Add test for ash devtools DOM agent getDocument method

ash/common/devtools/ash_devtools_unittest.cc

+// 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.
+
+#include "ash/common/devtools/ash_devtools_dom_agent.h"
+
+#include "ash/common/test/ash_test.h"
+#include "ash/common/wm_lookup.h"
+#include "ash/common/wm_shell.h"
+#include "ash/common/wm_window.h"
+#include "ui/views/widget/widget.h"
+
+namespace ash {
+namespace {
+using namespace ui::devtools::protocol;
+const int kDefaultChildNodeCount = -1;
+
+class TestView : public views::View {
+ public:
+  TestView(const char* name) : views::View(), name_(name) {}
+
+  const char* GetClassName() const override { return name_; }
+
+ private:
+  const char* name_;
+
+  DISALLOW_COPY_AND_ASSIGN(TestView);
+};
+
+std::string GetAttributeValue(const std::string& attribute, DOM::Node* node) {
+  EXPECT_TRUE(node->hasAttributes());
+  Array<std::string>* attributes = node->getAttributes(nullptr);
+  for (size_t i = 0; i < attributes->length() - 1; i++) {
+    if (attributes->get(i) == attribute) {

[sadrul, 2016/11/02 15:23:05]

Don't need {}

[Sarmad Hashmi, 2016/11/02 16:32:34]

Done.

+      return attributes->get(i + 1);
+    }
+  }
+  return nullptr;
+}
+
+bool Equals(views::Widget* widget, DOM::Node* node) {
+  return "Widget" == node->getNodeName() &&
+         widget->GetName() == GetAttributeValue("name", node) &&
+         (widget->GetRootView() ? 1 : 0) ==
+             node->getChildNodeCount(kDefaultChildNodeCount);
+}
+
+bool Equals(WmWindow* window, DOM::Node* node) {
+  return "Window" == node->getNodeName() &&
+         window->GetName() == GetAttributeValue("name", node) &&
+         static_cast<int>(window->GetChildren().size()) ==
+             node->getChildNodeCount(kDefaultChildNodeCount);
+}
+
+void Compare(views::View* view, DOM::Node* node) {
+  EXPECT_EQ("View", node->getNodeName());
+  EXPECT_EQ(view->GetClassName(), GetAttributeValue("name", node));
+  EXPECT_EQ(view->child_count(),
+            node->getChildNodeCount(kDefaultChildNodeCount));
+}
+
+void Compare(WmWindow* window, DOM::Node* node) {
+  EXPECT_TRUE(Equals(window, node));
+}
+
+DOM::Node* FindInRoot(WmWindow* window, DOM::Node* root) {
+  if (Equals(window, root))
+    return root;
+
+  Array<DOM::Node>* children = root->getChildren(nullptr);
+  DOM::Node* window_node = nullptr;
+  for (size_t i = 0; i < children->length(); i++) {
+    window_node = FindInRoot(window, children->get(i));
+    if (window_node)
+      return window_node;
+  }
+  return window_node;
+}
+
+DOM::Node* FindInRoot(views::Widget* widget, DOM::Node* root) {
+  if (Equals(widget, root))
+    return root;
+
+  Array<DOM::Node>* children = root->getChildren(nullptr);
+  DOM::Node* widget_node = nullptr;
+  for (size_t i = 0; i < children->length(); i++) {
+    widget_node = FindInRoot(widget, children->get(i));
+    if (widget_node)
+      return widget_node;
+  }
+  return widget_node;
+}
+
+}  // namespace
+
+class AshDevToolsTest : public AshTest {
+ public:
+  AshDevToolsTest() {}
+  ~AshDevToolsTest() override {}
+
+  void SetUp() override {
+    AshTest::SetUp();
+    dom_agent_ =
+        base::MakeUnique<devtools::AshDevToolsDOMAgent>(WmShell::Get());
+  }
+
+  void TearDown() override {
+    dom_agent_.reset();
+    AshTest::TearDown();
+  }
+
+  devtools::AshDevToolsDOMAgent* dom_agent() { return dom_agent_.get(); }
+
+ private:
+  std::unique_ptr<devtools::AshDevToolsDOMAgent> dom_agent_;
+
+  DISALLOW_COPY_AND_ASSIGN(AshDevToolsTest);
+};
+
+TEST_F(AshDevToolsTest, GetDocumentWithWindowWidgetView) {
+  std::unique_ptr<views::Widget> widget(
+      CreateTestWidget(gfx::Rect(1, 1, 1, 1)));
+  WmWindow* parent_window = WmLookup::Get()->GetWindowForWidget(widget.get());
+  parent_window->SetName("parent_window");
+  std::unique_ptr<WindowOwner> child_owner(CreateChildWindow(parent_window));
+  WmWindow* child_window = child_owner->window();
+  child_window->SetName("child_window");
+  widget->Show();
+  views::View* child_view = new TestView("child_view");
+  widget->GetRootView()->AddChildView(child_view);
+
+  std::unique_ptr<ui::devtools::protocol::DOM::Node> root;
+  dom_agent()->getDocument(nullptr, &root);

[sadrul, 2016/11/02 15:23:05]

use some variable for the nullptr error string, e.g.

  const ErrorString* kNullError = nullptr;
  dom_agent()->getDocument(kNullError, &root);

ditto for getChildren() calls below.

[Sarmad Hashmi, 2016/11/02 16:32:34]

Done.

+  DOM::Node* parent_node = FindInRoot(parent_window, root.get());
+  DOM::Node* widget_node = FindInRoot(widget.get(), root.get());
+
+  EXPECT_TRUE(parent_node);
+  EXPECT_TRUE(widget_node);
+  Compare(child_window, parent_node->getChildren(nullptr)->get(0));

[sadrul, 2016/11/02 15:23:05]

First ASSERT() that parent_node->getChildren(nullptr)) is non-null (because if
it is null, then it will cause a crash, whereas ASSERT() would fail the test,
and abort the test, i.e. it will not run the code below, thus avoiding the
crash)

[Sarmad Hashmi, 2016/11/02 16:32:34]

Done.

+  Compare(widget->GetRootView(), widget_node->getChildren(nullptr)->get(0));
+  Compare(
+      child_view,
+      widget_node->getChildren(nullptr)->get(0)->getChildren(nullptr)->get(1));
+}
+
+}  // namespace ash