diff --git a/services/test/tracker_fulltext_test.py b/services/test/tracker_fulltext_test.py
new file mode 100644
index 0000000..db8a7a7
--- /dev/null
+++ b/services/test/tracker_fulltext_test.py
@@ -0,0 +1,283 @@
+# 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 tracker_fulltext module."""
+from __future__ import print_function
+from __future__ import division
+from __future__ import absolute_import
+
+import unittest
+
+import mox
+
+from google.appengine.api import search
+
+import settings
+from framework import framework_views
+from proto import ast_pb2
+from proto import tracker_pb2
+from services import fulltext_helpers
+from services import tracker_fulltext
+from testing import fake
+from tracker import tracker_bizobj
+
+
+class TrackerFulltextTest(unittest.TestCase):
+
+  def setUp(self):
+    self.mox = mox.Mox()
+    self.mock_index = self.mox.CreateMockAnything()
+    self.mox.StubOutWithMock(search, 'Index')
+    self.docs = None
+    self.cnxn = 'fake connection'
+    self.user_service = fake.UserService()
+    self.user_service.TestAddUser('test@example.com', 111)
+    self.issue_service = fake.IssueService()
+    self.config_service = fake.ConfigService()
+
+    self.issue = fake.MakeTestIssue(
+        123, 1, 'test summary', 'New', 111)
+    self.issue_service.TestAddIssue(self.issue)
+    self.comment = tracker_pb2.IssueComment(
+        project_id=789, issue_id=self.issue.issue_id, user_id=111,
+        content='comment content',
+        attachments=[
+            tracker_pb2.Attachment(filename='hello.c'),
+            tracker_pb2.Attachment(filename='hello.h')])
+    self.issue_service.TestAddComment(self.comment, 1)
+    self.users_by_id = framework_views.MakeAllUserViews(
+        self.cnxn, self.user_service, [111])
+
+  def tearDown(self):
+    self.mox.UnsetStubs()
+    self.mox.ResetAll()
+
+  def RecordDocs(self, docs):
+    self.docs = docs
+
+  def SetUpIndexIssues(self):
+    search.Index(name=settings.search_index_name_format % 1).AndReturn(
+        self.mock_index)
+    self.mock_index.put(mox.IgnoreArg()).WithSideEffects(self.RecordDocs)
+
+  def testIndexIssues(self):
+    self.SetUpIndexIssues()
+    self.mox.ReplayAll()
+    tracker_fulltext.IndexIssues(
+        self.cnxn, [self.issue], self.user_service, self.issue_service,
+        self.config_service)
+    self.mox.VerifyAll()
+    self.assertEqual(1, len(self.docs))
+    issue_doc = self.docs[0]
+    self.assertEqual(123, issue_doc.fields[0].value)
+    self.assertEqual('test summary', issue_doc.fields[1].value)
+
+  def SetUpCreateIssueSearchDocuments(self):
+    self.mox.StubOutWithMock(tracker_fulltext, '_IndexDocsInShard')
+    tracker_fulltext._IndexDocsInShard(1, mox.IgnoreArg()).WithSideEffects(
+        lambda shard_id, docs: self.RecordDocs(docs))
+
+  def testCreateIssueSearchDocuments_Normal(self):
+    self.SetUpCreateIssueSearchDocuments()
+    self.mox.ReplayAll()
+    config_dict = {123: tracker_bizobj.MakeDefaultProjectIssueConfig(123)}
+    tracker_fulltext._CreateIssueSearchDocuments(
+        [self.issue], {self.issue.issue_id: [self.comment]}, self.users_by_id,
+        config_dict)
+    self.mox.VerifyAll()
+    self.assertEqual(1, len(self.docs))
+    issue_doc = self.docs[0]
+    self.assertEqual(5, len(issue_doc.fields))
+    self.assertEqual(123, issue_doc.fields[0].value)
+    self.assertEqual('test summary', issue_doc.fields[1].value)
+    self.assertEqual('test@example.com comment content hello.c hello.h',
+                     issue_doc.fields[3].value)
+    self.assertEqual('', issue_doc.fields[4].value)
+
+  def testCreateIssueSearchDocuments_NoIndexableComments(self):
+    """Sometimes all comments on a issue are spam or deleted."""
+    self.SetUpCreateIssueSearchDocuments()
+    self.mox.ReplayAll()
+    config_dict = {123: tracker_bizobj.MakeDefaultProjectIssueConfig(123)}
+    self.comment.deleted_by = 111
+    tracker_fulltext._CreateIssueSearchDocuments(
+        [self.issue], {self.issue.issue_id: [self.comment]}, self.users_by_id,
+        config_dict)
+    self.mox.VerifyAll()
+    self.assertEqual(1, len(self.docs))
+    issue_doc = self.docs[0]
+    self.assertEqual(5, len(issue_doc.fields))
+    self.assertEqual(123, issue_doc.fields[0].value)
+    self.assertEqual('test summary', issue_doc.fields[1].value)
+    self.assertEqual('', issue_doc.fields[3].value)
+    self.assertEqual('', issue_doc.fields[4].value)
+
+  def testCreateIssueSearchDocuments_CustomFields(self):
+    self.SetUpCreateIssueSearchDocuments()
+    self.mox.ReplayAll()
+    config = tracker_bizobj.MakeDefaultProjectIssueConfig(123)
+    config_dict = {123: tracker_bizobj.MakeDefaultProjectIssueConfig(123)}
+    int_field = tracker_bizobj.MakeFieldDef(
+        1, 123, 'CustomInt', tracker_pb2.FieldTypes.INT_TYPE, None, False,
+        False, False, None, None, None, None, False, None, None, None,
+        'no_action', 'A custom int field', False)
+    int_field_value = tracker_bizobj.MakeFieldValue(
+        1, 42, None, None, False, None, None)
+    str_field = tracker_bizobj.MakeFieldDef(
+        2, 123, 'CustomStr', tracker_pb2.FieldTypes.STR_TYPE, None, False,
+        False, False, None, None, None, None, False, None, None, None,
+        'no_action', 'A custom string field', False)
+    str_field_value = tracker_bizobj.MakeFieldValue(
+        2, None, u'\xf0\x9f\x92\x96\xef\xb8\x8f', None, None, None, False)
+    # TODO(jrobbins): user-type field 3
+    date_field = tracker_bizobj.MakeFieldDef(
+        4, 123, 'CustomDate', tracker_pb2.FieldTypes.DATE_TYPE, None, False,
+        False, False, None, None, None, None, False, None, None, None,
+        'no_action', 'A custom date field', False)
+    date_field_value = tracker_bizobj.MakeFieldValue(
+        4, None, None, None, 1234567890, None, False)
+    config.field_defs.extend([int_field, str_field, date_field])
+    self.issue.field_values.extend([
+        int_field_value, str_field_value, date_field_value])
+
+    tracker_fulltext._CreateIssueSearchDocuments(
+        [self.issue], {self.issue.issue_id: [self.comment]}, self.users_by_id,
+        config_dict)
+    self.mox.VerifyAll()
+    self.assertEqual(1, len(self.docs))
+    issue_doc = self.docs[0]
+    metadata = issue_doc.fields[2]
+    self.assertEqual(
+      u'New test@example.com []  42 \xf0\x9f\x92\x96\xef\xb8\x8f 2009-02-13 ',
+      metadata.value)
+
+  def testExtractCommentText(self):
+    extracted_text = tracker_fulltext._ExtractCommentText(
+        self.comment, self.users_by_id)
+    self.assertEqual(
+        'test@example.com comment content hello.c hello.h',
+        extracted_text)
+
+  def testIndexableComments_NumberOfComments(self):
+    """We consider at most 100 initial comments and 500 most recent comments."""
+    comments = [self.comment]
+    indexable = tracker_fulltext._IndexableComments(comments, self.users_by_id)
+    self.assertEqual(1, len(indexable))
+
+    comments = [self.comment] * 100
+    indexable = tracker_fulltext._IndexableComments(comments, self.users_by_id)
+    self.assertEqual(100, len(indexable))
+
+    comments = [self.comment] * 101
+    indexable = tracker_fulltext._IndexableComments(comments, self.users_by_id)
+    self.assertEqual(101, len(indexable))
+
+    comments = [self.comment] * 600
+    indexable = tracker_fulltext._IndexableComments(comments, self.users_by_id)
+    self.assertEqual(600, len(indexable))
+
+    comments = [self.comment] * 601
+    indexable = tracker_fulltext._IndexableComments(comments, self.users_by_id)
+    self.assertEqual(600, len(indexable))
+    self.assertNotIn(100, indexable)
+
+  def testIndexableComments_NumberOfChars(self):
+    """We consider comments that can fit into the search index document."""
+    self.comment.content = 'x' * 1000
+    comments = [self.comment] * 100
+
+    indexable = tracker_fulltext._IndexableComments(
+        comments, self.users_by_id, remaining_chars=100000)
+    self.assertEqual(100, len(indexable))
+
+    indexable = tracker_fulltext._IndexableComments(
+        comments, self.users_by_id, remaining_chars=50000)
+    self.assertEqual(50, len(indexable))
+    indexable = tracker_fulltext._IndexableComments(
+        comments, self.users_by_id, remaining_chars=50999)
+    self.assertEqual(50, len(indexable))
+
+    indexable = tracker_fulltext._IndexableComments(
+        comments, self.users_by_id, remaining_chars=999)
+    self.assertEqual(0, len(indexable))
+
+    indexable = tracker_fulltext._IndexableComments(
+      comments, self.users_by_id, remaining_chars=0)
+    self.assertEqual(0, len(indexable))
+
+    indexable = tracker_fulltext._IndexableComments(
+      comments, self.users_by_id, remaining_chars=-1)
+    self.assertEqual(0, len(indexable))
+
+  def SetUpUnindexIssues(self):
+    search.Index(name=settings.search_index_name_format % 1).AndReturn(
+        self.mock_index)
+    self.mock_index.delete(['1'])
+
+  def testUnindexIssues(self):
+    self.SetUpUnindexIssues()
+    self.mox.ReplayAll()
+    tracker_fulltext.UnindexIssues([1])
+    self.mox.VerifyAll()
+
+  def SetUpSearchIssueFullText(self):
+    self.mox.StubOutWithMock(fulltext_helpers, 'ComprehensiveSearch')
+    fulltext_helpers.ComprehensiveSearch(
+        '(project_id:789) (summary:"test")',
+        settings.search_index_name_format % 1).AndReturn([123, 234])
+
+  def testSearchIssueFullText_Normal(self):
+    self.SetUpSearchIssueFullText()
+    self.mox.ReplayAll()
+    summary_fd = tracker_pb2.FieldDef(
+        field_name='summary', field_type=tracker_pb2.FieldTypes.STR_TYPE)
+    query_ast_conj = ast_pb2.Conjunction(conds=[
+        ast_pb2.Condition(
+            op=ast_pb2.QueryOp.TEXT_HAS, field_defs=[summary_fd],
+            str_values=['test'])])
+    issue_ids, capped = tracker_fulltext.SearchIssueFullText(
+        [789], query_ast_conj, 1)
+    self.mox.VerifyAll()
+    self.assertItemsEqual([123, 234], issue_ids)
+    self.assertFalse(capped)
+
+  def testSearchIssueFullText_CrossProject(self):
+    self.mox.StubOutWithMock(fulltext_helpers, 'ComprehensiveSearch')
+    fulltext_helpers.ComprehensiveSearch(
+        '(project_id:789 OR project_id:678) (summary:"test")',
+        settings.search_index_name_format % 1).AndReturn([123, 234])
+    self.mox.ReplayAll()
+
+    summary_fd = tracker_pb2.FieldDef(
+        field_name='summary', field_type=tracker_pb2.FieldTypes.STR_TYPE)
+    query_ast_conj = ast_pb2.Conjunction(conds=[
+        ast_pb2.Condition(
+            op=ast_pb2.QueryOp.TEXT_HAS, field_defs=[summary_fd],
+            str_values=['test'])])
+    issue_ids, capped = tracker_fulltext.SearchIssueFullText(
+        [789, 678], query_ast_conj, 1)
+    self.mox.VerifyAll()
+    self.assertItemsEqual([123, 234], issue_ids)
+    self.assertFalse(capped)
+
+  def testSearchIssueFullText_Capped(self):
+    try:
+      orig = settings.fulltext_limit_per_shard
+      settings.fulltext_limit_per_shard = 1
+      self.SetUpSearchIssueFullText()
+      self.mox.ReplayAll()
+      summary_fd = tracker_pb2.FieldDef(
+        field_name='summary', field_type=tracker_pb2.FieldTypes.STR_TYPE)
+      query_ast_conj = ast_pb2.Conjunction(conds=[
+          ast_pb2.Condition(
+              op=ast_pb2.QueryOp.TEXT_HAS, field_defs=[summary_fd],
+              str_values=['test'])])
+      issue_ids, capped = tracker_fulltext.SearchIssueFullText(
+          [789], query_ast_conj, 1)
+      self.mox.VerifyAll()
+      self.assertItemsEqual([123, 234], issue_ids)
+      self.assertTrue(capped)
+    finally:
+      settings.fulltext_limit_per_shard = orig