remoting/host/file_transfer/local_file_operations_unittest.cc - chromium/src - Git at Google

 // Copyright 2018 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 "remoting/host/file_transfer/local_file_operations.h"

 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/containers/queue.h"
 #include "base/files/file_util.h"
 #include "base/path_service.h"
 #include "base/test/scoped_path_override.h"
 #include "base/test/task_environment.h"
 #include "remoting/host/file_transfer/fake_file_chooser.h"
 #include "testing/gtest/include/gtest/gtest.h"

 namespace remoting {

 namespace {

 // BindOnce disallows binding lambdas with captures. This is reasonable in
 // production code, as it requires one to either explicitly pass owned objects
 // or pointers using Owned, Unretained, et cetera. This helps to avoid use-
 // after-free bugs in async code. In test code, though, where the lambda is
 // immediately invoked in the test method using, e.g., RunUntilIdle, the ability
 // to capture can make the code much easier to read and write.
 template <typename T>
 auto BindLambda(T lambda) {
   return base::BindOnce(&T::operator(),
                         base::Owned(new auto(std::move(lambda))));
 }

 }  // namespace

 class LocalFileOperationsTest : public testing::Test {
  public:
   LocalFileOperationsTest();

   // testing::Test implementation.
   void SetUp() override;
   void TearDown() override;

  protected:
   const base::FilePath kTestFilename =
       base::FilePath::FromUTF8Unsafe("test-file.txt");
   const base::FilePath kTestFilenameSecondary =
       base::FilePath::FromUTF8Unsafe("test-file (1).txt");
   const base::FilePath kTestFilenameTertiary =
       base::FilePath::FromUTF8Unsafe("test-file (2).txt");
   const std::string kTestDataOne = "this is the first test string";
   const std::string kTestDataTwo = "this is the second test string";
   const std::string kTestDataThree = "this is the third test string";

   base::FilePath TestDir();
   void WriteFile(const base::FilePath& filename,
                  base::queue<std::string> chunks,
                  bool close);
   void OnOperationComplete(base::queue<std::string> remaining_chunks,
                            bool close,
                            FileOperations::Writer::Result result);
   void OnCloseComplete(FileOperations::Writer::Result result);

   // Points DIR_USER_DESKTOP at a scoped temporary directory.
   base::ScopedPathOverride scoped_path_override_;
   base::test::TaskEnvironment task_environment_;
   std::unique_ptr<FileOperations> file_operations_;
   std::unique_ptr<FileOperations::Writer> file_writer_;
   bool operation_completed_ = false;
 };

 LocalFileOperationsTest::LocalFileOperationsTest()
     : scoped_path_override_(base::DIR_USER_DESKTOP),
       task_environment_(
           base::test::TaskEnvironment::MainThreadType::DEFAULT,
           base::test::TaskEnvironment::ThreadPoolExecutionMode::QUEUED),
       file_operations_(std::make_unique<LocalFileOperations>(
           task_environment_.GetMainThreadTaskRunner())) {}

 void LocalFileOperationsTest::SetUp() {}

 void LocalFileOperationsTest::TearDown() {}

 base::FilePath LocalFileOperationsTest::TestDir() {
   base::FilePath result;
   EXPECT_TRUE(base::PathService::Get(base::DIR_USER_DESKTOP, &result));
   return result;
 }

 void LocalFileOperationsTest::WriteFile(const base::FilePath& filename,
                                         base::queue<std::string> chunks,
                                         bool close) {
   operation_completed_ = false;
   file_writer_ = file_operations_->CreateWriter();
   file_writer_->Open(
       filename,
       base::BindOnce(&LocalFileOperationsTest::OnOperationComplete,
                      base::Unretained(this), std::move(chunks), close));
 }

 void LocalFileOperationsTest::OnOperationComplete(
     base::queue<std::string> remaining_chunks,
     bool close,
     FileOperations::Writer::Result result) {
   ASSERT_TRUE(result);
   if (!remaining_chunks.empty()) {
     std::string next_chunk = std::move(remaining_chunks.front());
     remaining_chunks.pop();
     file_writer_->WriteChunk(
         std::move(next_chunk),
         base::BindOnce(&LocalFileOperationsTest::OnOperationComplete,
                        base::Unretained(this), std::move(remaining_chunks),
                        close));
   } else if (close) {
     file_writer_->Close(base::BindOnce(
         &LocalFileOperationsTest::OnCloseComplete, base::Unretained(this)));
   } else {
     operation_completed_ = true;
   }
 }

 void LocalFileOperationsTest::OnCloseComplete(
     FileOperations::Writer::Result result) {
   ASSERT_TRUE(result);
   operation_completed_ = true;
 }

 // Verifies that a file consisting of three chunks can be written successfully.
 TEST_F(LocalFileOperationsTest, WritesThreeChunks) {
   WriteFile(
       kTestFilename,
       base::queue<std::string>({kTestDataOne, kTestDataTwo, kTestDataThree}),
       true /* close */);
   task_environment_.RunUntilIdle();
   ASSERT_TRUE(operation_completed_);

   std::string actual_file_data;
   ASSERT_TRUE(base::ReadFileToString(TestDir().Append(kTestFilename),
                                      &actual_file_data));
   ASSERT_EQ(kTestDataOne + kTestDataTwo + kTestDataThree, actual_file_data);
 }

 // Verifies that LocalFileOperations will write to a file named "file (1).txt"
 // if "file.txt" already exists, and "file (2).txt" after that.
 TEST_F(LocalFileOperationsTest, RenamesFileIfExists) {
   WriteFile(kTestFilename, base::queue<std::string>({kTestDataOne}),
             true /* close */);
   task_environment_.RunUntilIdle();
   EXPECT_TRUE(operation_completed_);

   WriteFile(kTestFilename, base::queue<std::string>({kTestDataTwo}),
             true /* close */);
   task_environment_.RunUntilIdle();
   EXPECT_TRUE(operation_completed_);

   WriteFile(kTestFilename, base::queue<std::string>({kTestDataThree}),
             true /* close */);
   task_environment_.RunUntilIdle();
   EXPECT_TRUE(operation_completed_);

   std::string actual_file_data_one;
   EXPECT_TRUE(base::ReadFileToString(TestDir().Append(kTestFilename),
                                      &actual_file_data_one));
   EXPECT_EQ(kTestDataOne, actual_file_data_one);
   std::string actual_file_data_two;
   EXPECT_TRUE(base::ReadFileToString(TestDir().Append(kTestFilenameSecondary),
                                      &actual_file_data_two));
   EXPECT_EQ(kTestDataTwo, actual_file_data_two);
   std::string actual_file_data_three;
   EXPECT_TRUE(base::ReadFileToString(TestDir().Append(kTestFilenameTertiary),
                                      &actual_file_data_three));
   EXPECT_EQ(kTestDataThree, actual_file_data_three);
 }

 // Verifies that dropping early deletes the temporary file.
 TEST_F(LocalFileOperationsTest, DroppingDeletesTemp) {
   WriteFile(
       kTestFilename,
       base::queue<std::string>({kTestDataOne, kTestDataTwo, kTestDataThree}),
       false /* close */);
   task_environment_.RunUntilIdle();
   ASSERT_TRUE(operation_completed_);

   file_writer_.reset();
   task_environment_.RunUntilIdle();

   ASSERT_TRUE(base::IsDirectoryEmpty(TestDir()));
 }

 // Verifies that dropping works while an operation is pending.
 TEST_F(LocalFileOperationsTest, CancelsWhileOperationPending) {
   WriteFile(kTestFilename, base::queue<std::string>({kTestDataOne}),
             false /* close */);
   task_environment_.RunUntilIdle();
   ASSERT_TRUE(operation_completed_);

   file_writer_->WriteChunk(kTestDataTwo, base::DoNothing());
   file_writer_.reset();
   task_environment_.RunUntilIdle();

   ASSERT_TRUE(base::IsDirectoryEmpty(TestDir()));
 }

 // Verifies that a file can be successfully opened for reading.
 TEST_F(LocalFileOperationsTest, OpensReader) {
   base::FilePath path = TestDir().Append(kTestFilename);
   std::string contents = kTestDataOne + kTestDataTwo + kTestDataThree;
   ASSERT_EQ(static_cast<int>(contents.size()),
             base::WriteFile(path, contents.data(), contents.size()));

   std::unique_ptr<FileOperations::Reader> reader =
       file_operations_->CreateReader();

   FakeFileChooser::SetResult(path);
   base::Optional<FileOperations::Reader::OpenResult> open_result;
   ASSERT_EQ(FileOperations::kCreated, reader->state());
   reader->Open(BindLambda([&](FileOperations::Reader::OpenResult result) {
     open_result = std::move(result);
   }));
   ASSERT_EQ(FileOperations::kBusy, reader->state());
   task_environment_.RunUntilIdle();
   EXPECT_EQ(FileOperations::kReady, reader->state());
   ASSERT_TRUE(open_result);
   ASSERT_TRUE(*open_result);
   EXPECT_EQ(kTestFilename, reader->filename());
   EXPECT_EQ(contents.size(), reader->size());
 }

 // Verifies that a file can be successfully read in three chunks.
 TEST_F(LocalFileOperationsTest, ReadsThreeChunks) {
   base::FilePath path = TestDir().Append(kTestFilename);
   std::string contents = kTestDataOne + kTestDataTwo + kTestDataThree;
   ASSERT_EQ(static_cast<int>(contents.size()),
             base::WriteFile(path, contents.data(), contents.size()));

   std::unique_ptr<FileOperations::Reader> reader =
       file_operations_->CreateReader();

   FakeFileChooser::SetResult(path);
   base::Optional<FileOperations::Reader::OpenResult> open_result;
   reader->Open(BindLambda([&](FileOperations::Reader::OpenResult result) {
     open_result = std::move(result);
   }));
   task_environment_.RunUntilIdle();
   ASSERT_TRUE(open_result && *open_result);

   for (const auto& chunk : {kTestDataOne, kTestDataTwo, kTestDataThree}) {
     base::Optional<FileOperations::Reader::ReadResult> read_result;
     reader->ReadChunk(
         chunk.size(),
         BindLambda([&](FileOperations::Reader::ReadResult result) {
           read_result = std::move(result);
         }));
     ASSERT_EQ(FileOperations::kBusy, reader->state());
     task_environment_.RunUntilIdle();
     ASSERT_EQ(FileOperations::kReady, reader->state());
     ASSERT_TRUE(read_result);
     ASSERT_TRUE(*read_result);
     EXPECT_EQ(chunk, **read_result);
   }
 }

 // Verifies proper EOF handling.
 TEST_F(LocalFileOperationsTest, ReaderHandlesEof) {
   base::FilePath path = TestDir().Append(kTestFilename);
   std::string contents = kTestDataOne + kTestDataTwo + kTestDataThree;
   ASSERT_EQ(static_cast<int>(contents.size()),
             base::WriteFile(path, contents.data(), contents.size()));

   std::unique_ptr<FileOperations::Reader> reader =
       file_operations_->CreateReader();

   FakeFileChooser::SetResult(path);
   base::Optional<FileOperations::Reader::OpenResult> open_result;
   reader->Open(BindLambda([&](FileOperations::Reader::OpenResult result) {
     open_result = std::move(result);
   }));
   task_environment_.RunUntilIdle();
   ASSERT_TRUE(open_result && *open_result);

   base::Optional<FileOperations::Reader::ReadResult> read_result;
   reader->ReadChunk(
       contents.size() + 5,  // Attempt to read more than is in file.
       BindLambda([&](FileOperations::Reader::ReadResult result) {
         read_result = std::move(result);
       }));
   task_environment_.RunUntilIdle();
   ASSERT_EQ(FileOperations::kReady, reader->state());
   ASSERT_TRUE(read_result && *read_result);
   EXPECT_EQ(contents, **read_result);

   read_result.reset();
   reader->ReadChunk(5,
                     BindLambda([&](FileOperations::Reader::ReadResult result) {
                       read_result = std::move(result);
                     }));
   task_environment_.RunUntilIdle();
   EXPECT_EQ(FileOperations::kComplete, reader->state());
   ASSERT_TRUE(read_result && *read_result);
   EXPECT_EQ(std::size_t{0}, (*read_result)->size());
 }

 // Verifies cancellation is propagated.
 TEST_F(LocalFileOperationsTest, ReaderCancels) {
   std::unique_ptr<FileOperations::Reader> reader =
       file_operations_->CreateReader();

   FakeFileChooser::SetResult(protocol::MakeFileTransferError(
       FROM_HERE, protocol::FileTransfer_Error_Type_CANCELED));
   base::Optional<FileOperations::Reader::OpenResult> open_result;
   reader->Open(BindLambda([&](FileOperations::Reader::OpenResult result) {
     open_result = std::move(result);
   }));
   task_environment_.RunUntilIdle();
   EXPECT_EQ(FileOperations::kFailed, reader->state());
   ASSERT_TRUE(open_result);
   ASSERT_FALSE(*open_result);
   EXPECT_EQ(protocol::FileTransfer_Error_Type_CANCELED,
             open_result->error().type());
 }

 // Verifies failure when file doesn't exist.
 TEST_F(LocalFileOperationsTest, FileNotFound) {
   std::unique_ptr<FileOperations::Reader> reader =
       file_operations_->CreateReader();

   // Currently non-existent file.
   FakeFileChooser::SetResult(TestDir().Append(kTestFilename));
   base::Optional<FileOperations::Reader::OpenResult> open_result;
   reader->Open(BindLambda([&](FileOperations::Reader::OpenResult result) {
     open_result = std::move(result);
   }));
   task_environment_.RunUntilIdle();
   EXPECT_EQ(FileOperations::kFailed, reader->state());
   ASSERT_TRUE(open_result);
   ASSERT_FALSE(*open_result);
 }

 }  // namespace remoting
	// Copyright 2018 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 "remoting/host/file_transfer/local_file_operations.h"

	#include "base/bind.h"
	#include "base/bind_helpers.h"
	#include "base/containers/queue.h"
	#include "base/files/file_util.h"
	#include "base/path_service.h"
	#include "base/test/scoped_path_override.h"
	#include "base/test/task_environment.h"
	#include "remoting/host/file_transfer/fake_file_chooser.h"
	#include "testing/gtest/include/gtest/gtest.h"

	namespace remoting {

	namespace {

	// BindOnce disallows binding lambdas with captures. This is reasonable in
	// production code, as it requires one to either explicitly pass owned objects
	// or pointers using Owned, Unretained, et cetera. This helps to avoid use-
	// after-free bugs in async code. In test code, though, where the lambda is
	// immediately invoked in the test method using, e.g., RunUntilIdle, the ability
	// to capture can make the code much easier to read and write.
	template <typename T>
	auto BindLambda(T lambda) {
	return base::BindOnce(&T::operator(),
	base::Owned(new auto(std::move(lambda))));
	}

	} // namespace

	class LocalFileOperationsTest : public testing::Test {
	public:
	LocalFileOperationsTest();

	// testing::Test implementation.
	void SetUp() override;
	void TearDown() override;

	protected:
	const base::FilePath kTestFilename =
	base::FilePath::FromUTF8Unsafe("test-file.txt");
	const base::FilePath kTestFilenameSecondary =
	base::FilePath::FromUTF8Unsafe("test-file (1).txt");
	const base::FilePath kTestFilenameTertiary =
	base::FilePath::FromUTF8Unsafe("test-file (2).txt");
	const std::string kTestDataOne = "this is the first test string";
	const std::string kTestDataTwo = "this is the second test string";
	const std::string kTestDataThree = "this is the third test string";

	base::FilePath TestDir();
	void WriteFile(const base::FilePath& filename,
	base::queue<std::string> chunks,
	bool close);
	void OnOperationComplete(base::queue<std::string> remaining_chunks,
	bool close,
	FileOperations::Writer::Result result);
	void OnCloseComplete(FileOperations::Writer::Result result);

	// Points DIR_USER_DESKTOP at a scoped temporary directory.
	base::ScopedPathOverride scoped_path_override_;
	base::test::TaskEnvironment task_environment_;
	std::unique_ptr<FileOperations> file_operations_;
	std::unique_ptr<FileOperations::Writer> file_writer_;
	bool operation_completed_ = false;
	};

	LocalFileOperationsTest::LocalFileOperationsTest()
	: scoped_path_override_(base::DIR_USER_DESKTOP),
	task_environment_(
	base::test::TaskEnvironment::MainThreadType::DEFAULT,
	base::test::TaskEnvironment::ThreadPoolExecutionMode::QUEUED),
	file_operations_(std::make_unique<LocalFileOperations>(
	task_environment_.GetMainThreadTaskRunner())) {}

	void LocalFileOperationsTest::SetUp() {}

	void LocalFileOperationsTest::TearDown() {}

	base::FilePath LocalFileOperationsTest::TestDir() {
	base::FilePath result;
	EXPECT_TRUE(base::PathService::Get(base::DIR_USER_DESKTOP, &result));
	return result;
	}

	void LocalFileOperationsTest::WriteFile(const base::FilePath& filename,
	base::queue<std::string> chunks,
	bool close) {
	operation_completed_ = false;
	file_writer_ = file_operations_->CreateWriter();
	file_writer_->Open(
	filename,
	base::BindOnce(&LocalFileOperationsTest::OnOperationComplete,
	base::Unretained(this), std::move(chunks), close));
	}

	void LocalFileOperationsTest::OnOperationComplete(
	base::queue<std::string> remaining_chunks,
	bool close,
	FileOperations::Writer::Result result) {
	ASSERT_TRUE(result);
	if (!remaining_chunks.empty()) {
	std::string next_chunk = std::move(remaining_chunks.front());
	remaining_chunks.pop();
	file_writer_->WriteChunk(
	std::move(next_chunk),
	base::BindOnce(&LocalFileOperationsTest::OnOperationComplete,
	base::Unretained(this), std::move(remaining_chunks),
	close));
	} else if (close) {
	file_writer_->Close(base::BindOnce(
	&LocalFileOperationsTest::OnCloseComplete, base::Unretained(this)));
	} else {
	operation_completed_ = true;
	}
	}

	void LocalFileOperationsTest::OnCloseComplete(
	FileOperations::Writer::Result result) {
	ASSERT_TRUE(result);
	operation_completed_ = true;
	}

	// Verifies that a file consisting of three chunks can be written successfully.
	TEST_F(LocalFileOperationsTest, WritesThreeChunks) {
	WriteFile(
	kTestFilename,
	base::queue<std::string>({kTestDataOne, kTestDataTwo, kTestDataThree}),
	true /* close */);
	task_environment_.RunUntilIdle();
	ASSERT_TRUE(operation_completed_);

	std::string actual_file_data;
	ASSERT_TRUE(base::ReadFileToString(TestDir().Append(kTestFilename),
	&actual_file_data));
	ASSERT_EQ(kTestDataOne + kTestDataTwo + kTestDataThree, actual_file_data);
	}

	// Verifies that LocalFileOperations will write to a file named "file (1).txt"
	// if "file.txt" already exists, and "file (2).txt" after that.
	TEST_F(LocalFileOperationsTest, RenamesFileIfExists) {
	WriteFile(kTestFilename, base::queue<std::string>({kTestDataOne}),
	true /* close */);
	task_environment_.RunUntilIdle();
	EXPECT_TRUE(operation_completed_);

	WriteFile(kTestFilename, base::queue<std::string>({kTestDataTwo}),
	true /* close */);
	task_environment_.RunUntilIdle();
	EXPECT_TRUE(operation_completed_);

	WriteFile(kTestFilename, base::queue<std::string>({kTestDataThree}),
	true /* close */);
	task_environment_.RunUntilIdle();
	EXPECT_TRUE(operation_completed_);

	std::string actual_file_data_one;
	EXPECT_TRUE(base::ReadFileToString(TestDir().Append(kTestFilename),
	&actual_file_data_one));
	EXPECT_EQ(kTestDataOne, actual_file_data_one);
	std::string actual_file_data_two;
	EXPECT_TRUE(base::ReadFileToString(TestDir().Append(kTestFilenameSecondary),
	&actual_file_data_two));
	EXPECT_EQ(kTestDataTwo, actual_file_data_two);
	std::string actual_file_data_three;
	EXPECT_TRUE(base::ReadFileToString(TestDir().Append(kTestFilenameTertiary),
	&actual_file_data_three));
	EXPECT_EQ(kTestDataThree, actual_file_data_three);
	}

	// Verifies that dropping early deletes the temporary file.
	TEST_F(LocalFileOperationsTest, DroppingDeletesTemp) {
	WriteFile(
	kTestFilename,
	base::queue<std::string>({kTestDataOne, kTestDataTwo, kTestDataThree}),
	false /* close */);
	task_environment_.RunUntilIdle();
	ASSERT_TRUE(operation_completed_);

	file_writer_.reset();
	task_environment_.RunUntilIdle();

	ASSERT_TRUE(base::IsDirectoryEmpty(TestDir()));
	}

	// Verifies that dropping works while an operation is pending.
	TEST_F(LocalFileOperationsTest, CancelsWhileOperationPending) {
	WriteFile(kTestFilename, base::queue<std::string>({kTestDataOne}),
	false /* close */);
	task_environment_.RunUntilIdle();
	ASSERT_TRUE(operation_completed_);

	file_writer_->WriteChunk(kTestDataTwo, base::DoNothing());
	file_writer_.reset();
	task_environment_.RunUntilIdle();

	ASSERT_TRUE(base::IsDirectoryEmpty(TestDir()));
	}

	// Verifies that a file can be successfully opened for reading.
	TEST_F(LocalFileOperationsTest, OpensReader) {
	base::FilePath path = TestDir().Append(kTestFilename);
	std::string contents = kTestDataOne + kTestDataTwo + kTestDataThree;
	ASSERT_EQ(static_cast<int>(contents.size()),
	base::WriteFile(path, contents.data(), contents.size()));

	std::unique_ptr<FileOperations::Reader> reader =
	file_operations_->CreateReader();

	FakeFileChooser::SetResult(path);
	base::Optional<FileOperations::Reader::OpenResult> open_result;
	ASSERT_EQ(FileOperations::kCreated, reader->state());
	reader->Open(BindLambda([&](FileOperations::Reader::OpenResult result) {
	open_result = std::move(result);
	}));
	ASSERT_EQ(FileOperations::kBusy, reader->state());
	task_environment_.RunUntilIdle();
	EXPECT_EQ(FileOperations::kReady, reader->state());
	ASSERT_TRUE(open_result);
	ASSERT_TRUE(*open_result);
	EXPECT_EQ(kTestFilename, reader->filename());
	EXPECT_EQ(contents.size(), reader->size());
	}

	// Verifies that a file can be successfully read in three chunks.
	TEST_F(LocalFileOperationsTest, ReadsThreeChunks) {
	base::FilePath path = TestDir().Append(kTestFilename);
	std::string contents = kTestDataOne + kTestDataTwo + kTestDataThree;
	ASSERT_EQ(static_cast<int>(contents.size()),
	base::WriteFile(path, contents.data(), contents.size()));

	std::unique_ptr<FileOperations::Reader> reader =
	file_operations_->CreateReader();

	FakeFileChooser::SetResult(path);
	base::Optional<FileOperations::Reader::OpenResult> open_result;
	reader->Open(BindLambda([&](FileOperations::Reader::OpenResult result) {
	open_result = std::move(result);
	}));
	task_environment_.RunUntilIdle();
	ASSERT_TRUE(open_result && *open_result);

	for (const auto& chunk : {kTestDataOne, kTestDataTwo, kTestDataThree}) {
	base::Optional<FileOperations::Reader::ReadResult> read_result;
	reader->ReadChunk(
	chunk.size(),
	BindLambda([&](FileOperations::Reader::ReadResult result) {
	read_result = std::move(result);
	}));
	ASSERT_EQ(FileOperations::kBusy, reader->state());
	task_environment_.RunUntilIdle();
	ASSERT_EQ(FileOperations::kReady, reader->state());
	ASSERT_TRUE(read_result);
	ASSERT_TRUE(*read_result);
	EXPECT_EQ(chunk, **read_result);
	}
	}

	// Verifies proper EOF handling.
	TEST_F(LocalFileOperationsTest, ReaderHandlesEof) {
	base::FilePath path = TestDir().Append(kTestFilename);
	std::string contents = kTestDataOne + kTestDataTwo + kTestDataThree;
	ASSERT_EQ(static_cast<int>(contents.size()),
	base::WriteFile(path, contents.data(), contents.size()));

	std::unique_ptr<FileOperations::Reader> reader =
	file_operations_->CreateReader();

	FakeFileChooser::SetResult(path);
	base::Optional<FileOperations::Reader::OpenResult> open_result;
	reader->Open(BindLambda([&](FileOperations::Reader::OpenResult result) {
	open_result = std::move(result);
	}));
	task_environment_.RunUntilIdle();
	ASSERT_TRUE(open_result && *open_result);

	base::Optional<FileOperations::Reader::ReadResult> read_result;
	reader->ReadChunk(
	contents.size() + 5, // Attempt to read more than is in file.
	BindLambda([&](FileOperations::Reader::ReadResult result) {
	read_result = std::move(result);
	}));
	task_environment_.RunUntilIdle();
	ASSERT_EQ(FileOperations::kReady, reader->state());
	ASSERT_TRUE(read_result && *read_result);
	EXPECT_EQ(contents, **read_result);

	read_result.reset();
	reader->ReadChunk(5,
	BindLambda([&](FileOperations::Reader::ReadResult result) {
	read_result = std::move(result);
	}));
	task_environment_.RunUntilIdle();
	EXPECT_EQ(FileOperations::kComplete, reader->state());
	ASSERT_TRUE(read_result && *read_result);
	EXPECT_EQ(std::size_t{0}, (*read_result)->size());
	}

	// Verifies cancellation is propagated.
	TEST_F(LocalFileOperationsTest, ReaderCancels) {
	std::unique_ptr<FileOperations::Reader> reader =
	file_operations_->CreateReader();

	FakeFileChooser::SetResult(protocol::MakeFileTransferError(
	FROM_HERE, protocol::FileTransfer_Error_Type_CANCELED));
	base::Optional<FileOperations::Reader::OpenResult> open_result;
	reader->Open(BindLambda([&](FileOperations::Reader::OpenResult result) {
	open_result = std::move(result);
	}));
	task_environment_.RunUntilIdle();
	EXPECT_EQ(FileOperations::kFailed, reader->state());
	ASSERT_TRUE(open_result);
	ASSERT_FALSE(*open_result);
	EXPECT_EQ(protocol::FileTransfer_Error_Type_CANCELED,
	open_result->error().type());
	}

	// Verifies failure when file doesn't exist.
	TEST_F(LocalFileOperationsTest, FileNotFound) {
	std::unique_ptr<FileOperations::Reader> reader =
	file_operations_->CreateReader();

	// Currently non-existent file.
	FakeFileChooser::SetResult(TestDir().Append(kTestFilename));
	base::Optional<FileOperations::Reader::OpenResult> open_result;
	reader->Open(BindLambda([&](FileOperations::Reader::OpenResult result) {
	open_result = std::move(result);
	}));
	task_environment_.RunUntilIdle();
	EXPECT_EQ(FileOperations::kFailed, reader->state());
	ASSERT_TRUE(open_result);
	ASSERT_FALSE(*open_result);
	}

	} // namespace remoting