[Autofill Assistant] Make scripts without preconditions runnable.

With this change, scripts without precondition are not treated as
invalid, but runnable. Also includes a small test
ProtocolUtils::ParseScripts.

Bug: 806868
Change-Id: I6c286b1622bfeb4d635310396cb3b158ffd6933e
Reviewed-on: https://chromium-review.googlesource.com/1219748Reviewed-by: Ganggui Tang <gogerald@chromium.org>
Commit-Queue: Stephane Zermatten <szermatt@chromium.org>
Cr-Commit-Position: refs/heads/master@{#590333}

components/autofill_assistant/browser/BUILD.gn

@@ -72,6 +72,7 @@ source_set("unit_tests") {
     "mock_ui_controller.h",
     "mock_web_controller.cc",
     "mock_web_controller.h",
+    "protocol_utils_unittest.cc",
     "script_executor_unittest.cc",
     "script_precondition_unittest.cc",
     "script_tracker_unittest.cc",

components/autofill_assistant/browser/protocol_utils.cc

@@ -51,11 +51,8 @@ bool ProtocolUtils::ParseScripts(
 
     const auto& presentation = script_proto.presentation();
     script->handle.name = presentation.name();
-
-    if (presentation.has_precondition()) {
     script->precondition =
         ScriptPrecondition::FromProto(presentation.precondition());
-    }
 
     if (script->handle.name.empty() || script->handle.path.empty() ||
         !script->precondition) {

components/autofill_assistant/browser/protocol_utils_unittest.cc

+// Copyright 2018 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 "components/autofill_assistant/browser/protocol_utils.h"
+
+#include "base/macros.h"
+#include "components/autofill_assistant/browser/service.pb.h"
+#include "testing/gmock/include/gmock/gmock.h"
+
+namespace autofill_assistant {
+namespace {
+
+using ::testing::SizeIs;
+using ::testing::IsEmpty;
+
+TEST(ProtocolUtilsTest, NoScripts) {
+  std::vector<std::unique_ptr<Script>> scripts;
+  EXPECT_TRUE(ProtocolUtils::ParseScripts("", &scripts));
+  EXPECT_THAT(scripts, IsEmpty());
+}
+
+TEST(ProtocolUtilsTest, SomeInvalidScripts) {
+  SupportsScriptResponseProto proto;
+
+  // 2 Invalid scripts, 1 valid one, with no preconditions.
+  proto.add_scripts()->mutable_presentation()->set_name("missing path");
+  proto.add_scripts()->set_path("missing name");
+  SupportedScriptProto* script = proto.add_scripts();
+  script->set_path("ok");
+  script->mutable_presentation()->set_name("ok name");
+
+  // Only the valid script is returned.
+  std::vector<std::unique_ptr<Script>> scripts;
+  std::string proto_str;
+  proto.SerializeToString(&proto_str);
+  EXPECT_TRUE(ProtocolUtils::ParseScripts(proto_str, &scripts));
+  ASSERT_THAT(scripts, SizeIs(1));
+  EXPECT_EQ("ok", scripts[0]->handle.path);
+  EXPECT_EQ("ok name", scripts[0]->handle.name);
+  EXPECT_NE(nullptr, scripts[0]->precondition);
+}
+
+}  // namespace
+}  // namespace autofill_assistant

components/autofill_assistant/browser/service.proto

@@ -27,7 +27,7 @@ message SupportsScriptResponseProto {
 // Supported script.
 message SupportedScriptProto {
   // This is the internal name of the script.
-  required string path = 1;
+  optional string path = 1;
 
   message PresentationProto {
     // Script name.