[Windows] Add engine builder to simplify tests (#38546)

* [Windows] Add engine builder to simplify tests

* Format

Author: loic-sharma

shell/platform/windows/BUILD.gn

@@ -199,6 +199,8 @@ executable("flutter_windows_unittests") {
     "testing/engine_modifier.h",
     "testing/flutter_window_test.cc",
     "testing/flutter_window_test.h",
+    "testing/flutter_windows_engine_builder.cc",
+    "testing/flutter_windows_engine_builder.h",
     "testing/mock_direct_manipulation.h",
     "testing/mock_gl_functions.h",
     "testing/mock_text_input_manager.cc",

shell/platform/windows/flutter_windows_engine_unittests.cc

@@ -8,6 +8,7 @@
 #include "flutter/shell/platform/embedder/test_utils/proc_table_replacement.h"
 #include "flutter/shell/platform/windows/flutter_windows_view.h"
 #include "flutter/shell/platform/windows/testing/engine_modifier.h"
+#include "flutter/shell/platform/windows/testing/flutter_windows_engine_builder.h"
 #include "flutter/shell/platform/windows/testing/mock_window_binding_handler.h"
 #include "flutter/shell/platform/windows/testing/test_keyboard.h"
 #include "flutter/shell/platform/windows/testing/windows_test.h"
@@ -21,34 +22,14 @@
 namespace flutter {
 namespace testing {
 
-namespace {
-
-// Returns an engine instance configured with dummy project path values.
-std::unique_ptr<FlutterWindowsEngine> GetTestEngine() {
-  FlutterDesktopEngineProperties properties = {};
-  properties.assets_path = L"C:\\foo\\flutter_assets";
-  properties.icu_data_path = L"C:\\foo\\icudtl.dat";
-  properties.aot_library_path = L"C:\\foo\\aot.so";
-
-  std::vector<const char*> test_arguments = {"arg1", "arg2"};
-  properties.dart_entrypoint_argc = test_arguments.size();
-  properties.dart_entrypoint_argv = test_arguments.data();
-
-  FlutterProjectBundle project(properties);
-  auto engine = std::make_unique<FlutterWindowsEngine>(project);
-
-  EngineModifier modifier(engine.get());
-  // Force the non-AOT path unless overridden by the test.
-  modifier.embedder_api().RunsAOTCompiledDartCode = []() { return false; };
-
-  return engine;
-}
-}  // namespace
-
 class FlutterWindowsEngineTest : public WindowsTest {};
 
 TEST_F(FlutterWindowsEngineTest, RunDoesExpectedInitialization) {
-  std::unique_ptr<FlutterWindowsEngine> engine = GetTestEngine();
+  FlutterWindowsEngineBuilder builder{GetContext()};
+  builder.AddDartEntrypointArgument("arg1");
+  builder.AddDartEntrypointArgument("arg2");
+
+  std::unique_ptr<FlutterWindowsEngine> engine = builder.Build();
   EngineModifier modifier(engine.get());
 
   // The engine should be run with expected configuration values.
@@ -67,8 +48,8 @@ TEST_F(FlutterWindowsEngineTest, RunDoesExpectedInitialization) {
         EXPECT_EQ(config->type, kOpenGL);
         EXPECT_EQ(user_data, engine_instance);
         // Spot-check arguments.
-        EXPECT_STREQ(args->assets_path, "C:\\foo\\flutter_assets");
-        EXPECT_STREQ(args->icu_data_path, "C:\\foo\\icudtl.dat");
+        EXPECT_NE(args->assets_path, nullptr);
+        EXPECT_NE(args->icu_data_path, nullptr);
         EXPECT_EQ(args->dart_entrypoint_argc, 2U);
         EXPECT_EQ(strcmp(args->dart_entrypoint_argv[0], "arg1"), 0);
         EXPECT_EQ(strcmp(args->dart_entrypoint_argv[1], "arg2"), 0);
@@ -159,7 +140,8 @@ TEST_F(FlutterWindowsEngineTest, RunDoesExpectedInitialization) {
 }
 
 TEST_F(FlutterWindowsEngineTest, ConfiguresFrameVsync) {
-  std::unique_ptr<FlutterWindowsEngine> engine = GetTestEngine();
+  FlutterWindowsEngineBuilder builder{GetContext()};
+  std::unique_ptr<FlutterWindowsEngine> engine = builder.Build();
   EngineModifier modifier(engine.get());
   bool on_vsync_called = false;
 
@@ -185,7 +167,8 @@ TEST_F(FlutterWindowsEngineTest, ConfiguresFrameVsync) {
 }
 
 TEST_F(FlutterWindowsEngineTest, RunWithoutANGLEUsesSoftware) {
-  std::unique_ptr<FlutterWindowsEngine> engine = GetTestEngine();
+  FlutterWindowsEngineBuilder builder{GetContext()};
+  std::unique_ptr<FlutterWindowsEngine> engine = builder.Build();
   EngineModifier modifier(engine.get());
 
   modifier.embedder_api().NotifyDisplayUpdate =
@@ -237,7 +220,8 @@ TEST_F(FlutterWindowsEngineTest, RunWithoutANGLEUsesSoftware) {
 }
 
 TEST_F(FlutterWindowsEngineTest, SendPlatformMessageWithoutResponse) {
-  std::unique_ptr<FlutterWindowsEngine> engine = GetTestEngine();
+  FlutterWindowsEngineBuilder builder{GetContext()};
+  std::unique_ptr<FlutterWindowsEngine> engine = builder.Build();
   EngineModifier modifier(engine.get());
 
   const char* channel = "test";
@@ -263,14 +247,10 @@ TEST_F(FlutterWindowsEngineTest, SendPlatformMessageWithoutResponse) {
 }
 
 TEST_F(FlutterWindowsEngineTest, PlatformMessageRoundTrip) {
-  FlutterDesktopEngineProperties properties = {};
-  properties.assets_path = GetContext().GetAssetsPath().c_str();
-  properties.icu_data_path = GetContext().GetIcuDataPath().c_str();
-  properties.dart_entrypoint = "hiPlatformChannels";
-
-  FlutterProjectBundle project(properties);
-  auto engine = std::make_unique<FlutterWindowsEngine>(project);
+  FlutterWindowsEngineBuilder builder{GetContext()};
+  builder.SetDartEntrypoint("hiPlatformChannels");
 
+  std::unique_ptr<FlutterWindowsEngine> engine = builder.Build();
   EngineModifier modifier(engine.get());
   modifier.embedder_api().RunsAOTCompiledDartCode = []() { return false; };
 
@@ -312,13 +292,10 @@ TEST_F(FlutterWindowsEngineTest, PlatformMessageRoundTrip) {
 }
 
 TEST_F(FlutterWindowsEngineTest, PlatformMessageRespondOnDifferentThread) {
-  FlutterDesktopEngineProperties properties = {};
-  properties.assets_path = GetContext().GetAssetsPath().c_str();
-  properties.icu_data_path = GetContext().GetIcuDataPath().c_str();
-  properties.dart_entrypoint = "hiPlatformChannels";
+  FlutterWindowsEngineBuilder builder{GetContext()};
+  builder.SetDartEntrypoint("hiPlatformChannels");
 
-  FlutterProjectBundle project(properties);
-  auto engine = std::make_unique<FlutterWindowsEngine>(project);
+  std::unique_ptr<FlutterWindowsEngine> engine = builder.Build();
 
   EngineModifier modifier(engine.get());
   modifier.embedder_api().RunsAOTCompiledDartCode = []() { return false; };
@@ -366,7 +343,8 @@ TEST_F(FlutterWindowsEngineTest, PlatformMessageRespondOnDifferentThread) {
 }
 
 TEST_F(FlutterWindowsEngineTest, SendPlatformMessageWithResponse) {
-  std::unique_ptr<FlutterWindowsEngine> engine = GetTestEngine();
+  FlutterWindowsEngineBuilder builder{GetContext()};
+  std::unique_ptr<FlutterWindowsEngine> engine = builder.Build();
   EngineModifier modifier(engine.get());
 
   const char* channel = "test";
@@ -424,7 +402,8 @@ TEST_F(FlutterWindowsEngineTest, SendPlatformMessageWithResponse) {
 }
 
 TEST_F(FlutterWindowsEngineTest, DispatchSemanticsAction) {
-  std::unique_ptr<FlutterWindowsEngine> engine = GetTestEngine();
+  FlutterWindowsEngineBuilder builder{GetContext()};
+  std::unique_ptr<FlutterWindowsEngine> engine = builder.Build();
   EngineModifier modifier(engine.get());
 
   bool called = false;
@@ -469,7 +448,8 @@ TEST_F(FlutterWindowsEngineTest, SetsThreadPriority) {
 }
 
 TEST_F(FlutterWindowsEngineTest, AddPluginRegistrarDestructionCallback) {
-  std::unique_ptr<FlutterWindowsEngine> engine = GetTestEngine();
+  FlutterWindowsEngineBuilder builder{GetContext()};
+  std::unique_ptr<FlutterWindowsEngine> engine = builder.Build();
   EngineModifier modifier(engine.get());
 
   MockEmbedderApiForKeyboard(modifier,
@@ -499,7 +479,8 @@ TEST_F(FlutterWindowsEngineTest, AddPluginRegistrarDestructionCallback) {
 }
 
 TEST_F(FlutterWindowsEngineTest, ScheduleFrame) {
-  std::unique_ptr<FlutterWindowsEngine> engine = GetTestEngine();
+  FlutterWindowsEngineBuilder builder{GetContext()};
+  std::unique_ptr<FlutterWindowsEngine> engine = builder.Build();
   EngineModifier modifier(engine.get());
 
   bool called = false;
@@ -514,7 +495,8 @@ TEST_F(FlutterWindowsEngineTest, ScheduleFrame) {
 }
 
 TEST_F(FlutterWindowsEngineTest, SetNextFrameCallback) {
-  std::unique_ptr<FlutterWindowsEngine> engine = GetTestEngine();
+  FlutterWindowsEngineBuilder builder{GetContext()};
+  std::unique_ptr<FlutterWindowsEngine> engine = builder.Build();
   EngineModifier modifier(engine.get());
 
   bool called = false;
@@ -529,14 +511,16 @@ TEST_F(FlutterWindowsEngineTest, SetNextFrameCallback) {
 }
 
 TEST_F(FlutterWindowsEngineTest, GetExecutableName) {
-  std::unique_ptr<FlutterWindowsEngine> engine = GetTestEngine();
+  FlutterWindowsEngineBuilder builder{GetContext()};
+  std::unique_ptr<FlutterWindowsEngine> engine = builder.Build();
   EXPECT_EQ(engine->GetExecutableName(), "flutter_windows_unittests.exe");
 }
 
 // Ensure that after setting or resetting the high contrast feature,
 // the corresponding status flag can be retrieved from the engine.
 TEST_F(FlutterWindowsEngineTest, UpdateHighContrastFeature) {
-  std::unique_ptr<FlutterWindowsEngine> engine = GetTestEngine();
+  FlutterWindowsEngineBuilder builder{GetContext()};
+  std::unique_ptr<FlutterWindowsEngine> engine = builder.Build();
   EngineModifier modifier(engine.get());
 
   bool called = false;
@@ -561,7 +545,8 @@ TEST_F(FlutterWindowsEngineTest, UpdateHighContrastFeature) {
 }
 
 TEST_F(FlutterWindowsEngineTest, PostRasterThreadTask) {
-  std::unique_ptr<FlutterWindowsEngine> engine = GetTestEngine();
+  FlutterWindowsEngineBuilder builder{GetContext()};
+  std::unique_ptr<FlutterWindowsEngine> engine = builder.Build();
   EngineModifier modifier(engine.get());
 
   modifier.embedder_api().PostRenderThreadTask = MOCK_ENGINE_PROC(
@@ -586,20 +571,16 @@ class MockFlutterWindowsView : public FlutterWindowsView {
 };
 
 TEST_F(FlutterWindowsEngineTest, AlertPlatformMessage) {
-  FlutterDesktopEngineProperties properties = {};
-  properties.assets_path = GetContext().GetAssetsPath().c_str();
-  properties.icu_data_path = GetContext().GetIcuDataPath().c_str();
-  properties.dart_entrypoint = "alertPlatformChannel";
-
-  FlutterProjectBundle project(properties);
+  FlutterWindowsEngineBuilder builder{GetContext()};
+  builder.SetDartEntrypoint("alertPlatformChannel");
 
   auto window_binding_handler =
       std::make_unique<::testing::NiceMock<MockWindowBindingHandler>>();
   AccessibilityRootNode* root_node = AccessibilityRootNode::Create();
   ON_CALL(*window_binding_handler, GetAccessibilityRootNode)
       .WillByDefault(::testing::Return(root_node));
   MockFlutterWindowsView view(std::move(window_binding_handler));
-  view.SetEngine(std::make_unique<FlutterWindowsEngine>(project));
+  view.SetEngine(builder.Build());
   FlutterWindowsEngine* engine = view.GetEngine();
 
   EngineModifier modifier(engine);

shell/platform/windows/platform_handler_unittests.cc

@@ -8,8 +8,10 @@
 
 #include "flutter/shell/platform/common/json_method_codec.h"
 #include "flutter/shell/platform/windows/flutter_windows_view.h"
+#include "flutter/shell/platform/windows/testing/flutter_windows_engine_builder.h"
 #include "flutter/shell/platform/windows/testing/mock_window_binding_handler.h"
 #include "flutter/shell/platform/windows/testing/test_binary_messenger.h"
+#include "flutter/shell/platform/windows/testing/windows_test.h"
 #include "gmock/gmock.h"
 #include "gtest/gtest.h"
 #include "rapidjson/document.h"
@@ -95,26 +97,22 @@ std::string SimulatePlatformMessage(TestBinaryMessenger* messenger,
 
 }  // namespace
 
-class PlatformHandlerTest : public ::testing::Test {
+class PlatformHandlerTest : public WindowsTest {
  protected:
   FlutterWindowsEngine* engine() { return engine_.get(); }
 
   void use_headless_engine() {
-    // Set properties required to create the engine.
-    FlutterDesktopEngineProperties properties = {};
-    properties.assets_path = L"C:\\foo\\flutter_assets";
-    properties.icu_data_path = L"C:\\foo\\icudtl.dat";
-    properties.aot_library_path = L"C:\\foo\\aot.so";
-    FlutterProjectBundle project(properties);
-
-    engine_ = std::make_unique<FlutterWindowsEngine>(project);
+    FlutterWindowsEngineBuilder builder{GetContext()};
+
+    engine_ = builder.Build();
   }
 
   void use_engine_with_view() {
-    use_headless_engine();
+    FlutterWindowsEngineBuilder builder{GetContext()};
 
     auto window = std::make_unique<NiceMock<MockWindowBindingHandler>>();
     view_ = std::make_unique<FlutterWindowsView>(std::move(window));
+    engine_ = builder.Build();
 
     engine_->SetView(view_.get());
   }

shell/platform/windows/testing/flutter_windows_engine_builder.cc

@@ -0,0 +1,51 @@
+// Copyright 2013 The Flutter 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 "flutter/shell/platform/windows/testing/flutter_windows_engine_builder.h"
+
+namespace flutter {
+namespace testing {
+
+FlutterWindowsEngineBuilder::FlutterWindowsEngineBuilder(
+    WindowsTestContext& context)
+    : context_(context) {
+  properties_.assets_path = context.GetAssetsPath().c_str();
+  properties_.icu_data_path = context.GetIcuDataPath().c_str();
+  properties_.aot_library_path = context.GetAotLibraryPath().c_str();
+}
+
+FlutterWindowsEngineBuilder::~FlutterWindowsEngineBuilder() = default;
+
+void FlutterWindowsEngineBuilder::SetDartEntrypoint(std::string entrypoint) {
+  dart_entrypoint_ = std::move(entrypoint);
+  properties_.dart_entrypoint = dart_entrypoint_.c_str();
+}
+
+void FlutterWindowsEngineBuilder::AddDartEntrypointArgument(std::string arg) {
+  dart_entrypoint_arguments_.emplace_back(std::move(arg));
+}
+
+std::unique_ptr<FlutterWindowsEngine> FlutterWindowsEngineBuilder::Build() {
+  std::vector<const char*> dart_args;
+  dart_args.reserve(dart_entrypoint_arguments_.size());
+
+  for (const auto& arg : dart_entrypoint_arguments_) {
+    dart_args.push_back(arg.c_str());
+  }
+
+  if (!dart_args.empty()) {
+    properties_.dart_entrypoint_argv = dart_args.data();
+    properties_.dart_entrypoint_argc = dart_args.size();
+  } else {
+    properties_.dart_entrypoint_argv = nullptr;
+    properties_.dart_entrypoint_argc = 0;
+  }
+
+  FlutterProjectBundle project(properties_);
+
+  return std::make_unique<FlutterWindowsEngine>(project);
+}
+
+}  // namespace testing
+}  // namespace flutter

shell/platform/windows/testing/flutter_windows_engine_builder.h

@@ -0,0 +1,43 @@
+// Copyright 2013 The Flutter Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef FLUTTER_SHELL_PLATFORM_WINDOWS_TESTING_FLUTTER_WINDOWS_ENGINE_BUILDER_H_
+#define FLUTTER_SHELL_PLATFORM_WINDOWS_TESTING_FLUTTER_WINDOWS_ENGINE_BUILDER_H_
+
+#include <memory>
+
+#include "flutter/shell/platform/windows/flutter_windows_engine.h"
+#include "flutter/shell/platform/windows/public/flutter_windows.h"
+#include "flutter/shell/platform/windows/testing/windows_test_context.h"
+
+namespace flutter {
+namespace testing {
+
+class FlutterWindowsEngineBuilder {
+ public:
+  explicit FlutterWindowsEngineBuilder(WindowsTestContext& context);
+  ~FlutterWindowsEngineBuilder();
+
+  void SetDartEntrypoint(std::string entrypoint);
+
+  void AddDartEntrypointArgument(std::string arg);
+
+  std::unique_ptr<FlutterWindowsEngine> Build();
+
+  // Prevent copying.
+  FlutterWindowsEngineBuilder(FlutterWindowsEngineBuilder const&) = delete;
+  FlutterWindowsEngineBuilder& operator=(FlutterWindowsEngineBuilder const&) =
+      delete;
+
+ private:
+  WindowsTestContext& context_;
+  FlutterDesktopEngineProperties properties_ = {};
+  std::string dart_entrypoint_;
+  std::vector<std::string> dart_entrypoint_arguments_;
+};
+
+}  // namespace testing
+}  // namespace flutter
+
+#endif  // FLUTTER_SHELL_PLATFORM_WINDOWS_TESTING_FLUTTER_WINDOWS_ENGINE_BUILDER_H_

shell/platform/windows/testing/windows_test_context.cc

@@ -31,6 +31,10 @@ const std::wstring& WindowsTestContext::GetIcuDataPath() const {
   return icu_data_path_;
 }
 
+const std::wstring& WindowsTestContext::GetAotLibraryPath() const {
+  return aot_library_path_;
+}
+
 void WindowsTestContext::AddNativeFunction(std::string_view name,
                                            Dart_NativeFunction function) {
   native_resolver_->AddNativeCallback(std::string{name}, function);