[CrOS Tether] Create HostScanDevicePrioritizer, a class which prioritizes the order of connection a…

chromeos/components/tether/host_scan_device_prioritizer_unittest.cc

Index: chromeos/components/tether/host_scan_device_prioritizer_unittest.cc
diff --git a/chromeos/components/tether/host_scan_device_prioritizer_unittest.cc b/chromeos/components/tether/host_scan_device_prioritizer_unittest.cc
new file mode 100644
index 0000000000000000000000000000000000000000..a61c0c2c46ecde72e2054de02b919bbb70278a57
--- /dev/null
+++ b/chromeos/components/tether/host_scan_device_prioritizer_unittest.cc
@@ -0,0 +1,115 @@
+// 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 "chromeos/components/tether/host_scan_device_prioritizer.h"
+
+#include "components/cryptauth/remote_device_test_util.h"
+#include "components/prefs/testing_pref_service.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace chromeos {
+
+namespace tether {
+
+class HostScanDevicePrioritizerTest : public testing::Test {
+ protected:
+  HostScanDevicePrioritizerTest()
+      : test_devices_(cryptauth::GenerateTestRemoteDevices(10)) {}
+
+  void SetUp() override {
+    pref_service_ = base::MakeUnique<TestingPrefServiceSimple>();
+    HostScanDevicePrioritizer::RegisterPrefs(pref_service_->registry());
+
+    prioritizer_ =
+        base::MakeUnique<HostScanDevicePrioritizer>(pref_service_.get());
+  }
+
+  const std::vector<cryptauth::RemoteDevice> test_devices_;
+
+  std::unique_ptr<TestingPrefServiceSimple> pref_service_;
+  std::unique_ptr<HostScanDevicePrioritizer> prioritizer_;
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(HostScanDevicePrioritizerTest);
+};
+
+TEST_F(HostScanDevicePrioritizerTest, TestOnlyTetherAvailabilityResponses) {
+  // Receive TetherAvailabilityResponses from devices 0-4.
+  prioritizer_->RecordSuccessfulTetherAvailabilityResponse(test_devices_[0]);
+  prioritizer_->RecordSuccessfulTetherAvailabilityResponse(test_devices_[1]);
+  prioritizer_->RecordSuccessfulTetherAvailabilityResponse(test_devices_[2]);
+  prioritizer_->RecordSuccessfulTetherAvailabilityResponse(test_devices_[3]);
+  prioritizer_->RecordSuccessfulTetherAvailabilityResponse(test_devices_[4]);
+
+  // Do not receive a ConnectTetheringResponse.
+
+  std::vector<cryptauth::RemoteDevice> test_vector =
+      std::vector<cryptauth::RemoteDevice>{test_devices_[6], test_devices_[5],
+                                           test_devices_[4], test_devices_[3],
+                                           test_devices_[2], test_devices_[1],
+                                           test_devices_[0]};
+
+  prioritizer_->PrioritizeHostScanDeviceOrder(test_vector);
+  EXPECT_EQ((std::vector<cryptauth::RemoteDevice>{
+                test_devices_[4], test_devices_[3], test_devices_[2],
+                test_devices_[1], test_devices_[0], test_devices_[6],
+                test_devices_[5]}),
+            test_vector);
+}
+
+TEST_F(HostScanDevicePrioritizerTest, TestBothTypesOfResponses) {
+  // Receive TetherAvailabilityResponses from devices 0-4.
+  prioritizer_->RecordSuccessfulTetherAvailabilityResponse(test_devices_[0]);
+  prioritizer_->RecordSuccessfulTetherAvailabilityResponse(test_devices_[1]);
+  prioritizer_->RecordSuccessfulTetherAvailabilityResponse(test_devices_[2]);
+  prioritizer_->RecordSuccessfulTetherAvailabilityResponse(test_devices_[3]);
+  prioritizer_->RecordSuccessfulTetherAvailabilityResponse(test_devices_[4]);
+
+  // Receive ConnectTetheringResponse from device 0.
+  prioritizer_->RecordSuccessfulConnectTetheringResponse(test_devices_[0]);
+
+  std::vector<cryptauth::RemoteDevice> test_vector =
+      std::vector<cryptauth::RemoteDevice>{test_devices_[6], test_devices_[5],
+                                           test_devices_[4], test_devices_[3],
+                                           test_devices_[2], test_devices_[1],
+                                           test_devices_[0]};
+
+  prioritizer_->PrioritizeHostScanDeviceOrder(test_vector);
+  EXPECT_EQ((std::vector<cryptauth::RemoteDevice>{
+                test_devices_[0], test_devices_[4], test_devices_[3],
+                test_devices_[2], test_devices_[1], test_devices_[6],
+                test_devices_[5]}),
+            test_vector);
+}
+
+TEST_F(HostScanDevicePrioritizerTest, TestBothTypesOfResponses_DifferentOrder) {
+  // Receive different order.
+  prioritizer_->RecordSuccessfulTetherAvailabilityResponse(test_devices_[0]);
+  prioritizer_->RecordSuccessfulTetherAvailabilityResponse(test_devices_[2]);
+  prioritizer_->RecordSuccessfulTetherAvailabilityResponse(test_devices_[1]);
+  prioritizer_->RecordSuccessfulTetherAvailabilityResponse(test_devices_[4]);
+  prioritizer_->RecordSuccessfulTetherAvailabilityResponse(test_devices_[3]);
+
+  // Receive ConnectTetheringResponse from device 1.
+  prioritizer_->RecordSuccessfulConnectTetheringResponse(test_devices_[1]);
+
+  std::vector<cryptauth::RemoteDevice> test_vector =
+      std::vector<cryptauth::RemoteDevice>{test_devices_[9], test_devices_[8],
+                                           test_devices_[7], test_devices_[6],
+                                           test_devices_[5], test_devices_[4],
+                                           test_devices_[3], test_devices_[2],
+                                           test_devices_[1], test_devices_[0]};
+
+  prioritizer_->PrioritizeHostScanDeviceOrder(test_vector);
+  EXPECT_EQ((std::vector<cryptauth::RemoteDevice>{
+                test_devices_[1], test_devices_[3], test_devices_[4],
+                test_devices_[2], test_devices_[0], test_devices_[9],
+                test_devices_[8], test_devices_[7], test_devices_[6],
+                test_devices_[5]}),
+            test_vector);
+}
+
+}  // namespace tether
+
+}  // namespace cryptauth