diff --git a/tracker/test/issueattachmenttext_test.py b/tracker/test/issueattachmenttext_test.py
new file mode 100644
index 0000000..187aa42
--- /dev/null
+++ b/tracker/test/issueattachmenttext_test.py
@@ -0,0 +1,191 @@
+# 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 issueattachmenttext."""
+from __future__ import print_function
+from __future__ import division
+from __future__ import absolute_import
+
+import logging
+import unittest
+from mock import patch
+
+from google.appengine.ext import testbed
+
+from third_party import cloudstorage
+import ezt
+
+import webapp2
+
+from framework import filecontent
+from framework import permissions
+from proto import tracker_pb2
+from services import service_manager
+from testing import fake
+from testing import testing_helpers
+from tracker import issueattachmenttext
+
+
+class IssueAttachmentTextTest(unittest.TestCase):
+
+  def setUp(self):
+    self.testbed = testbed.Testbed()
+    self.testbed.activate()
+    self.testbed.init_app_identity_stub()
+
+    services = service_manager.Services(
+        project=fake.ProjectService(),
+        config=fake.ConfigService(),
+        issue=fake.IssueService(),
+        user=fake.UserService())
+    self.project = services.project.TestAddProject('proj')
+    self.servlet = issueattachmenttext.AttachmentText(
+        'req', 'res', services=services)
+
+    services.user.TestAddUser('commenter@example.com', 111)
+
+    self.issue = tracker_pb2.Issue()
+    self.issue.local_id = 1
+    self.issue.issue_id = 1
+    self.issue.summary = 'sum'
+    self.issue.project_name = 'proj'
+    self.issue.project_id = self.project.project_id
+    services.issue.TestAddIssue(self.issue)
+
+    self.comment0 = tracker_pb2.IssueComment()
+    self.comment0.content = 'this is the description'
+    self.comment0.user_id = 111
+    self.comment1 = tracker_pb2.IssueComment()
+    self.comment1.content = 'this is a comment'
+    self.comment1.user_id = 111
+
+    self.attach0 = tracker_pb2.Attachment(
+        attachment_id=4567, filename='b.txt', mimetype='text/plain',
+        gcs_object_id='/pid/attachments/abcd')
+    self.comment0.attachments.append(self.attach0)
+
+    self.attach1 = tracker_pb2.Attachment(
+        attachment_id=1234, filename='a.txt', mimetype='text/plain',
+        gcs_object_id='/pid/attachments/abcdefg')
+    self.comment0.attachments.append(self.attach1)
+
+    self.bin_attach = tracker_pb2.Attachment(
+        attachment_id=2468, mimetype='application/octets',
+        gcs_object_id='/pid/attachments/\0\0\0\0\0\1\2\3')
+    self.comment1.attachments.append(self.bin_attach)
+
+    self.comment0.project_id = self.project.project_id
+    services.issue.TestAddComment(self.comment0, self.issue.local_id)
+    self.comment1.project_id = self.project.project_id
+    services.issue.TestAddComment(self.comment1, self.issue.local_id)
+    services.issue.TestAddAttachment(
+        self.attach0, self.comment0.id, self.issue.issue_id)
+    services.issue.TestAddAttachment(
+        self.attach1, self.comment1.id, self.issue.issue_id)
+    # TODO(jrobbins): add tests for binary content
+    self._old_gcs_open = cloudstorage.open
+    cloudstorage.open = fake.gcs_open
+
+  def tearDown(self):
+    self.testbed.deactivate()
+    cloudstorage.open = self._old_gcs_open
+
+  def testGatherPageData_CommentDeleted(self):
+    """If the attachment's comment was deleted, give a 403."""
+    _request, mr = testing_helpers.GetRequestObjects(
+        project=self.project,
+        path='/a/d.com/p/proj/issues/attachmentText?aid=1234',
+        perms=permissions.READ_ONLY_PERMISSIONSET)
+    self.servlet.GatherPageData(mr)  # OK
+    self.comment1.deleted_by = 111
+    self.assertRaises(  # 403
+        permissions.PermissionException,
+        self.servlet.GatherPageData, mr)
+
+  def testGatherPageData_IssueNotViewable(self):
+    """If the attachment's issue is not viewable, give a 403."""
+    _request, mr = testing_helpers.GetRequestObjects(
+        project=self.project,
+        path='/p/proj/issues/attachment?aid=1234',
+        perms=permissions.EMPTY_PERMISSIONSET)  # No VIEW
+    self.assertRaises(
+        permissions.PermissionException,
+        self.servlet.GatherPageData, mr)
+
+  def testGatherPageData_IssueDeleted(self):
+    _request, mr = testing_helpers.GetRequestObjects(
+        project=self.project,
+        path='/p/proj/issues/attachment?aid=1234',
+        perms=permissions.READ_ONLY_PERMISSIONSET)
+    self.issue.deleted = True
+    self.assertRaises(  # Issue was deleted
+        permissions.PermissionException,
+        self.servlet.GatherPageData, mr)
+
+  def testGatherPageData_IssueRestricted(self):
+    _request, mr = testing_helpers.GetRequestObjects(
+        project=self.project,
+        path='/p/proj/issues/attachment?aid=1234',
+        perms=permissions.READ_ONLY_PERMISSIONSET)
+    self.issue.labels.append('Restrict-View-Nobody')
+    self.assertRaises(  # Issue is restricted
+        permissions.PermissionException,
+        self.servlet.GatherPageData, mr)
+
+  def testGatherPageData_NoSuchAttachment(self):
+    _request, mr = testing_helpers.GetRequestObjects(
+        project=self.project,
+        path='/p/proj/issues/attachmentText?aid=9999',
+        perms=permissions.READ_ONLY_PERMISSIONSET)
+    with self.assertRaises(webapp2.HTTPException) as cm:
+      self.servlet.GatherPageData(mr)
+    self.assertEqual(404, cm.exception.code)
+
+  def testGatherPageData_AttachmentDeleted(self):
+    """If the attachment was deleted, give a 404."""
+    _request, mr = testing_helpers.GetRequestObjects(
+        project=self.project,
+        path='/p/proj/issues/attachmentText?aid=1234',
+        perms=permissions.READ_ONLY_PERMISSIONSET)
+    self.attach1.deleted = True
+    with self.assertRaises(webapp2.HTTPException) as cm:
+      self.servlet.GatherPageData(mr)
+    self.assertEqual(404, cm.exception.code)
+
+  def testGatherPageData_Normal(self):
+    _request, mr = testing_helpers.GetRequestObjects(
+        project=self.project,
+        path='/p/proj/issues/attachmentText?id=1&aid=1234',
+        perms=permissions.READ_ONLY_PERMISSIONSET)
+    page_data = self.servlet.GatherPageData(mr)
+    self.assertEqual(1, page_data['local_id'])
+    self.assertEqual('a.txt', page_data['filename'])
+    self.assertEqual('43 bytes', page_data['filesize'])
+    self.assertEqual(ezt.boolean(False), page_data['should_prettify'])
+    self.assertEqual(ezt.boolean(False), page_data['is_binary'])
+    self.assertEqual(ezt.boolean(False), page_data['too_large'])
+
+    file_lines = page_data['file_lines']
+    self.assertEqual(1, len(file_lines))
+    self.assertEqual(1, file_lines[0].num)
+    self.assertEqual('/app_default_bucket/pid/attachments/abcdefg',
+                     file_lines[0].line)
+
+    self.assertEqual(None, page_data['code_reviews'])
+
+  @patch('framework.filecontent.DecodeFileContents')
+  def testGatherPageData_HugeFile(self, mock_DecodeFileContents):
+    _request, mr = testing_helpers.GetRequestObjects(
+        project=self.project,
+        path='/p/proj/issues/attachmentText?id=1&aid=1234',
+        perms=permissions.READ_ONLY_PERMISSIONSET)
+    mock_DecodeFileContents.return_value = (
+        'too large text', False, True)
+
+    page_data = self.servlet.GatherPageData(mr)
+
+    self.assertEqual(ezt.boolean(False), page_data['should_prettify'])
+    self.assertEqual(ezt.boolean(False), page_data['is_binary'])
+    self.assertEqual(ezt.boolean(True), page_data['too_large'])