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

components/autofill/core/browser/autofill_manager_unittest.cc

Index: components/autofill/core/browser/autofill_manager_unittest.cc
diff --git a/components/autofill/core/browser/autofill_manager_unittest.cc b/components/autofill/core/browser/autofill_manager_unittest.cc
index cf418342df54c7b545d9c75121d4631859f11ffa..ff25129e7f8e4d2dc3ccc407ca348db3bc72436b 100644
--- a/components/autofill/core/browser/autofill_manager_unittest.cc
+++ b/components/autofill/core/browser/autofill_manager_unittest.cc
@@ -3176,4 +3176,91 @@ TEST_F(AutofillManagerTest, GetCreditCardSuggestionsForNumberSpitAcrossFields) {
           "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 "gmail.co", Check that
+  // none appear, because none has a token with a prefix "gmail.co". Please also
+  // note here that field contents contains token separator '.',
+  // |IsContentsPrefixOfSuggestionToken()| only picks suggestions that pass the
+  // constrain that |field_contents| prefixes some token in |field_suggestion|.
+  // Field contents "gmal.co" rather spans multiple tokens. In our test case,
+  // none of the suggestions pass this constrain and apparently we could see
+  // none in matching suggestion list.
+  FormFieldData field;
+  test::CreateTestFormField("Email", "email", "gmail.co", "email", &field);
+  GetAutofillSuggestions(form, field);
+  EXPECT_FALSE(external_delegate_->on_suggestions_returned_seen());
+
+  // Simulate displaying suggestions for field contents "buddy@gm", check that
+  // matching one is displayed. Please note here that field contents "buddy@gm"
+  // spans to multiple tokens and none of the suggestions pass
+  // |IsContentsPrefixOfSuggestionToken()|'s constrain.  However; unlike our
+  // previous test; the field contents whole-text prefixes the "buddy@gmail.com"
+  // suggestion and we could see it in suggestion  list.
+  test::CreateTestFormField("Email", "email", "buddy@gm", "email", &field);
+  GetAutofillSuggestions(form, field);
+  AutocompleteSuggestionsReturned(std::vector<base::string16>());
+
+  external_delegate_->CheckSuggestions(
+      kDefaultPageID,
+      Suggestion("buddy@gmail.com", "Charles Hardin Holley", "", 1));
+}
+
 }  // namespace autofill