WebApp: Support iteration over all apps in WebAppRegistrar.

Expose Registry as read-only collection.

Users can write:
  for (auto& kv : registrar->registry()) {
    const WebApp* web_app = kv.second.get();
    ...
  }

Add IsEmpty and UnregisterAll methods.

Bug: 891172
Change-Id: I17ad8a5b569eeffb614adeec5575dc6804ce5251
Reviewed-on: https://chromium-review.googlesource.com/c/1295611
Commit-Queue: Alexey Baskakov <loyso@chromium.org>
Reviewed-by: Ben Wells <benwells@chromium.org>
Cr-Commit-Position: refs/heads/master@{#601855}

chrome/browser/web_applications/web_app_registrar.cc

@@ -37,4 +37,8 @@ WebApp* WebAppRegistrar::GetAppById(const AppId& app_id) {
   return kv == registry_.end() ? nullptr : kv->second.get();
 }
 
+void WebAppRegistrar::UnregisterAll() {
+  registry_.clear();
+}
+
 }  // namespace web_app

chrome/browser/web_applications/web_app_registrar.h

@@ -25,8 +25,16 @@ class WebAppRegistrar {
 
   WebApp* GetAppById(const AppId& app_id);
 
+  using Registry = std::map<AppId, std::unique_ptr<WebApp>>;
+  const Registry& registry() const { return registry_; }
+
+  bool is_empty() const { return registry_.empty(); }
+
+  // Clears registry.
+  void UnregisterAll();
+
  private:
-  std::map<AppId, std::unique_ptr<WebApp>> registry_;
+  Registry registry_;
 
   DISALLOW_COPY_AND_ASSIGN(WebAppRegistrar);
 };

chrome/browser/web_applications/web_app_registrar_unittest.cc

@@ -4,6 +4,9 @@
 
 #include "chrome/browser/web_applications/web_app_registrar.h"
 
+#include <set>
+
+#include "base/strings/string_number_conversions.h"
 #include "chrome/browser/web_applications/components/web_app_helpers.h"
 #include "chrome/browser/web_applications/web_app.h"
 #include "testing/gtest/include/gtest/gtest.h"
@@ -11,6 +14,27 @@
 
 namespace web_app {
 
+namespace {
+
+std::set<AppId> RegisterAppsForTesting(const std::string& base_url,
+                                       int num_apps,
+                                       WebAppRegistrar* registrar) {
+  std::set<AppId> ids;
+
+  for (int i = 0; i < num_apps; ++i) {
+    const auto url = base_url + base::IntToString(i);
+    const AppId app_id = GenerateAppIdFromURL(GURL(url));
+    auto web_app = std::make_unique<WebApp>(app_id);
+    registrar->RegisterApp(std::move(web_app));
+
+    ids.insert(app_id);
+  }
+
+  return ids;
+}
+
+}  // namespace
+
 TEST(WebAppRegistrar, CreateRegisterUnregister) {
   auto registrar = std::make_unique<WebAppRegistrar>();
   EXPECT_EQ(nullptr, registrar->GetAppById(AppId()));
@@ -32,6 +56,7 @@ TEST(WebAppRegistrar, CreateRegisterUnregister) {
 
   EXPECT_EQ(nullptr, registrar->GetAppById(app_id));
   EXPECT_EQ(nullptr, registrar->GetAppById(app_id2));
+  EXPECT_TRUE(registrar->is_empty());
 
   registrar->RegisterApp(std::move(web_app));
   WebApp* app = registrar->GetAppById(app_id);
@@ -42,13 +67,16 @@ TEST(WebAppRegistrar, CreateRegisterUnregister) {
   EXPECT_EQ(launch_url.spec(), app->launch_url());
 
   EXPECT_EQ(nullptr, registrar->GetAppById(app_id2));
+  EXPECT_FALSE(registrar->is_empty());
 
   registrar->RegisterApp(std::move(web_app2));
   WebApp* app2 = registrar->GetAppById(app_id2);
   EXPECT_EQ(app_id2, app2->app_id());
+  EXPECT_FALSE(registrar->is_empty());
 
   registrar->UnregisterApp(app_id);
   EXPECT_EQ(nullptr, registrar->GetAppById(app_id));
+  EXPECT_FALSE(registrar->is_empty());
 
   // Check that app2 is still registered.
   app2 = registrar->GetAppById(app_id2);
@@ -56,6 +84,7 @@ TEST(WebAppRegistrar, CreateRegisterUnregister) {
 
   registrar->UnregisterApp(app_id2);
   EXPECT_EQ(nullptr, registrar->GetAppById(app_id2));
+  EXPECT_TRUE(registrar->is_empty());
 }
 
 TEST(WebAppRegistrar, DestroyRegistrarOwningRegisteredApps) {
@@ -73,4 +102,23 @@ TEST(WebAppRegistrar, DestroyRegistrarOwningRegisteredApps) {
   registrar.reset();
 }
 
+TEST(WebAppRegistrar, ForEachAndUnregisterAll) {
+  auto registrar = std::make_unique<WebAppRegistrar>();
+
+  auto ids =
+      RegisterAppsForTesting("https://example.com/path", 100, registrar.get());
+  EXPECT_EQ(100UL, ids.size());
+
+  for (auto& kv : registrar->registry()) {
+    const WebApp* web_app = kv.second.get();
+    const size_t num_removed = ids.erase(web_app->app_id());
+    EXPECT_EQ(1U, num_removed);
+  }
+  EXPECT_TRUE(ids.empty());
+
+  EXPECT_FALSE(registrar->is_empty());
+  registrar->UnregisterAll();
+  EXPECT_TRUE(registrar->is_empty());
+}
+
 }  // namespace web_app