Bug 1716560 - Create C++ API for NimbusFeatures r=emilio

Differential Revision: https://phabricator.services.mozilla.com/D117339

toolkit/components/nimbus/lib/NimbusFeatures.cpp

@@ -0,0 +1,60 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "mozilla/browser/NimbusFeatures.h"
+
+namespace mozilla {
+
+void NimbusFeatures::GetPrefName(const nsACString& aFeatureId,
+                                 const nsACString& aVariable,
+                                 nsACString& aPref) {
+  // This branch is used to store experiment data
+  constexpr auto kSyncDataPrefBranch = "nimbus.syncdatastore."_ns;
+  aPref.Truncate();
+  aPref.Append(kSyncDataPrefBranch);
+  aPref.Append(aFeatureId);
+  aPref.Append(".");
+  aPref.Append(aVariable);
+}
+
+void NimbusFeatures::PreferencesCallback(const char* aPref, void* aData) {
+  PrefChangedFunc cb = reinterpret_cast<PrefChangedFunc>(aData);
+  (*cb)(aPref, nullptr);
+}
+
+bool NimbusFeatures::GetBool(const nsACString& aFeatureId,
+                             const nsACString& aVariable, bool aDefault) {
+  nsAutoCString pref;
+  GetPrefName(aFeatureId, aVariable, pref);
+  return Preferences::GetBool(pref.get(), aDefault);
+}
+
+int NimbusFeatures::GetInt(const nsACString& aFeatureId,
+                           const nsACString& aVariable, int aDefault) {
+  nsAutoCString pref;
+  GetPrefName(aFeatureId, aVariable, pref);
+  return Preferences::GetInt(pref.get(), aDefault);
+}
+
+nsresult NimbusFeatures::OnUpdate(const nsACString& aFeatureId,
+                                  const nsACString& aVariable,
+                                  PrefChangedFunc aUserCallback) {
+  nsAutoCString pref;
+  GetPrefName(aFeatureId, aVariable, pref);
+  return Preferences::RegisterCallback(PreferencesCallback, pref,
+                                       (void*)aUserCallback);
+}
+
+nsresult NimbusFeatures::OffUpdate(const nsACString& aFeatureId,
+                                   const nsACString& aVariable,
+                                   PrefChangedFunc aUserCallback) {
+  nsAutoCString pref;
+  GetPrefName(aFeatureId, aVariable, pref);
+  return Preferences::UnregisterCallback(
+      PreferencesCallback, pref, reinterpret_cast<void*>(aUserCallback));
+}
+
+}  // namespace mozilla

toolkit/components/nimbus/lib/NimbusFeatures.h

@@ -0,0 +1,41 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_NimbusFeatures_h
+#define mozilla_NimbusFeatures_h
+
+#include "mozilla/Preferences.h"
+
+namespace mozilla {
+
+class NimbusFeatures {
+  using PrefChangedFunc = void (*)(const char* aPref, void* aData);
+
+ private:
+  static void GetPrefName(const nsACString& aFeatureId,
+                          const nsACString& aVariable, nsACString& aPref);
+
+  static void PreferencesCallback(const char* aPref, void* aData);
+
+ public:
+  static bool GetBool(const nsACString& aFeatureId, const nsACString& aVariable,
+                      bool aDefault);
+
+  static int GetInt(const nsACString& aFeatureId, const nsACString& aVariable,
+                    int aDefault);
+
+  static nsresult OnUpdate(const nsACString& aFeatureId,
+                           const nsACString& aVariable,
+                           PrefChangedFunc aUserCallback);
+
+  static nsresult OffUpdate(const nsACString& aFeatureId,
+                            const nsACString& aVariable,
+                            PrefChangedFunc aUserCallback);
+};
+
+}  // namespace mozilla
+
+#endif

toolkit/components/nimbus/moz.build

@@ -7,6 +7,18 @@
 with Files("**"):
     BUG_COMPONENT = ("Firefox", "Nimbus Desktop Client")
 
+EXPORTS.mozilla.browser += [
+    "lib/NimbusFeatures.h",
+]
+
+UNIFIED_SOURCES += [
+    "lib/NimbusFeatures.cpp",
+]
+
+TEST_DIRS += [
+    "test/gtest",
+]
+
 BROWSER_CHROME_MANIFESTS += [
     "test/browser/browser.ini",
 ]
@@ -22,4 +34,6 @@ TESTING_JS_MODULES += [
     "test/NimbusTestUtils.jsm",
 ]
 
+FINAL_LIBRARY = "xul"
+
 JAR_MANIFESTS += ["jar.mn"]

toolkit/components/nimbus/test/gtest/NimbusFeatures_GetTest.cpp

@@ -0,0 +1,33 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "gtest/gtest.h"
+#include "mozilla/Preferences.h"
+#include "mozilla/browser/NimbusFeatures.h"
+#include "mozilla/SpinEventLoopUntil.h"
+
+using namespace mozilla;
+
+static bool gPrefUpdate = false;
+
+TEST(NimbusFeaturesGet, Errors)
+{
+  Preferences::SetInt("nimbus.syncdatastore.foo.value", 42,
+                      PrefValueKind::User);
+  ASSERT_EQ(NimbusFeatures::GetInt("foo"_ns, "value"_ns, 0), 42);
+  Preferences::SetBool("nimbus.syncdatastore.foo.enabled", true,
+                       PrefValueKind::User);
+  ASSERT_TRUE(NimbusFeatures::GetBool("foo"_ns, "enabled"_ns, false));
+}
+
+TEST(NimbusFeaturesUpdate, Errors)
+{
+  NimbusFeatures::OnUpdate("foo"_ns, "value"_ns,
+                           [](const char*, void*) { gPrefUpdate = true; });
+  Preferences::SetInt("nimbus.syncdatastore.foo.value", 24,
+                      PrefValueKind::User);
+  ASSERT_TRUE(gPrefUpdate);
+}

toolkit/components/nimbus/test/gtest/moz.build

@@ -0,0 +1,11 @@
+# -*- Mode: python; indent-tabs-mode: nil; tab-width: 40 -*-
+# vim: set filetype=python:
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+UNIFIED_SOURCES += [
+    "NimbusFeatures_GetTest.cpp",
+]
+
+FINAL_LIBRARY = "xul-gtest"