarredProjects(
+            self.cnxn, self.services, REGULAR_USER_ID, {REGULAR_USER_ID},
+            self.regular_user),
+        self.members_only_project)
+    self.assertProjectsAnyOrder(
+        sitewide_helpers.GetViewableStarredProjects(
+            self.cnxn, self.services, OTHER_USER_ID, {REGULAR_USER_ID},
+            self.regular_user),
+        self.members_only_project)
+
+    # The other user cannot see the project, so they do not see it in either
+    # list of starred projects.
+    self.assertProjectsAnyOrder(
+        sitewide_helpers.GetViewableStarredProjects(
+            self.cnxn, self.services, REGULAR_USER_ID, {OTHER_USER_ID},
+            self.other_user))  # No expected projects listed.
+    self.assertProjectsAnyOrder(
+        sitewide_helpers.GetViewableStarredProjects(
+            self.cnxn, self.services, OTHER_USER_ID, {OTHER_USER_ID},
+            self.other_user))  # No expected projects listed.