[Autofill/Autocomplete Feature] Substring matching instead of prefix matching.

components/autofill/core/browser/autofill_manager_unittest.cc

 // Copyright 2013 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.
 
 #include <algorithm>
 #include <vector>
 
 #include "base/command_line.h"
 #include "base/format_macros.h"
 #include "base/memory/ref_counted.h"
@@ skipping 3158 matching lines @@
   AutocompleteSuggestionsReturned(std::vector<base::string16>());
 
   external_delegate_->CheckSuggestions(
       kDefaultPageID,
       Suggestion(
           "Visa \xE2\x8B\xAF"
           "3456",
           "04/12", kVisaCard, autofill_manager_->GetPackedCreditCardID(4)));
 }
 
+// Test that suggestion tokens (substrings separated by characters from "
+// .,-_@") are matched against field contents.
+TEST_F(AutofillManagerTest, DisplaySuggestionsWithMatchingTokens) {
+  // Token matching is currently behind a flag.
+  base::CommandLine::ForCurrentProcess()->AppendSwitch(
+      autofill::switches::kEnableSuggestionsWithSubstringMatch);
+
+  // Set up our form data.
+  FormData form;
+  test::CreateTestAddressFormData(&form);
+  std::vector<FormData> forms(1, form);
+  FormsSeen(forms);
+
+  // Simulate displaying suggestions for field contents "gmail", check that
+  // matching ones are displayed.
+  FormFieldData field;
+  test::CreateTestFormField("Email", "email", "gmail", "email", &field);
+  GetAutofillSuggestions(form, field);
+  AutocompleteSuggestionsReturned(std::vector<base::string16>());
+
+  external_delegate_->CheckSuggestions(
+      kDefaultPageID,
+      Suggestion("theking@gmail.com", "Elvis Aaron Presley", "", 1),
+      Suggestion("buddy@gmail.com", "Charles Hardin Holley", "", 2));
+}
+
+// Test that suggestions which do not have a prefix match or prefix-token match
+// with the field contents are not matched.
+TEST_F(AutofillManagerTest, NoSuggestionForNonPrefixTokenMatch) {
+  // Token matching is currently behind a flag.
+  base::CommandLine::ForCurrentProcess()->AppendSwitch(
+      autofill::switches::kEnableSuggestionsWithSubstringMatch);
+
+  // Set up our form data.
+  FormData form;
+  test::CreateTestAddressFormData(&form);
+  std::vector<FormData> forms(1, form);
+  FormsSeen(forms);
+
+  // Simulate displaying suggestions for field contents "mail". Check that none
+  // appear, because none has a token with a prefix "mail".
+  FormFieldData field;
+  test::CreateTestFormField("Email", "email", "mail", "email", &field);
+  GetAutofillSuggestions(form, field);
+  EXPECT_FALSE(external_delegate_->on_suggestions_returned_seen());
+}
+
+// Test matching when field contents contains suggestion token separators.
+TEST_F(AutofillManagerTest, MatchingContentsWithSuggestionTokenSeparator) {
+  // Token matching is currently behind a flag.
+  base::CommandLine::ForCurrentProcess()->AppendSwitch(
+      autofill::switches::kEnableSuggestionsWithSubstringMatch);
+
+  // Set up our form data.
+  FormData form;
+  test::CreateTestAddressFormData(&form);
+  std::vector<FormData> forms(1, form);
+  FormsSeen(forms);
+
+  // Simulate displaying suggestions for field contents "buddy@gma", check that
+  // matching one is displayed. Please also note here that field contents
+  // contains token separators '@', |IsContentsPrefixOfSuggestionToken()| only
+  // picks suggestions that passes the constrain that |field_contents| prefix

[vabr (Chromium), 2015/03/31 09:38:07]

grammar:
passes -> pass (suggestions are plural)
prefix -> prefixes (|field_contents| is a single string)

[Pritam Nikam, 2015/03/31 14:26:11]

Done.

+  // some token in |field_suggestion|. In our test case, only "buddy@gmail.com"
+  // passes both the constrains and apparently we could see only that in

[vabr (Chromium), 2015/03/31 09:38:07]

The comment confuses me. It says "both the constraints", and only one is
mentioned above: "|field_contents| prefix some token in |field_suggestion|". The
mentioned constraint is moreover not satisfied by "buddy@gma", as it spans
multiple tokens. Please check the comment, and if possible, try to simplify it.

[Pritam Nikam, 2015/03/31 14:26:11]

I've corrected this and chosen "gmail.co" as field contents.
With "buddy@gma" as field contents and StartsWith() still in place "buddy@gma"
will still brings up buddy@gmail.com" in suggestions.

+  // matching suggestion list.
+  FormFieldData field;
+  test::CreateTestFormField("Email", "email", "buddy@gma", "email", &field);
+  GetAutofillSuggestions(form, field);
+  AutocompleteSuggestionsReturned(std::vector<base::string16>());
+
+  external_delegate_->CheckSuggestions(
+      kDefaultPageID,
+      Suggestion("buddy@gmail.com", "Charles Hardin Holley", "", 1));
+}
+
 }  // namespace autofill