Hitting 'r' in the packager should reload the instance

change/react-native-windows-2020-04-21-14-06-12-master.json

@@ -0,0 +1,8 @@
+{
+  "type": "prerelease",
+  "comment": "Hook up to packager websocket to allow 'r' to reload instance",
+  "packageName": "react-native-windows",
+  "email": "acoates@microsoft.com",
+  "dependentChangeType": "patch",
+  "date": "2020-04-21T21:06:12.961Z"
+}

vnext/Microsoft.ReactNative/ReactHost/ReactInstanceWin.cpp

@@ -513,7 +513,7 @@ std::shared_ptr<IRedBoxHandler> ReactInstanceWin::GetRedBoxHandler() noexcept {
 
 std::function<void()> ReactInstanceWin::GetLiveReloadCallback() noexcept {
   // Live reload is enabled if we provide a callback function.
-  if (m_options.DeveloperSettings.UseLiveReload) {
+  if (m_options.DeveloperSettings.UseLiveReload || m_options.DeveloperSettings.UseFastRefresh) {
     return Mso::MakeWeakMemberStdFunction(this, &ReactInstanceWin::OnLiveReload);
   }
   return std::function<void()>{};

vnext/ReactUWP/Modules/DevSupportManagerUwp.cpp

@@ -16,6 +16,7 @@
 #include "Utilities.h"
 
 #include <Utils/CppWinrtLessExceptions.h>
+#include <winrt/Windows.Data.Json.h>
 #include <winrt/Windows.Storage.Streams.h>
 #include <winrt/Windows.Web.Http.Filters.h>
 #include <winrt/Windows.Web.Http.Headers.h>
@@ -73,12 +74,64 @@ void DevSupportManager::LaunchDevTools(const facebook::react::DevSettings &setti
   DownloadFromAsync(facebook::react::DevServerHelper::get_LaunchDevToolsCommandUrl(settings.debugHost)).get();
 }
 
+std::future<void> DevSupportManager::CreatePackagerConnection(const facebook::react::DevSettings &settings) {
+  m_ws = winrt::Windows::Networking::Sockets::MessageWebSocket();
+
+  m_wsMessageRevoker = m_ws.MessageReceived(
+      winrt::auto_revoke, [reloadCallback = settings.liveReloadCallback](auto && /*sender*/, auto &&args) noexcept {
+        try {
+          auto reader = args.GetDataReader();
+
+          uint32_t len = reader.UnconsumedBufferLength();
+          if (args.MessageType() == winrt::Windows::Networking::Sockets::SocketMessageType::Utf8) {
+            reader.UnicodeEncoding(winrt::Windows::Storage::Streams::UnicodeEncoding::Utf8);
+            std::vector<uint8_t> data(len);
+            reader.ReadBytes(data);
+
+            auto response =
+                std::string(Microsoft::Common::Utilities::CheckedReinterpretCast<char *>(data.data()), data.size());
+            auto json =
+                winrt::Windows::Data::Json::JsonObject::Parse(Microsoft::Common::Unicode::Utf8ToUtf16(response));
+
+            auto version = (int)json.GetNamedNumber(L"version", 0.0);
+            if (version != 2) {
+              return;
+            }
+            auto method = std::wstring(json.GetNamedString(L"method", L""));
+            if (method.empty()) {
+              return;
+            }
+
+            if (!method.compare(L"reload")) {
+              reloadCallback();
+            } else if (!method.compare(L"devMenu")) {
+              // TODO showDevMenu
+            } else if (!method.compare(L"captureHeap")) {
+              // TODO captureHeap
+            }
+          }
+        } catch (winrt::hresult_error const &e) {
+        }
+      });
+
+  winrt::Windows::Foundation::Uri uri(
+      Microsoft::Common::Unicode::Utf8ToUtf16("ws://" + settings.debugHost + "/message"));
+  auto async = m_ws.ConnectAsync(uri);
+
+#ifdef DEFAULT_CPPWINRT_EXCEPTIONS
+  co_await async;
+#else
+  co_await lessthrow_await_adapter<winrt::Windows::Foundation::IAsyncAction>{async};
+#endif
+}
+
 facebook::react::JSECreator DevSupportManager::LoadJavaScriptInProxyMode(const facebook::react::DevSettings &settings) {
   // Reset exception state since client is requesting new service
   m_exceptionCaught = false;
 
   try {
     LaunchDevTools(settings);
+    CreatePackagerConnection(settings);
 
     return [this, settings](
                std::shared_ptr<facebook::react::ExecutorDelegate> delegate,

vnext/ReactUWP/Modules/DevSupportManagerUwp.h

@@ -7,6 +7,7 @@
 
 #include <DevServerHelper.h>
 
+#include <winrt/Windows.Networking.Sockets.h>
 #include <atomic>
 #include <functional>
 #include <memory>
@@ -39,8 +40,11 @@ class DevSupportManager : public facebook::react::IDevSupportManager {
 
  private:
   void LaunchDevTools(const facebook::react::DevSettings &settings);
+  std::future<void> CreatePackagerConnection(const facebook::react::DevSettings &settings);
 
  private:
+  winrt::Windows::Networking::Sockets::MessageWebSocket m_ws{nullptr};
+  winrt::Windows::Networking::Sockets::MessageWebSocket::MessageReceived_revoker m_wsMessageRevoker;
   bool m_exceptionCaught = false;
   std::atomic_bool m_cancellation_token;
 };

vnext/Shared/OInstance.cpp

@@ -661,7 +661,7 @@ std::vector<std::unique_ptr<NativeModule>> InstanceImpl::GetDefaultNativeModules
 
 void InstanceImpl::RegisterForReloadIfNecessary() noexcept {
   // setup polling for live reload
-  if (!m_devManager->HasException() && m_devSettings->liveReloadCallback != nullptr) {
+  if (!m_devManager->HasException() && !m_devSettings->useFastRefresh && m_devSettings->liveReloadCallback != nullptr) {
     m_devManager->StartPollingLiveReload(m_devSettings->debugHost, m_devSettings->liveReloadCallback);
   }
 }