[Autofill Assistant] Handle value field in FormValueMatch.

Bug: b/119554665

Change-Id: I9087ab89ff72f083d9fc97512a539026551e4fb4
Reviewed-on: https://chromium-review.googlesource.com/c/1365441
Commit-Queue: Jordan Demeulenaere <jdemeulenaere@chromium.org>
Reviewed-by: Stephane Zermatten <szermatt@chromium.org>
Cr-Commit-Position: refs/heads/master@{#614670}

components/autofill_assistant/browser/script_precondition.cc

@@ -100,12 +100,13 @@ void ScriptPrecondition::Check(
     batch_checks->AddElementCheck(kExistenceCheck, selector,
                                   std::move(callback));
   }
-  for (const auto& value_match : form_value_match_) {
+  for (size_t i = 0; i < form_value_match_.size(); i++) {
+    const auto& value_match = form_value_match_[i];
     DCHECK(!value_match.element().selectors().empty());
     batch_checks->AddFieldValueCheck(
         Selector(value_match.element()),
         base::BindOnce(&ScriptPrecondition::OnGetFieldValue,
-                       weak_ptr_factory_.GetWeakPtr()));
+                       weak_ptr_factory_.GetWeakPtr(), i));
   }
 }
 
@@ -200,8 +201,21 @@ void ScriptPrecondition::OnCheckElementExists(bool exists) {
   ReportCheckResult(exists);
 }
 
-void ScriptPrecondition::OnGetFieldValue(bool exists,
+void ScriptPrecondition::OnGetFieldValue(int index,
+                                         bool exists,
                                          const std::string& value) {
+  if (!exists) {
+    ReportCheckResult(false);
+    return;
+  }
+
+  // TODO(crbug.com/806868): Differentiate between empty value and failure.
+  const auto& value_match = form_value_match_[index];
+  if (value_match.has_value()) {
+    ReportCheckResult(value == value_match.value());
+    return;
+  }
+
   ReportCheckResult(!value.empty());
 }
 

components/autofill_assistant/browser/script_precondition.h

@@ -65,7 +65,7 @@ class ScriptPrecondition {
       const std::map<std::string, ScriptStatusProto>& executed_scripts) const;
 
   void OnCheckElementExists(bool exists);
-  void OnGetFieldValue(bool exists, const std::string& value);
+  void OnGetFieldValue(int index, bool exists, const std::string& value);
   void ReportCheckResult(bool success);
 
   std::vector<Selector> elements_exist_;

components/autofill_assistant/browser/script_precondition_unittest.cc

@@ -322,6 +322,13 @@ TEST_F(ScriptPreconditionTest, FormValueMatch) {
   match->mutable_element()->add_selectors("exists");
   EXPECT_TRUE(Check(proto));
 
+  match->set_value("bar");
+  EXPECT_FALSE(Check(proto));
+
+  match->set_value("foo");
+  EXPECT_TRUE(Check(proto));
+
+  match->clear_value();
   match->mutable_element()->set_selectors(0, "does_not_exist");
   EXPECT_FALSE(Check(proto));
 }

components/autofill_assistant/browser/service.proto

@@ -156,6 +156,11 @@ message FormValueMatchProto {
   // Required. The selector associated to the form element whose value should be
   // checked.
   optional ElementReferenceProto element = 1;
+
+  // Optional value. If specified, the element value must match the given value,
+  // even if it's empty. If not specified, we just check that the element value
+  // is non empty.
+  optional string value = 2;
 }
 
 enum PolicyType {