diff --git a/tracker/test/issuedetailezt_test.py b/tracker/test/issuedetailezt_test.py
new file mode 100644
index 0000000..d3b8327
--- /dev/null
+++ b/tracker/test/issuedetailezt_test.py
@@ -0,0 +1,306 @@
+# 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
+
+"""Unittests for monorail.tracker.issuedetailezt."""
+from __future__ import print_function
+from __future__ import division
+from __future__ import absolute_import
+
+import logging
+import mock
+import mox
+import time
+import unittest
+
+import settings
+from businesslogic import work_env
+from proto import features_pb2
+from features import hotlist_views
+from features import send_notifications
+from framework import authdata
+from framework import exceptions
+from framework import framework_views
+from framework import framework_helpers
+from framework import urls
+from framework import permissions
+from framework import profiler
+from framework import sorting
+from framework import template_helpers
+from proto import project_pb2
+from proto import tracker_pb2
+from proto import user_pb2
+from services import service_manager
+from services import issue_svc
+from services import tracker_fulltext
+from testing import fake
+from testing import testing_helpers
+from tracker import issuedetailezt
+from tracker import tracker_constants
+from tracker import tracker_helpers
+
+
+class GetAdjacentIssueTest(unittest.TestCase):
+
+  def setUp(self):
+    self.cnxn = 'fake cnxn'
+    self.services = service_manager.Services(
+        config=fake.ConfigService(),
+        issue=fake.IssueService(),
+        user=fake.UserService(),
+        project=fake.ProjectService(),
+        issue_star=fake.IssueStarService(),
+        spam=fake.SpamService())
+    self.services.project.TestAddProject('proj', project_id=789)
+    self.mr = testing_helpers.MakeMonorailRequest()
+    self.mr.auth.user_id = 111
+    self.mr.auth.effective_ids = {111}
+    self.mr.me_user_id = 111
+    self.work_env = work_env.WorkEnv(
+      self.mr, self.services, 'Testing phase')
+
+  def testGetAdjacentIssue_PrevIssue(self):
+    cur_issue = fake.MakeTestIssue(789, 2, 'sum', 'New', 111, issue_id=78902)
+    next_issue = fake.MakeTestIssue(789, 3, 'sum', 'New', 111, issue_id=78903)
+    prev_issue = fake.MakeTestIssue(789, 1, 'sum', 'New', 111, issue_id=78901)
+    self.services.issue.TestAddIssue(cur_issue)
+    self.services.issue.TestAddIssue(next_issue)
+    self.services.issue.TestAddIssue(prev_issue)
+
+    with self.work_env as we:
+      we.FindIssuePositionInSearch = mock.Mock(
+          return_value=[78901, 1, 78903, 3])
+
+      actual_issue = issuedetailezt.GetAdjacentIssue(
+         self.mr, we, cur_issue)
+      self.assertEqual(prev_issue, actual_issue)
+      we.FindIssuePositionInSearch.assert_called_once_with(cur_issue)
+
+  def testGetAdjacentIssue_NextIssue(self):
+    cur_issue = fake.MakeTestIssue(789, 2, 'sum', 'New', 111, issue_id=78902)
+    next_issue = fake.MakeTestIssue(789, 3, 'sum', 'New', 111, issue_id=78903)
+    prev_issue = fake.MakeTestIssue(789, 1, 'sum', 'New', 111, issue_id=78901)
+    self.services.issue.TestAddIssue(cur_issue)
+    self.services.issue.TestAddIssue(next_issue)
+    self.services.issue.TestAddIssue(prev_issue)
+
+    with self.work_env as we:
+      we.FindIssuePositionInSearch = mock.Mock(
+          return_value=[78901, 1, 78903, 3])
+
+      actual_issue = issuedetailezt.GetAdjacentIssue(
+          self.mr, we, cur_issue, next_issue=True)
+      self.assertEqual(next_issue, actual_issue)
+      we.FindIssuePositionInSearch.assert_called_once_with(cur_issue)
+
+  def testGetAdjacentIssue_NotFound(self):
+    cur_issue = fake.MakeTestIssue(789, 2, 'sum', 'New', 111, issue_id=78902)
+    prev_issue = fake.MakeTestIssue(789, 1, 'sum', 'New', 111, issue_id=78901)
+    self.services.issue.TestAddIssue(cur_issue)
+    self.services.issue.TestAddIssue(prev_issue)
+
+    with self.work_env as we:
+      we.FindIssuePositionInSearch = mock.Mock(
+          return_value=[78901, 1, 78903, 3])
+
+      with self.assertRaises(exceptions.NoSuchIssueException):
+        issuedetailezt.GetAdjacentIssue(
+            self.mr, we, cur_issue, next_issue=True)
+      we.FindIssuePositionInSearch.assert_called_once_with(cur_issue)
+
+  def testGetAdjacentIssue_Hotlist(self):
+    cur_issue = fake.MakeTestIssue(789, 2, 'sum', 'New', 111, issue_id=78902)
+    next_issue = fake.MakeTestIssue(789, 3, 'sum', 'New', 111, issue_id=78903)
+    prev_issue = fake.MakeTestIssue(789, 1, 'sum', 'New', 111, issue_id=78901)
+    self.services.issue.TestAddIssue(cur_issue)
+    self.services.issue.TestAddIssue(next_issue)
+    self.services.issue.TestAddIssue(prev_issue)
+    hotlist = fake.Hotlist('name', 678, owner_ids=[111])
+
+    with self.work_env as we:
+      we.GetIssuePositionInHotlist = mock.Mock(
+          return_value=[78901, 1, 78903, 3])
+
+      actual_issue = issuedetailezt.GetAdjacentIssue(
+          self.mr, we, cur_issue, hotlist=hotlist, next_issue=True)
+      self.assertEqual(next_issue, actual_issue)
+      we.GetIssuePositionInHotlist.assert_called_once_with(
+          cur_issue, hotlist, self.mr.can, self.mr.sort_spec,
+          self.mr.group_by_spec)
+
+
+class FlipperRedirectTest(unittest.TestCase):
+
+  def setUp(self):
+    self.services = service_manager.Services(
+        config=fake.ConfigService(),
+        features=fake.FeaturesService(),
+        issue=fake.IssueService(),
+        user=fake.UserService(),
+        project=fake.ProjectService())
+    self.project = self.services.project.TestAddProject(
+      'proj', project_id=987, committer_ids=[111])
+    self.next_servlet = issuedetailezt.FlipperNext(
+        'req', 'res', services=self.services)
+    self.prev_servlet = issuedetailezt.FlipperPrev(
+        'req', 'res', services=self.services)
+    self.list_servlet = issuedetailezt.FlipperList(
+        'req', 'res', services=self.services)
+    mr = testing_helpers.MakeMonorailRequest(project=self.project)
+    mr.local_id = 123
+    mr.me_user_id = 111
+
+    self.next_servlet.mr = mr
+    self.prev_servlet.mr = mr
+    self.list_servlet.mr = mr
+
+    self.fake_issue_1 = fake.MakeTestIssue(987, 123, 'summary', 'New', 111,
+        project_name='rutabaga')
+    self.services.issue.TestAddIssue(self.fake_issue_1)
+    self.fake_issue_2 = fake.MakeTestIssue(987, 456, 'summary', 'New', 111,
+        project_name='rutabaga')
+    self.services.issue.TestAddIssue(self.fake_issue_2)
+    self.fake_issue_3 = fake.MakeTestIssue(987, 789, 'summary', 'New', 111,
+        project_name='potato')
+    self.services.issue.TestAddIssue(self.fake_issue_3)
+
+    self.next_servlet.redirect = mock.Mock()
+    self.prev_servlet.redirect = mock.Mock()
+    self.list_servlet.redirect = mock.Mock()
+
+  @mock.patch('tracker.issuedetailezt.GetAdjacentIssue')
+  def testFlipperNext(self, patchGetAdjacentIssue):
+    patchGetAdjacentIssue.return_value = self.fake_issue_2
+    self.next_servlet.mr.GetIntParam = mock.Mock(return_value=None)
+
+    self.next_servlet.get(project_name='proj', viewed_username=None)
+    self.next_servlet.mr.GetIntParam.assert_called_once_with('hotlist_id')
+    patchGetAdjacentIssue.assert_called_once()
+    self.next_servlet.redirect.assert_called_once_with(
+      '/p/rutabaga/issues/detail?id=456')
+
+  @mock.patch('tracker.issuedetailezt.GetAdjacentIssue')
+  def testFlipperNext_Hotlist(self, patchGetAdjacentIssue):
+    patchGetAdjacentIssue.return_value = self.fake_issue_3
+    self.next_servlet.mr.GetIntParam = mock.Mock(return_value=123)
+    # TODO(jeffcarp): Mock hotlist_id param on path here.
+
+    self.next_servlet.get(project_name='proj', viewed_username=None)
+    self.next_servlet.mr.GetIntParam.assert_called_with('hotlist_id')
+    self.next_servlet.redirect.assert_called_once_with(
+      '/p/potato/issues/detail?id=789')
+
+  @mock.patch('tracker.issuedetailezt.GetAdjacentIssue')
+  def testFlipperPrev(self, patchGetAdjacentIssue):
+    patchGetAdjacentIssue.return_value = self.fake_issue_2
+    self.next_servlet.mr.GetIntParam = mock.Mock(return_value=None)
+
+    self.prev_servlet.get(project_name='proj', viewed_username=None)
+    self.prev_servlet.mr.GetIntParam.assert_called_with('hotlist_id')
+    patchGetAdjacentIssue.assert_called_once()
+    self.prev_servlet.redirect.assert_called_once_with(
+      '/p/rutabaga/issues/detail?id=456')
+
+  @mock.patch('tracker.issuedetailezt.GetAdjacentIssue')
+  def testFlipperPrev_Hotlist(self, patchGetAdjacentIssue):
+    patchGetAdjacentIssue.return_value = self.fake_issue_3
+    self.prev_servlet.mr.GetIntParam = mock.Mock(return_value=123)
+    # TODO(jeffcarp): Mock hotlist_id param on path here.
+
+    self.prev_servlet.get(project_name='proj', viewed_username=None)
+    self.prev_servlet.mr.GetIntParam.assert_called_with('hotlist_id')
+    self.prev_servlet.redirect.assert_called_once_with(
+      '/p/potato/issues/detail?id=789')
+
+  @mock.patch('tracker.issuedetailezt._ComputeBackToListURL')
+  def testFlipperList(self, patch_ComputeBackToListURL):
+    patch_ComputeBackToListURL.return_value = '/p/test/issues/list'
+    self.list_servlet.mr.GetIntParam = mock.Mock(return_value=None)
+
+    self.list_servlet.get()
+
+    self.list_servlet.mr.GetIntParam.assert_called_with('hotlist_id')
+    patch_ComputeBackToListURL.assert_called_once()
+    self.list_servlet.redirect.assert_called_once_with(
+      '/p/test/issues/list')
+
+  @mock.patch('tracker.issuedetailezt._ComputeBackToListURL')
+  def testFlipperList_Hotlist(self, patch_ComputeBackToListURL):
+    patch_ComputeBackToListURL.return_value = '/p/test/issues/list'
+    self.list_servlet.mr.GetIntParam = mock.Mock(return_value=123)
+
+    self.list_servlet.get()
+
+    self.list_servlet.mr.GetIntParam.assert_called_with('hotlist_id')
+    self.list_servlet.redirect.assert_called_once_with(
+      '/p/test/issues/list')
+
+
+class ShouldShowFlipperTest(unittest.TestCase):
+
+  def setUp(self):
+    self.cnxn = 'fake cnxn'
+
+  def VerifyShouldShowFlipper(
+      self, expected, query, sort_spec, can, create_issues=0):
+    """Instantiate a _Flipper and check if makes a pipeline or not."""
+    services = service_manager.Services(
+        config=fake.ConfigService(),
+        issue=fake.IssueService(),
+        project=fake.ProjectService(),
+        user=fake.UserService())
+    project = services.project.TestAddProject(
+      'proj', project_id=987, committer_ids=[111])
+    mr = testing_helpers.MakeMonorailRequest(project=project)
+    mr.query = query
+    mr.sort_spec = sort_spec
+    mr.can = can
+    mr.project_name = project.project_name
+    mr.project = project
+
+    for idx in range(create_issues):
+      _created_issue = fake.MakeTestIssue(
+          project.project_id,
+          idx,
+          'summary_%d' % idx,
+          'status',
+          111,
+          reporter_id=111)
+      services.issue.TestAddIssue(_created_issue)
+
+    self.assertEqual(expected, issuedetailezt._ShouldShowFlipper(mr, services))
+
+  def testShouldShowFlipper_RegularSizedProject(self):
+    # If the user is looking for a specific issue, no flipper.
+    self.VerifyShouldShowFlipper(
+        False, '123', '', tracker_constants.OPEN_ISSUES_CAN)
+    self.VerifyShouldShowFlipper(False, '123', '', 5)
+    self.VerifyShouldShowFlipper(
+        False, '123', 'priority', tracker_constants.OPEN_ISSUES_CAN)
+
+    # If the user did a search or sort or all in a small can, show flipper.
+    self.VerifyShouldShowFlipper(
+        True, 'memory leak', '', tracker_constants.OPEN_ISSUES_CAN)
+    self.VerifyShouldShowFlipper(
+        True, 'id=1,2,3', '', tracker_constants.OPEN_ISSUES_CAN)
+    # Any can other than 1 or 2 is doing a query and so it should have a
+    # failry narrow result set size.  5 is issues starred by me.
+    self.VerifyShouldShowFlipper(True, '', '', 5)
+    self.VerifyShouldShowFlipper(
+        True, '', 'status', tracker_constants.OPEN_ISSUES_CAN)
+
+    # In a project without a huge number of issues, still show the flipper even
+    # if there was no specific query.
+    self.VerifyShouldShowFlipper(
+        True, '', '', tracker_constants.OPEN_ISSUES_CAN)
+
+  def testShouldShowFlipper_LargeSizedProject(self):
+    settings.threshold_to_suppress_prev_next = 1
+
+    # In a project that has tons of issues, save time by not showing the
+    # flipper unless there was a specific query, sort, or can.
+    self.VerifyShouldShowFlipper(
+        False, '', '', tracker_constants.ALL_ISSUES_CAN, create_issues=3)
+    self.VerifyShouldShowFlipper(
+        False, '', '', tracker_constants.OPEN_ISSUES_CAN, create_issues=3)