Implement a dbus client for CupsTool.

chromeos/dbus/cups_client_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 "chromeos/dbus/cups_client.h"
+
+#include <memory>
+
+#include "base/bind.h"
+#include "dbus/mock_bus.h"
+#include "dbus/mock_object_proxy.h"
+#include "testing/gtest/include/gtest/gtest.h"
+#include "third_party/cros_system_api/dbus/debugd/dbus-constants.h"
+
+namespace chromeos {
+
+using testing::_;
+using testing::Return;
+
+namespace {
+
+class CallbackHelper {
+ public:
+  CallbackHelper()
+      : callback_called_(false), error_called_(false), weak_factory_(this) {}
+
+  CupsClient::AddPrinterCallback MockAddCallback();
+  CupsClient::RemovePrinterCallback MockRemoveCallback();
+  base::Closure MockErrorCallback();
+
+  bool error_called() const;
+  bool callback_called() const;
+  bool actual_result() const;
+
+ private:
+  void RecordResult(bool result);
+  void ErrorStub();
+
+  // The result of the callback.
+  bool actual_result_;
+
+  bool callback_called_;
+  bool error_called_;
+
+  base::WeakPtrFactory<CallbackHelper> weak_factory_;
+};
+
+CupsClient::AddPrinterCallback CallbackHelper::MockAddCallback() {
+  return base::Bind(&CallbackHelper::RecordResult, weak_factory_.GetWeakPtr());
+}
+
+CupsClient::RemovePrinterCallback CallbackHelper::MockRemoveCallback() {
+  return base::Bind(&CallbackHelper::RecordResult, weak_factory_.GetWeakPtr());
+}
+
+base::Closure CallbackHelper::MockErrorCallback() {
+  return base::Bind(&CallbackHelper::ErrorStub, weak_factory_.GetWeakPtr());
+}
+
+bool CallbackHelper::error_called() const {
+  return error_called_;
+}
+
+bool CallbackHelper::callback_called() const {
+  return callback_called_;
+}
+
+bool CallbackHelper::actual_result() const {
+  return actual_result_;
+}
+
+void CallbackHelper::RecordResult(bool result) {
+  actual_result_ = result;
+  callback_called_ = true;
+}
+
+void CallbackHelper::ErrorStub() {
+  error_called_ = true;
+}
+
+void NopVerify(dbus::MessageReader* reader) {}
+
+void VerifyAddArgs(const std::string& name,
+                   const std::string& uri,
+                   const std::string& ppd,
+                   const bool everywhere,
+                   dbus::MessageReader* reader) {
+  ASSERT_NE(nullptr, reader);
+
+  std::string actual_name;
+  std::string actual_uri;
+  std::string actual_ppd;
+  bool actual_everywhere;
+
+  ASSERT_TRUE(reader->PopString(&actual_name));
+  EXPECT_EQ(name, actual_name);
+
+  ASSERT_TRUE(reader->PopString(&actual_uri));
+  EXPECT_EQ(uri, actual_uri);
+
+  ASSERT_TRUE(reader->PopString(&actual_ppd));
+  EXPECT_EQ(ppd, actual_ppd);
+
+  ASSERT_TRUE(reader->PopBool(&actual_everywhere));
+  EXPECT_EQ(everywhere, actual_everywhere);
+
+  EXPECT_FALSE(reader->HasMoreData());
+}
+
+void VerifyRemoveArgs(const std::string& name, dbus::MessageReader* reader) {
+  ASSERT_NE(nullptr, reader);
+
+  std::string actual_name;
+  ASSERT_TRUE(reader->PopString(&actual_name));
+  EXPECT_EQ(name, actual_name);
+
+  EXPECT_FALSE(reader->HasMoreData());
+}
+
+}  // namespace
+
+class CupsClientTest : public testing::Test {
+ public:
+  CupsClientTest() {}
+
+  void SetUp() override {
+    // Create a mock bus.
+    dbus::Bus::Options options;
+    options.bus_type = dbus::Bus::SYSTEM;
+    mock_bus_ = new dbus::MockBus(options);
+
+    // Create a mock cups proxy.
+    mock_cups_proxy_ =
+        new dbus::MockObjectProxy(mock_bus_.get(), debugd::kDebugdInterface,
+                                  dbus::ObjectPath(debugd::kDebugdServicePath));
+
+    // Set an expectation so mock_cups_proxy's CallMethodWithErrorCallback()
+    // will use OnCallMethodWithErrorCallback() to return responses.
+    EXPECT_CALL(*mock_cups_proxy_.get(),
+                CallMethodWithErrorCallback(_, _, _, _))
+        .WillRepeatedly(
+            Invoke(this, &CupsClientTest::OnCallMethodWithErrorCallback));
+
+    // Set an expectation so mock_bus's GetObjectProxy() for the given
+    // service name and the object path will return mock_cups_proxy_.
+    EXPECT_CALL(*mock_bus_.get(),
+                GetObjectProxy("org.chromium.debugd",
+                               dbus::ObjectPath("/org/chromium/debugd")))
+        .WillOnce(Return(mock_cups_proxy_.get()));
+
+    // ShutdownAndBlock() will be called in TearDown().
+    EXPECT_CALL(*mock_bus_.get(), ShutdownAndBlock()).WillOnce(Return());
+
+    // Create a client with the mock bus.
+    client_.reset(CupsClient::Create());
+    client_->Init(mock_bus_.get());
+
+    actual_interface_ = "";
+    actual_method_name_ = "";
+    throw_error_ = false;
+    result_ = false;
+    argument_callback_ = base::Bind(&NopVerify);
+  }
+
+  void TearDown() override { mock_bus_->ShutdownAndBlock(); }
+
+  const std::string& actual_interface() { return actual_interface_; }
+
+  const std::string& actual_method() { return actual_method_name_; }
+
+  CupsClient* client() { return client_.get(); }
+
+  // If |error| is true, the error callback will be triggered
+  // instead of the normal callback.
+  void ThrowError(bool error) { throw_error_ = error; }
+
+  // Set the result for the response.
+  void SetResult(bool result) { result_ = result; }
+
+  void SetArgumentCallback(
+      base::Callback<void(dbus::MessageReader* reader)> callback) {
+    argument_callback_ = callback;
+  }
+
+ private:
+  void OnCallMethodWithErrorCallback(
+      dbus::MethodCall* method_call,
+      int timeout_ms,
+      const dbus::ObjectProxy::ResponseCallback& response_callback,
+      const dbus::ObjectProxy::ErrorCallback& error_callback) {
+    actual_interface_ = method_call->GetInterface();
+    actual_method_name_ = method_call->GetMember();
+    dbus::MessageReader reader(method_call);
+    argument_callback_.Run(&reader);
+    if (throw_error_) {
+      std::unique_ptr<dbus::ErrorResponse> response =
+          dbus::ErrorResponse::FromMethodCall(method_call, "", "");
+      // this will be synchronous so response stays in scope.
+      error_callback.Run(response.get());
+      return;
+    }
+
+    std::unique_ptr<dbus::Response> response(dbus::Response::CreateEmpty());
+    dbus::MessageWriter writer(response.get());
+    writer.AppendBool(result_);
+    response_callback.Run(response.get());
+  }
+
+  // The interface of the called method.
+  std::string actual_interface_;
+
+  // The name of the method which was called.
+  std::string actual_method_name_;
+
+  // The client to be tested.
+  std::unique_ptr<CupsClient> client_;
+
+  // The mock bus.
+  scoped_refptr<dbus::MockBus> mock_bus_;
+
+  // The mock object proxy.
+  scoped_refptr<dbus::MockObjectProxy> mock_cups_proxy_;
+
+  base::Callback<void(dbus::MessageReader*)> argument_callback_;
+
+  bool throw_error_;
+  bool result_;
+};
+
+TEST_F(CupsClientTest, AddPrinterCallsAdd) {

[hashimoto, 2016/09/07 05:53:17]

Thank you for trying to add test code for this new D-Bus code, but we don't
usually have test code for D-Bus clients as the test tends to be more
complicated than the tested code as you've seen.
Also, the functionality of a D-Bus client cannot be fully verified without
running against the real D-Bus service process on a real Chrome OS device
anyways.

If you feel anxious about adding untested code, you can add more granular test
instead (e.g. Move code appending values to MessageWriter into a function, and
have a test of that function), but it's not mandatory.

[skau, 2016/09/09 15:25:32]

Okay.  We're going to cover this with an integration test down the line so I'm
not too worried.  I have a test harness to verify that it works.

+  CallbackHelper helper;
+  client()->AddPrinter("printer name", "ipp://1.1.1.1", "", true,
+                       helper.MockAddCallback(), helper.MockErrorCallback());
+  EXPECT_EQ("org.chromium.debugd", actual_interface());
+  EXPECT_EQ("CupsAddPrinter", actual_method());
+}
+
+TEST_F(CupsClientTest, AddPrinterCallbackIsCalled) {
+  CallbackHelper helper;
+  ThrowError(false);
+  SetResult(true);
+
+  client()->AddPrinter("printer name", "ipp://1.1.1.1", "", true,
+                       helper.MockAddCallback(), helper.MockErrorCallback());
+  EXPECT_TRUE(helper.callback_called());
+  EXPECT_TRUE(helper.actual_result());
+}
+
+TEST_F(CupsClientTest, AddPrinterArgumentsPassed) {
+  CallbackHelper helper;
+  std::string printer_name = "added printer";
+  std::string uri = "ipp://printer-p.com/";
+  std::string ppd = "/manufacturer/model/filename.ppd";
+  bool everywhere = false;
+  SetArgumentCallback(
+      base::Bind(&VerifyAddArgs, printer_name, uri, ppd, everywhere));
+
+  client()->AddPrinter(printer_name, uri, ppd, everywhere,
+                       helper.MockRemoveCallback(), helper.MockErrorCallback());
+}
+
+TEST_F(CupsClientTest, AddCallsError) {
+  CallbackHelper helper;
+  ThrowError(true);
+
+  client()->AddPrinter("printer name", "ipp://1.1.1.1", "", true,
+                       helper.MockAddCallback(), helper.MockErrorCallback());
+
+  EXPECT_TRUE(helper.error_called());
+  EXPECT_FALSE(helper.callback_called());
+}
+
+TEST_F(CupsClientTest, RemovePrinterCallsRemove) {
+  CallbackHelper helper;
+  client()->RemovePrinter("printer name", helper.MockRemoveCallback(),
+                          helper.MockErrorCallback());
+  EXPECT_EQ("org.chromium.debugd", actual_interface());
+  EXPECT_EQ("CupsRemovePrinter", actual_method());
+}
+
+TEST_F(CupsClientTest, RemovePrinterCallbackIsCalled) {
+  CallbackHelper helper;
+  ThrowError(false);
+  SetResult(false);
+
+  client()->RemovePrinter("printer", helper.MockRemoveCallback(),
+                          helper.MockErrorCallback());
+  EXPECT_TRUE(helper.callback_called());
+  EXPECT_FALSE(helper.actual_result());
+}
+
+TEST_F(CupsClientTest, RemoveCallsError) {
+  CallbackHelper helper;
+  ThrowError(true);
+
+  client()->RemovePrinter("Printer", helper.MockRemoveCallback(),
+                          helper.MockErrorCallback());
+
+  EXPECT_TRUE(helper.error_called());
+  EXPECT_FALSE(helper.callback_called());
+}
+
+TEST_F(CupsClientTest, RemovePrinterArgumentsPassed) {
+  CallbackHelper helper;
+  std::string printer_name = "deletable printer";
+  SetArgumentCallback(base::Bind(&VerifyRemoveArgs, printer_name));
+
+  client()->RemovePrinter(printer_name, helper.MockRemoveCallback(),
+                          helper.MockErrorCallback());
+}
+
+}  // namespace chromeos