Add unit tests for chrome_pdf::NormalizeMouseEvent()

Add tests to make sure the function works as intended. Update
MouseEventBuilder::Build() to handle middle click events to support the
new test cases.

Change-Id: I24f108dd407be111b6228fa89d0b7e41bf70a046
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5528796
Commit-Queue: Lei Zhang <thestig@chromium.org>
Reviewed-by: Andy Phan <andyphan@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1299639}

pdf/BUILD.gn

@@ -350,6 +350,7 @@ if (enable_pdf) {
     sources = [
       "document_layout_unittest.cc",
       "draw_utils/coordinates_unittest.cc",
+      "input_utils_unittest.cc",
       "page_orientation_unittest.cc",
       "paint_manager_unittest.cc",
       "parsed_params_unittest.cc",

pdf/input_utils_unittest.cc

@@ -0,0 +1,104 @@
+// Copyright 2024 The Chromium Authors
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "pdf/input_utils.h"
+
+#include "build/build_config.h"
+#include "pdf/test/mouse_event_builder.h"
+#include "testing/gtest/include/gtest/gtest.h"
+#include "third_party/blink/public/common/input/web_input_event.h"
+#include "third_party/blink/public/common/input/web_mouse_event.h"
+#include "third_party/blink/public/common/input/web_pointer_properties.h"
+
+namespace chrome_pdf {
+
+namespace {
+
+void CheckNormalizeMouseEventIsNoOp(const blink::WebMouseEvent& event) {
+  blink::WebMouseEvent normalized_event = NormalizeMouseEvent(event);
+  EXPECT_EQ(event.button, normalized_event.button);
+  EXPECT_EQ(event.GetModifiers(), normalized_event.GetModifiers());
+  EXPECT_EQ(event.GetType(), normalized_event.GetType());
+}
+
+}  // namespace
+
+TEST(InputUtilsTest, NormalizeMouseEventLeftMouseDown) {
+  CheckNormalizeMouseEventIsNoOp(
+      MouseEventBuilder()
+          .SetType(blink::WebInputEvent::Type::kMouseDown)
+          .SetButton(blink::WebPointerProperties::Button::kLeft)
+          .Build());
+}
+
+TEST(InputUtilsTest, NormalizeMouseEventMiddleMouseDown) {
+  CheckNormalizeMouseEventIsNoOp(
+      MouseEventBuilder()
+          .SetType(blink::WebInputEvent::Type::kMouseDown)
+          .SetButton(blink::WebPointerProperties::Button::kMiddle)
+          .Build());
+}
+
+TEST(InputUtilsTest, NormalizeMouseEventRightMouseDown) {
+  CheckNormalizeMouseEventIsNoOp(
+      MouseEventBuilder()
+          .SetType(blink::WebInputEvent::Type::kMouseDown)
+          .SetButton(blink::WebPointerProperties::Button::kRight)
+          .Build());
+}
+
+TEST(InputUtilsTest, NormalizeMouseEventLeftMouseUp) {
+  CheckNormalizeMouseEventIsNoOp(
+      MouseEventBuilder()
+          .SetType(blink::WebInputEvent::Type::kMouseUp)
+          .SetButton(blink::WebPointerProperties::Button::kLeft)
+          .Build());
+}
+
+TEST(InputUtilsTest, NormalizeMouseEventMiddleMouseUp) {
+  CheckNormalizeMouseEventIsNoOp(
+      MouseEventBuilder()
+          .SetType(blink::WebInputEvent::Type::kMouseUp)
+          .SetButton(blink::WebPointerProperties::Button::kMiddle)
+          .Build());
+}
+
+TEST(InputUtilsTest, NormalizeMouseEventRightMouseUp) {
+  CheckNormalizeMouseEventIsNoOp(
+      MouseEventBuilder()
+          .SetType(blink::WebInputEvent::Type::kMouseUp)
+          .SetButton(blink::WebPointerProperties::Button::kRight)
+          .Build());
+}
+
+TEST(InputUtilsTest, NormalizeMouseEventCtrlLeftMouseDown) {
+  blink::WebMouseEvent event =
+      MouseEventBuilder()
+          .SetType(blink::WebInputEvent::Type::kMouseDown)
+          .SetButton(blink::WebPointerProperties::Button::kLeft)
+          .SetModifiers(blink::WebInputEvent::Modifiers::kControlKey)
+          .Build();
+
+#if BUILDFLAG(IS_MAC)
+  blink::WebMouseEvent normalized_event = NormalizeMouseEvent(event);
+  EXPECT_EQ(blink::WebPointerProperties::Button::kRight,
+            normalized_event.button);
+  EXPECT_EQ(blink::WebInputEvent::Modifiers::kRightButtonDown,
+            normalized_event.GetModifiers());
+  EXPECT_EQ(event.GetType(), normalized_event.GetType());
+#else
+  CheckNormalizeMouseEventIsNoOp(event);
+#endif
+}
+
+TEST(InputUtilsTest, NormalizeMouseEventCtrlLefttMouseUp) {
+  CheckNormalizeMouseEventIsNoOp(
+      MouseEventBuilder()
+          .SetType(blink::WebInputEvent::Type::kMouseUp)
+          .SetButton(blink::WebPointerProperties::Button::kLeft)
+          .SetModifiers(blink::WebInputEvent::Modifiers::kControlKey)
+          .Build());
+}
+
+}  // namespace chrome_pdf

pdf/test/mouse_event_builder.cc

@@ -25,6 +25,9 @@ blink::WebMouseEvent MouseEventBuilder::Build() const {
       case blink::WebPointerProperties::Button::kLeft:
         actual_modifiers |= blink::WebInputEvent::Modifiers::kLeftButtonDown;
         break;
+      case blink::WebPointerProperties::Button::kMiddle:
+        actual_modifiers |= blink::WebInputEvent::Modifiers::kMiddleButtonDown;
+        break;
       case blink::WebPointerProperties::Button::kRight:
         actual_modifiers |= blink::WebInputEvent::Modifiers::kRightButtonDown;
         break;