SnapshotController implementation. It will be used in WebContentsObservers for Offline Pages - to d…

components/offline_pages/snapshot_controller_unittest.cc

+// Copyright 2016 The Chromium 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 "components/offline_pages/snapshot_controller.h"
+
+#include "base/bind.h"
+#include "base/run_loop.h"
+#include "base/single_thread_task_runner.h"
+#include "base/test/test_mock_time_task_runner.h"
+#include "base/thread_task_runner_handle.h"
+#include "base/time/time.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace offline_pages {
+
+class SnapshotControllerTest
+    : public testing::Test,
+      public SnapshotController::Client {
+ public:
+  SnapshotControllerTest();
+  ~SnapshotControllerTest() override;
+
+  SnapshotController* controller() { return controller_.get(); }
+  void set_snapshot_started(bool started) { snapshot_started_ = started; }
+  int snapshot_count() { return snapshot_count_; }
+
+  // testing::Test
+  void SetUp() override;
+  void TearDown() override;
+
+  // SnapshotController::Client
+  bool StartSnapshot() override;
+
+  // Utility methods.
+  // Runs until all of the tasks that are not delayed are gone from the task
+  // queue.
+  void PumpLoop();
+  // Fast-forwards virtual time by |delta|, causing tasks with a remaining
+  // delay less than or equal to |delta| to be executed.
+  void FastForwardBy(base::TimeDelta delta);
+
+ private:
+  std::unique_ptr<SnapshotController> controller_;
+  scoped_refptr<base::TestMockTimeTaskRunner> task_runner_;
+  bool snapshot_started_;
+  int snapshot_count_;
+};
+
+SnapshotControllerTest::SnapshotControllerTest()
+    : task_runner_(new base::TestMockTimeTaskRunner),
+      snapshot_started_(true),
+      snapshot_count_(0) {
+}
+
+SnapshotControllerTest::~SnapshotControllerTest() {
+}
+
+void SnapshotControllerTest::SetUp() {
+  controller_.reset(new SnapshotController(task_runner_, this));
+  snapshot_started_ = true;
+}
+
+void SnapshotControllerTest::TearDown() {
+  controller_.reset();
+}
+
+bool SnapshotControllerTest::StartSnapshot() {
+  snapshot_count_++;
+  return snapshot_started_;
+}
+
+void SnapshotControllerTest::PumpLoop() {
+  task_runner_->RunUntilIdle();
+}
+
+void SnapshotControllerTest::FastForwardBy(base::TimeDelta delta) {
+  task_runner_->FastForwardBy(delta);
+}
+
+TEST_F(SnapshotControllerTest, OnLoad) {
+  // Onload should make snapshot right away.
+  EXPECT_EQ(0, snapshot_count());
+  controller()->DocumentOnLoadCompletedInMainFrame();
+  PumpLoop();
+  EXPECT_EQ(1, snapshot_count());
+}
+
+TEST_F(SnapshotControllerTest, OnDocumentAvailable) {
+  EXPECT_GT(controller()->GetDelayAfterDocumentAvailableForTest(), 0UL);
+  // OnDOM should make snapshot after a delay.
+  controller()->DocumentAvailableInMainFrame();
+  PumpLoop();
+  EXPECT_EQ(0, snapshot_count());
+  FastForwardBy(base::TimeDelta::FromMilliseconds(
+      controller()->GetDelayAfterDocumentAvailableForTest()));
+  EXPECT_EQ(1, snapshot_count());
+}
+
+TEST_F(SnapshotControllerTest, OnLoadSnapshotIsTheLastOne) {
+  // OnDOM should make snapshot after a delay.
+  controller()->DocumentAvailableInMainFrame();
+  PumpLoop();
+  EXPECT_EQ(0, snapshot_count());
+  // This should start snapshot immediately.
+  controller()->DocumentOnLoadCompletedInMainFrame();
+  EXPECT_EQ(1, snapshot_count());
+  // Report that snapshot is completed.
+  controller()->PendingSnapshotCompleted();
+  // Even though previous snapshot is completed, new one should not start
+  // when this delay expires.
+  FastForwardBy(base::TimeDelta::FromMilliseconds(
+      controller()->GetDelayAfterDocumentAvailableForTest()));
+  EXPECT_EQ(1, snapshot_count());
+}
+
+TEST_F(SnapshotControllerTest, OnLoadSnapshotAfterLongDelay) {
+  // OnDOM should make snapshot after a delay.
+  controller()->DocumentAvailableInMainFrame();
+  PumpLoop();
+  EXPECT_EQ(0, snapshot_count());
+  FastForwardBy(base::TimeDelta::FromMilliseconds(
+      controller()->GetDelayAfterDocumentAvailableForTest()));
+  EXPECT_EQ(1, snapshot_count());
+  // Report that snapshot is completed.
+  controller()->PendingSnapshotCompleted();
+  // This should start snapshot immediately.
+  controller()->DocumentOnLoadCompletedInMainFrame();
+  EXPECT_EQ(2, snapshot_count());
+}
+
+TEST_F(SnapshotControllerTest, Stop) {
+  // OnDOM should make snapshot after a delay.
+  controller()->DocumentAvailableInMainFrame();
+  PumpLoop();
+  EXPECT_EQ(0, snapshot_count());
+  controller()->Stop();
+  FastForwardBy(base::TimeDelta::FromMilliseconds(
+      controller()->GetDelayAfterDocumentAvailableForTest()));
+  // Should not start snapshots
+  EXPECT_EQ(0, snapshot_count());
+  // Also should not start snapshot.
+  controller()->DocumentOnLoadCompletedInMainFrame();
+  EXPECT_EQ(0, snapshot_count());
+}
+
+TEST_F(SnapshotControllerTest, ClientDidntStartSnapshot) {
+  // This will tell that Client did not start the snapshot
+  set_snapshot_started(false);
+  controller()->DocumentAvailableInMainFrame();
+  FastForwardBy(base::TimeDelta::FromMilliseconds(
+      controller()->GetDelayAfterDocumentAvailableForTest()));
+  // Should have one snapshot requested, but not reported started.
+  EXPECT_EQ(1, snapshot_count());
+  // Should start another snapshot since previous did not start
+  controller()->DocumentOnLoadCompletedInMainFrame();
+  EXPECT_EQ(2, snapshot_count());
+}
+
+}  // namespace offline_pages