mandoline: Fork the files service from the mojo repository.

components/filesystem/file_impl_unittest.cc

+// Copyright 2015 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 <vector>
+
+#include "components/filesystem/files_test_base.h"
+#include "mojo/public/cpp/bindings/interface_request.h"
+#include "mojo/public/cpp/bindings/type_converter.h"
+
+namespace mojo {
+namespace files {
+namespace {
+
+using FileImplTest = FilesTestBase;
+
+TEST_F(FileImplTest, CreateWriteCloseRenameOpenRead) {
+  DirectoryPtr directory;
+  GetTemporaryRoot(&directory);
+  Error error;
+
+  {
+    // Create my_file.
+    FilePtr file;
+    error = ERROR_INTERNAL;
+    directory->OpenFile("my_file", GetProxy(&file),
+                        kOpenFlagWrite | kOpenFlagCreate, Capture(&error));
+    ASSERT_TRUE(directory.WaitForIncomingMethodCall());
+    EXPECT_EQ(ERROR_OK, error);
+
+    // Write to it.
+    std::vector<uint8_t> bytes_to_write;
+    bytes_to_write.push_back(static_cast<uint8_t>('h'));
+    bytes_to_write.push_back(static_cast<uint8_t>('e'));
+    bytes_to_write.push_back(static_cast<uint8_t>('l'));
+    bytes_to_write.push_back(static_cast<uint8_t>('l'));
+    bytes_to_write.push_back(static_cast<uint8_t>('o'));
+    error = ERROR_INTERNAL;
+    uint32_t num_bytes_written = 0;
+    file->Write(Array<uint8_t>::From(bytes_to_write), 0, WHENCE_FROM_CURRENT,
+                Capture(&error, &num_bytes_written));
+    ASSERT_TRUE(file.WaitForIncomingMethodCall());
+    EXPECT_EQ(ERROR_OK, error);
+    EXPECT_EQ(bytes_to_write.size(), num_bytes_written);
+
+    // Close it.
+    error = ERROR_INTERNAL;
+    file->Close(Capture(&error));
+    ASSERT_TRUE(file.WaitForIncomingMethodCall());
+    EXPECT_EQ(ERROR_OK, error);
+  }
+
+  // Rename it.
+  error = ERROR_INTERNAL;
+  directory->Rename("my_file", "your_file", Capture(&error));
+  ASSERT_TRUE(directory.WaitForIncomingMethodCall());
+  EXPECT_EQ(ERROR_OK, error);
+
+  {
+    // Open my_file again.
+    FilePtr file;
+    error = ERROR_INTERNAL;
+    directory->OpenFile("your_file", GetProxy(&file), kOpenFlagRead,
+                        Capture(&error));
+    ASSERT_TRUE(directory.WaitForIncomingMethodCall());
+    EXPECT_EQ(ERROR_OK, error);
+
+    // Read from it.
+    Array<uint8_t> bytes_read;
+    error = ERROR_INTERNAL;
+    file->Read(3, 1, WHENCE_FROM_START, Capture(&error, &bytes_read));
+    ASSERT_TRUE(file.WaitForIncomingMethodCall());
+    EXPECT_EQ(ERROR_OK, error);
+    ASSERT_EQ(3u, bytes_read.size());
+    EXPECT_EQ(static_cast<uint8_t>('e'), bytes_read[0]);
+    EXPECT_EQ(static_cast<uint8_t>('l'), bytes_read[1]);
+    EXPECT_EQ(static_cast<uint8_t>('l'), bytes_read[2]);
+  }
+
+  // TODO(vtl): Test read/write offset options.
+}
+
+TEST_F(FileImplTest, CantWriteInReadMode) {
+  DirectoryPtr directory;
+  GetTemporaryRoot(&directory);
+  Error error;
+
+  std::vector<uint8_t> bytes_to_write;
+  bytes_to_write.push_back(static_cast<uint8_t>('h'));
+  bytes_to_write.push_back(static_cast<uint8_t>('e'));
+  bytes_to_write.push_back(static_cast<uint8_t>('l'));
+  bytes_to_write.push_back(static_cast<uint8_t>('l'));
+  bytes_to_write.push_back(static_cast<uint8_t>('o'));
+
+  {
+    // Create my_file.
+    FilePtr file;
+    error = ERROR_INTERNAL;
+    directory->OpenFile("my_file", GetProxy(&file),
+                        kOpenFlagWrite | kOpenFlagCreate, Capture(&error));
+    ASSERT_TRUE(directory.WaitForIncomingMethodCall());
+    EXPECT_EQ(ERROR_OK, error);
+
+    // Write to it.
+    error = ERROR_INTERNAL;
+    uint32_t num_bytes_written = 0;
+    file->Write(Array<uint8_t>::From(bytes_to_write), 0, WHENCE_FROM_CURRENT,
+                Capture(&error, &num_bytes_written));
+    ASSERT_TRUE(file.WaitForIncomingMethodCall());
+    EXPECT_EQ(ERROR_OK, error);
+    EXPECT_EQ(bytes_to_write.size(), num_bytes_written);
+
+    // Close it.
+    error = ERROR_INTERNAL;
+    file->Close(Capture(&error));
+    ASSERT_TRUE(file.WaitForIncomingMethodCall());
+    EXPECT_EQ(ERROR_OK, error);
+  }
+
+  {
+    // Open my_file again, this time with read only mode.
+    FilePtr file;
+    error = ERROR_INTERNAL;
+    directory->OpenFile("my_file", GetProxy(&file), kOpenFlagRead,
+                        Capture(&error));
+    ASSERT_TRUE(directory.WaitForIncomingMethodCall());
+    EXPECT_EQ(ERROR_OK, error);
+
+    // Try to write in read mode; it should fail.
+    error = ERROR_INTERNAL;
+    uint32_t num_bytes_written = 0;
+    file->Write(Array<uint8_t>::From(bytes_to_write), 0, WHENCE_FROM_CURRENT,
+                Capture(&error, &num_bytes_written));
+    ASSERT_TRUE(file.WaitForIncomingMethodCall());
+    EXPECT_EQ(ERROR_UNKNOWN, error);
+    EXPECT_EQ(0u, num_bytes_written);
+
+    // Close it.
+    error = ERROR_INTERNAL;
+    file->Close(Capture(&error));
+    ASSERT_TRUE(file.WaitForIncomingMethodCall());
+    EXPECT_EQ(ERROR_OK, error);
+  }
+}
+
+TEST_F(FileImplTest, OpenExclusive) {
+  DirectoryPtr directory;
+  GetTemporaryRoot(&directory);
+  Error error;
+
+  {
+    // Create my_file.
+    FilePtr file;
+    error = ERROR_INTERNAL;
+    directory->OpenFile("temp_file", GetProxy(&file),
+                        kOpenFlagWrite | kOpenFlagCreate |kOpenFlagExclusive,
+                        Capture(&error));
+    ASSERT_TRUE(directory.WaitForIncomingMethodCall());
+    EXPECT_EQ(ERROR_OK, error);
+
+    // Close it.
+    error = ERROR_INTERNAL;
+    file->Close(Capture(&error));
+    ASSERT_TRUE(file.WaitForIncomingMethodCall());
+    EXPECT_EQ(ERROR_OK, error);
+  }
+
+  {
+    // Try to open my_file again in exclusive mode; it should fail.
+    FilePtr file;
+    error = ERROR_INTERNAL;
+    directory->OpenFile("temp_file", GetProxy(&file),
+                        kOpenFlagWrite | kOpenFlagCreate | kOpenFlagExclusive,
+                        Capture(&error));
+    ASSERT_TRUE(directory.WaitForIncomingMethodCall());
+    EXPECT_EQ(ERROR_UNKNOWN, error);
+  }
+}
+
+TEST_F(FileImplTest, OpenInAppendMode) {
+  DirectoryPtr directory;
+  GetTemporaryRoot(&directory);
+  Error error;
+
+  {
+    // Create my_file.
+    FilePtr file;
+    error = ERROR_INTERNAL;
+    directory->OpenFile("my_file", GetProxy(&file),
+                        kOpenFlagWrite | kOpenFlagCreate, Capture(&error));
+    ASSERT_TRUE(directory.WaitForIncomingMethodCall());
+    EXPECT_EQ(ERROR_OK, error);
+
+    // Write to it.
+    std::vector<uint8_t> bytes_to_write;
+    bytes_to_write.push_back(static_cast<uint8_t>('h'));
+    bytes_to_write.push_back(static_cast<uint8_t>('e'));
+    bytes_to_write.push_back(static_cast<uint8_t>('l'));
+    bytes_to_write.push_back(static_cast<uint8_t>('l'));
+    bytes_to_write.push_back(static_cast<uint8_t>('o'));
+    error = ERROR_INTERNAL;
+    uint32_t num_bytes_written = 0;
+    file->Write(Array<uint8_t>::From(bytes_to_write), 0, WHENCE_FROM_CURRENT,
+                Capture(&error, &num_bytes_written));
+    ASSERT_TRUE(file.WaitForIncomingMethodCall());
+    EXPECT_EQ(ERROR_OK, error);
+    EXPECT_EQ(bytes_to_write.size(), num_bytes_written);
+
+    // Close it.
+    error = ERROR_INTERNAL;
+    file->Close(Capture(&error));
+    ASSERT_TRUE(file.WaitForIncomingMethodCall());
+    EXPECT_EQ(ERROR_OK, error);
+  }
+
+  {
+    // Append to my_file.
+    FilePtr file;
+    error = ERROR_INTERNAL;
+    directory->OpenFile("my_file", GetProxy(&file),
+                        kOpenFlagWrite | kOpenFlagAppend, Capture(&error));
+    ASSERT_TRUE(directory.WaitForIncomingMethodCall());
+    EXPECT_EQ(ERROR_OK, error);
+
+    // Write to it.
+    std::vector<uint8_t> bytes_to_write;
+    bytes_to_write.push_back(static_cast<uint8_t>('g'));
+    bytes_to_write.push_back(static_cast<uint8_t>('o'));
+    bytes_to_write.push_back(static_cast<uint8_t>('o'));
+    bytes_to_write.push_back(static_cast<uint8_t>('d'));
+    bytes_to_write.push_back(static_cast<uint8_t>('b'));
+    bytes_to_write.push_back(static_cast<uint8_t>('y'));
+    bytes_to_write.push_back(static_cast<uint8_t>('e'));
+    error = ERROR_INTERNAL;
+    uint32_t num_bytes_written = 0;
+    file->Write(Array<uint8_t>::From(bytes_to_write), 0, WHENCE_FROM_CURRENT,
+                Capture(&error, &num_bytes_written));
+    ASSERT_TRUE(file.WaitForIncomingMethodCall());
+    EXPECT_EQ(ERROR_OK, error);
+    EXPECT_EQ(bytes_to_write.size(), num_bytes_written);
+
+    // Close it.
+    error = ERROR_INTERNAL;
+    file->Close(Capture(&error));
+    ASSERT_TRUE(file.WaitForIncomingMethodCall());
+    EXPECT_EQ(ERROR_OK, error);
+  }
+
+  {
+    // Open my_file again.
+    FilePtr file;
+    error = ERROR_INTERNAL;
+    directory->OpenFile("my_file", GetProxy(&file), kOpenFlagRead,
+                        Capture(&error));
+    ASSERT_TRUE(directory.WaitForIncomingMethodCall());
+    EXPECT_EQ(ERROR_OK, error);
+
+    // Read from it.
+    Array<uint8_t> bytes_read;
+    error = ERROR_INTERNAL;
+    file->Read(12, 0, WHENCE_FROM_START, Capture(&error, &bytes_read));
+    ASSERT_TRUE(file.WaitForIncomingMethodCall());
+    EXPECT_EQ(ERROR_OK, error);
+    ASSERT_EQ(12u, bytes_read.size());
+    EXPECT_EQ(static_cast<uint8_t>('l'), bytes_read[3]);
+    EXPECT_EQ(static_cast<uint8_t>('o'), bytes_read[4]);
+    EXPECT_EQ(static_cast<uint8_t>('g'), bytes_read[5]);
+    EXPECT_EQ(static_cast<uint8_t>('o'), bytes_read[6]);
+  }
+}
+
+TEST_F(FileImplTest, OpenInTruncateMode) {
+  DirectoryPtr directory;
+  GetTemporaryRoot(&directory);
+  Error error;
+
+  {
+    // Create my_file.
+    FilePtr file;
+    error = ERROR_INTERNAL;
+    directory->OpenFile("my_file", GetProxy(&file),
+                        kOpenFlagWrite | kOpenFlagCreate, Capture(&error));
+    ASSERT_TRUE(directory.WaitForIncomingMethodCall());
+    EXPECT_EQ(ERROR_OK, error);
+
+    // Write to it.
+    std::vector<uint8_t> bytes_to_write;
+    bytes_to_write.push_back(static_cast<uint8_t>('h'));
+    bytes_to_write.push_back(static_cast<uint8_t>('e'));
+    bytes_to_write.push_back(static_cast<uint8_t>('l'));
+    bytes_to_write.push_back(static_cast<uint8_t>('l'));
+    bytes_to_write.push_back(static_cast<uint8_t>('o'));
+    error = ERROR_INTERNAL;
+    uint32_t num_bytes_written = 0;
+    file->Write(Array<uint8_t>::From(bytes_to_write), 0, WHENCE_FROM_CURRENT,
+                Capture(&error, &num_bytes_written));
+    ASSERT_TRUE(file.WaitForIncomingMethodCall());
+    EXPECT_EQ(ERROR_OK, error);
+    EXPECT_EQ(bytes_to_write.size(), num_bytes_written);
+
+    // Close it.
+    error = ERROR_INTERNAL;
+    file->Close(Capture(&error));
+    ASSERT_TRUE(file.WaitForIncomingMethodCall());
+    EXPECT_EQ(ERROR_OK, error);
+  }
+
+  {
+    // Append to my_file.
+    FilePtr file;
+    error = ERROR_INTERNAL;
+    directory->OpenFile("my_file", GetProxy(&file),
+                        kOpenFlagWrite | kOpenFlagTruncate, Capture(&error));
+    ASSERT_TRUE(directory.WaitForIncomingMethodCall());
+    EXPECT_EQ(ERROR_OK, error);
+
+    // Write to it.
+    std::vector<uint8_t> bytes_to_write;
+    bytes_to_write.push_back(static_cast<uint8_t>('g'));
+    bytes_to_write.push_back(static_cast<uint8_t>('o'));
+    bytes_to_write.push_back(static_cast<uint8_t>('o'));
+    bytes_to_write.push_back(static_cast<uint8_t>('d'));
+    bytes_to_write.push_back(static_cast<uint8_t>('b'));
+    bytes_to_write.push_back(static_cast<uint8_t>('y'));
+    bytes_to_write.push_back(static_cast<uint8_t>('e'));
+    error = ERROR_INTERNAL;
+    uint32_t num_bytes_written = 0;
+    file->Write(Array<uint8_t>::From(bytes_to_write), 0, WHENCE_FROM_CURRENT,
+                Capture(&error, &num_bytes_written));
+    ASSERT_TRUE(file.WaitForIncomingMethodCall());
+    EXPECT_EQ(ERROR_OK, error);
+    EXPECT_EQ(bytes_to_write.size(), num_bytes_written);
+
+    // Close it.
+    error = ERROR_INTERNAL;
+    file->Close(Capture(&error));
+    ASSERT_TRUE(file.WaitForIncomingMethodCall());
+    EXPECT_EQ(ERROR_OK, error);
+  }
+
+  {
+    // Open my_file again.
+    FilePtr file;
+    error = ERROR_INTERNAL;
+    directory->OpenFile("my_file", GetProxy(&file), kOpenFlagRead,
+                        Capture(&error));
+    ASSERT_TRUE(directory.WaitForIncomingMethodCall());
+    EXPECT_EQ(ERROR_OK, error);
+
+    // Read from it.
+    Array<uint8_t> bytes_read;
+    error = ERROR_INTERNAL;
+    file->Read(7, 0, WHENCE_FROM_START, Capture(&error, &bytes_read));
+    ASSERT_TRUE(file.WaitForIncomingMethodCall());
+    EXPECT_EQ(ERROR_OK, error);
+    ASSERT_EQ(7u, bytes_read.size());
+    EXPECT_EQ(static_cast<uint8_t>('g'), bytes_read[0]);
+    EXPECT_EQ(static_cast<uint8_t>('o'), bytes_read[1]);
+    EXPECT_EQ(static_cast<uint8_t>('o'), bytes_read[2]);
+    EXPECT_EQ(static_cast<uint8_t>('d'), bytes_read[3]);
+  }
+}
+
+// Note: Ignore nanoseconds, since it may not always be supported. We expect at
+// least second-resolution support though.
+TEST_F(FileImplTest, StatTouch) {
+  DirectoryPtr directory;
+  GetTemporaryRoot(&directory);
+  Error error;
+
+  // Create my_file.
+  FilePtr file;
+  error = ERROR_INTERNAL;
+  directory->OpenFile("my_file", GetProxy(&file),
+                      kOpenFlagWrite | kOpenFlagCreate, Capture(&error));
+  ASSERT_TRUE(directory.WaitForIncomingMethodCall());
+  EXPECT_EQ(ERROR_OK, error);
+
+  // Stat it.
+  error = ERROR_INTERNAL;
+  FileInformationPtr file_info;
+  file->Stat(Capture(&error, &file_info));
+  ASSERT_TRUE(file.WaitForIncomingMethodCall());
+  EXPECT_EQ(ERROR_OK, error);
+  ASSERT_FALSE(file_info.is_null());
+  EXPECT_EQ(FILE_TYPE_REGULAR_FILE, file_info->type);
+  EXPECT_EQ(0, file_info->size);
+  ASSERT_FALSE(file_info->atime.is_null());
+  EXPECT_GT(file_info->atime->seconds, 0);  // Expect that it's not 1970-01-01.
+  ASSERT_FALSE(file_info->mtime.is_null());
+  EXPECT_GT(file_info->mtime->seconds, 0);
+  int64_t first_mtime = file_info->mtime->seconds;
+
+  // Touch only the atime.
+  error = ERROR_INTERNAL;
+  TimespecOrNowPtr t(TimespecOrNow::New());
+  t->now = false;
+  t->timespec = Timespec::New();
+  const int64_t kPartyTime1 = 1234567890;  // Party like it's 2009-02-13.
+  t->timespec->seconds = kPartyTime1;
+  file->Touch(t.Pass(), nullptr, Capture(&error));
+  ASSERT_TRUE(file.WaitForIncomingMethodCall());
+  EXPECT_EQ(ERROR_OK, error);
+
+  // Stat again.
+  error = ERROR_INTERNAL;
+  file_info.reset();
+  file->Stat(Capture(&error, &file_info));
+  ASSERT_TRUE(file.WaitForIncomingMethodCall());
+  EXPECT_EQ(ERROR_OK, error);
+  ASSERT_FALSE(file_info.is_null());
+  ASSERT_FALSE(file_info->atime.is_null());
+  EXPECT_EQ(kPartyTime1, file_info->atime->seconds);
+  ASSERT_FALSE(file_info->mtime.is_null());
+  EXPECT_EQ(first_mtime, file_info->mtime->seconds);
+
+  // Touch only the mtime.
+  t = TimespecOrNow::New();
+  t->now = false;
+  t->timespec = Timespec::New();
+  const int64_t kPartyTime2 = 1425059525;  // No time like the present.
+  t->timespec->seconds = kPartyTime2;
+  file->Touch(nullptr, t.Pass(), Capture(&error));
+  ASSERT_TRUE(file.WaitForIncomingMethodCall());
+  EXPECT_EQ(ERROR_OK, error);
+
+  // Stat again.
+  error = ERROR_INTERNAL;
+  file_info.reset();
+  file->Stat(Capture(&error, &file_info));
+  ASSERT_TRUE(file.WaitForIncomingMethodCall());
+  EXPECT_EQ(ERROR_OK, error);
+  ASSERT_FALSE(file_info.is_null());
+  ASSERT_FALSE(file_info->atime.is_null());
+  EXPECT_EQ(kPartyTime1, file_info->atime->seconds);
+  ASSERT_FALSE(file_info->mtime.is_null());
+  EXPECT_EQ(kPartyTime2, file_info->mtime->seconds);
+
+  // TODO(vtl): Also test non-zero file size.
+  // TODO(vtl): Also test Touch() "now" options.
+  // TODO(vtl): Also test touching both atime and mtime.
+}
+
+TEST_F(FileImplTest, TellSeek) {
+  DirectoryPtr directory;
+  GetTemporaryRoot(&directory);
+  Error error;
+
+  // Create my_file.
+  FilePtr file;
+  error = ERROR_INTERNAL;
+  directory->OpenFile("my_file", GetProxy(&file),
+                      kOpenFlagWrite | kOpenFlagCreate, Capture(&error));
+  ASSERT_TRUE(directory.WaitForIncomingMethodCall());
+  EXPECT_EQ(ERROR_OK, error);
+
+  // Write to it.
+  std::vector<uint8_t> bytes_to_write(1000, '!');
+  error = ERROR_INTERNAL;
+  uint32_t num_bytes_written = 0;
+  file->Write(Array<uint8_t>::From(bytes_to_write), 0, WHENCE_FROM_CURRENT,
+              Capture(&error, &num_bytes_written));
+  ASSERT_TRUE(file.WaitForIncomingMethodCall());
+  EXPECT_EQ(ERROR_OK, error);
+  EXPECT_EQ(bytes_to_write.size(), num_bytes_written);
+  const int size = static_cast<int>(num_bytes_written);
+
+  // Tell.
+  error = ERROR_INTERNAL;
+  int64_t position = -1;
+  file->Tell(Capture(&error, &position));
+  ASSERT_TRUE(file.WaitForIncomingMethodCall());
+  // Should be at the end.
+  EXPECT_EQ(ERROR_OK, error);
+  EXPECT_EQ(size, position);
+
+  // Seek back 100.
+  error = ERROR_INTERNAL;
+  position = -1;
+  file->Seek(-100, WHENCE_FROM_CURRENT, Capture(&error, &position));
+  ASSERT_TRUE(file.WaitForIncomingMethodCall());
+  EXPECT_EQ(ERROR_OK, error);
+  EXPECT_EQ(size - 100, position);
+
+  // Tell.
+  error = ERROR_INTERNAL;
+  position = -1;
+  file->Tell(Capture(&error, &position));
+  ASSERT_TRUE(file.WaitForIncomingMethodCall());
+  EXPECT_EQ(ERROR_OK, error);
+  EXPECT_EQ(size - 100, position);
+
+  // Seek to 123 from start.
+  error = ERROR_INTERNAL;
+  position = -1;
+  file->Seek(123, WHENCE_FROM_START, Capture(&error, &position));
+  ASSERT_TRUE(file.WaitForIncomingMethodCall());
+  EXPECT_EQ(ERROR_OK, error);
+  EXPECT_EQ(123, position);
+
+  // Tell.
+  error = ERROR_INTERNAL;
+  position = -1;
+  file->Tell(Capture(&error, &position));
+  ASSERT_TRUE(file.WaitForIncomingMethodCall());
+  EXPECT_EQ(ERROR_OK, error);
+  EXPECT_EQ(123, position);
+
+  // Seek to 123 back from end.
+  error = ERROR_INTERNAL;
+  position = -1;
+  file->Seek(-123, WHENCE_FROM_END, Capture(&error, &position));
+  ASSERT_TRUE(file.WaitForIncomingMethodCall());
+  EXPECT_EQ(ERROR_OK, error);
+  EXPECT_EQ(size - 123, position);
+
+  // Tell.
+  error = ERROR_INTERNAL;
+  position = -1;
+  file->Tell(Capture(&error, &position));
+  ASSERT_TRUE(file.WaitForIncomingMethodCall());
+  EXPECT_EQ(ERROR_OK, error);
+  EXPECT_EQ(size - 123, position);
+
+  // TODO(vtl): Check that seeking actually affects reading/writing.
+  // TODO(vtl): Check that seeking can extend the file?
+}
+
+TEST_F(FileImplTest, Dup) {
+  DirectoryPtr directory;
+  GetTemporaryRoot(&directory);
+  Error error;
+
+  // Create my_file.
+  FilePtr file1;
+  error = ERROR_INTERNAL;
+  directory->OpenFile("my_file", GetProxy(&file1),
+                      kOpenFlagRead | kOpenFlagWrite | kOpenFlagCreate,
+                      Capture(&error));
+  ASSERT_TRUE(directory.WaitForIncomingMethodCall());
+  EXPECT_EQ(ERROR_OK, error);
+
+  // Write to it.
+  std::vector<uint8_t> bytes_to_write;
+  bytes_to_write.push_back(static_cast<uint8_t>('h'));
+  bytes_to_write.push_back(static_cast<uint8_t>('e'));
+  bytes_to_write.push_back(static_cast<uint8_t>('l'));
+  bytes_to_write.push_back(static_cast<uint8_t>('l'));
+  bytes_to_write.push_back(static_cast<uint8_t>('o'));
+  error = ERROR_INTERNAL;
+  uint32_t num_bytes_written = 0;
+  file1->Write(Array<uint8_t>::From(bytes_to_write), 0, WHENCE_FROM_CURRENT,
+               Capture(&error, &num_bytes_written));
+  ASSERT_TRUE(file1.WaitForIncomingMethodCall());
+  EXPECT_EQ(ERROR_OK, error);
+  EXPECT_EQ(bytes_to_write.size(), num_bytes_written);
+  const int end_hello_pos = static_cast<int>(num_bytes_written);
+
+  // Dup it.
+  FilePtr file2;
+  error = ERROR_INTERNAL;
+  file1->Dup(GetProxy(&file2), Capture(&error));
+  ASSERT_TRUE(file1.WaitForIncomingMethodCall());
+  EXPECT_EQ(ERROR_OK, error);
+
+  // |file2| should have the same position.
+  error = ERROR_INTERNAL;
+  int64_t position = -1;
+  file2->Tell(Capture(&error, &position));
+  ASSERT_TRUE(file2.WaitForIncomingMethodCall());
+  EXPECT_EQ(ERROR_OK, error);
+  EXPECT_EQ(end_hello_pos, position);
+
+  // Write using |file2|.
+  std::vector<uint8_t> more_bytes_to_write;
+  more_bytes_to_write.push_back(static_cast<uint8_t>('w'));
+  more_bytes_to_write.push_back(static_cast<uint8_t>('o'));
+  more_bytes_to_write.push_back(static_cast<uint8_t>('r'));
+  more_bytes_to_write.push_back(static_cast<uint8_t>('l'));
+  more_bytes_to_write.push_back(static_cast<uint8_t>('d'));
+  error = ERROR_INTERNAL;
+  num_bytes_written = 0;
+  file2->Write(Array<uint8_t>::From(more_bytes_to_write), 0,
+               WHENCE_FROM_CURRENT, Capture(&error, &num_bytes_written));
+  ASSERT_TRUE(file2.WaitForIncomingMethodCall());
+  EXPECT_EQ(ERROR_OK, error);
+  EXPECT_EQ(more_bytes_to_write.size(), num_bytes_written);
+  const int end_world_pos = end_hello_pos + static_cast<int>(num_bytes_written);
+
+  // |file1| should have the same position.
+  error = ERROR_INTERNAL;
+  position = -1;
+  file1->Tell(Capture(&error, &position));
+  ASSERT_TRUE(file1.WaitForIncomingMethodCall());
+  EXPECT_EQ(ERROR_OK, error);
+  EXPECT_EQ(end_world_pos, position);
+
+  // Close |file1|.
+  error = ERROR_INTERNAL;
+  file1->Close(Capture(&error));
+  ASSERT_TRUE(file1.WaitForIncomingMethodCall());
+  EXPECT_EQ(ERROR_OK, error);
+
+  // Read everything using |file2|.
+  Array<uint8_t> bytes_read;
+  error = ERROR_INTERNAL;
+  file2->Read(1000, 0, WHENCE_FROM_START, Capture(&error, &bytes_read));
+  ASSERT_TRUE(file2.WaitForIncomingMethodCall());
+  EXPECT_EQ(ERROR_OK, error);
+  ASSERT_EQ(static_cast<size_t>(end_world_pos), bytes_read.size());
+  // Just check the first and last bytes.
+  EXPECT_EQ(static_cast<uint8_t>('h'), bytes_read[0]);
+  EXPECT_EQ(static_cast<uint8_t>('d'), bytes_read[end_world_pos - 1]);
+
+  // TODO(vtl): Test that |file2| has the same open options as |file1|.
+}
+
+TEST_F(FileImplTest, Truncate) {
+  const uint32_t kInitialSize = 1000;
+  const uint32_t kTruncatedSize = 654;
+
+  DirectoryPtr directory;
+  GetTemporaryRoot(&directory);
+  Error error;
+
+  // Create my_file.
+  FilePtr file;
+  error = ERROR_INTERNAL;
+  directory->OpenFile("my_file", GetProxy(&file),
+                      kOpenFlagWrite | kOpenFlagCreate, Capture(&error));
+  ASSERT_TRUE(directory.WaitForIncomingMethodCall());
+  EXPECT_EQ(ERROR_OK, error);
+
+  // Write to it.
+  std::vector<uint8_t> bytes_to_write(kInitialSize, '!');
+  error = ERROR_INTERNAL;
+  uint32_t num_bytes_written = 0;
+  file->Write(Array<uint8_t>::From(bytes_to_write), 0, WHENCE_FROM_CURRENT,
+              Capture(&error, &num_bytes_written));
+  ASSERT_TRUE(file.WaitForIncomingMethodCall());
+  EXPECT_EQ(ERROR_OK, error);
+  EXPECT_EQ(kInitialSize, num_bytes_written);
+
+  // Stat it.
+  error = ERROR_INTERNAL;
+  FileInformationPtr file_info;
+  file->Stat(Capture(&error, &file_info));
+  ASSERT_TRUE(file.WaitForIncomingMethodCall());
+  EXPECT_EQ(ERROR_OK, error);
+  ASSERT_FALSE(file_info.is_null());
+  EXPECT_EQ(kInitialSize, file_info->size);
+
+  // Truncate it.
+  error = ERROR_INTERNAL;
+  file->Truncate(kTruncatedSize, Capture(&error));
+  ASSERT_TRUE(file.WaitForIncomingMethodCall());
+  EXPECT_EQ(ERROR_OK, error);
+
+  // Stat again.
+  error = ERROR_INTERNAL;
+  file_info.reset();
+  file->Stat(Capture(&error, &file_info));
+  ASSERT_TRUE(file.WaitForIncomingMethodCall());
+  EXPECT_EQ(ERROR_OK, error);
+  ASSERT_FALSE(file_info.is_null());
+  EXPECT_EQ(kTruncatedSize, file_info->size);
+}
+
+TEST_F(FileImplTest, Ioctl) {
+  DirectoryPtr directory;
+  GetTemporaryRoot(&directory);
+  Error error;
+
+  // Create my_file.
+  FilePtr file;
+  error = ERROR_INTERNAL;
+  directory->OpenFile("my_file", GetProxy(&file),
+                      kOpenFlagRead | kOpenFlagWrite | kOpenFlagCreate,
+                      Capture(&error));
+  ASSERT_TRUE(directory.WaitForIncomingMethodCall());
+  EXPECT_EQ(ERROR_OK, error);
+
+  // Normal files don't support any ioctls.
+  Array<uint32_t> out_values;
+  file->Ioctl(0, Array<uint32_t>(), Capture(&error, &out_values));
+  ASSERT_TRUE(file.WaitForIncomingMethodCall());
+  EXPECT_EQ(ERROR_UNAVAILABLE, error);
+  EXPECT_TRUE(out_values.is_null());
+}
+
+}  // namespace
+}  // namespace files
+}  // namespace mojo