[NaCl SDK] Expose Google Drive to nacl_io.

native_client_sdk/src/tests/nacl_io_test/googledrivefs_test.cc

Index: native_client_sdk/src/tests/nacl_io_test/googledrivefs_test.cc
diff --git a/native_client_sdk/src/tests/nacl_io_test/googledrivefs_test.cc b/native_client_sdk/src/tests/nacl_io_test/googledrivefs_test.cc
new file mode 100644
index 0000000000000000000000000000000000000000..07a1a88ab188e3d6ac94589a040b08d76d0754fe
--- /dev/null
+++ b/native_client_sdk/src/tests/nacl_io_test/googledrivefs_test.cc
@@ -0,0 +1,768 @@
+// 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 <errno.h>
+#include <fcntl.h>
+
+#include <set>
+#include <string>
+
+#include <gmock/gmock.h>
+
+#include "nacl_io/googledrivefs/googledrivefs.h"
+#include "nacl_io/kernel_handle.h"
+#include "nacl_io/osdirent.h"
+#include "nacl_io/pepper_interface_delegate.h"
+#include "sdk_util/scoped_ref.h"
+
+#include "fake_ppapi/fake_pepper_interface_googledrivefs.h"
+#include "fake_ppapi/fake_util.h"
+#include "mock_util.h"
+
+using namespace nacl_io;
+using namespace sdk_util;
+
+using ::testing::_;
+using ::testing::DoAll;
+using ::testing::Invoke;
+using ::testing::Return;
+
+namespace {
+
+class GoogleDriveFsForTesting : public GoogleDriveFs {
+ public:
+  GoogleDriveFsForTesting(const StringMap_t& string_map,
+                          PepperInterface* ppapi) {
+    FsInitArgs args;
+    args.string_map = string_map;
+    args.ppapi = ppapi;
+    Error error = Init(args);
+    EXPECT_EQ(0, error);
+  }
+};
+
+class GoogleDriveFsTest : public ::testing::Test {
+ public:
+  GoogleDriveFsTest();
+
+  virtual void SetUp() { map_["token"] = "some token value"; }
+
+ protected:
+  FakePepperInterfaceGoogleDriveFs ppapi_googledrivefs_;
+  PepperInterfaceDelegate ppapi_;
+  StringMap_t map_;
+};
+
+GoogleDriveFsTest::GoogleDriveFsTest()
+    : ppapi_(ppapi_googledrivefs_.GetInstance()) {
+  // Default delegation to the googledrivefs pepper interface.
+  ppapi_.SetCoreInterfaceDelegate(ppapi_googledrivefs_.GetCoreInterface());
+  ppapi_.SetURLLoaderInterfaceDelegate(
+      ppapi_googledrivefs_.GetURLLoaderInterface());
+  ppapi_.SetURLRequestInfoInterfaceDelegate(
+      ppapi_googledrivefs_.GetURLRequestInfoInterface());
+  ppapi_.SetURLResponseInfoInterfaceDelegate(
+      ppapi_googledrivefs_.GetURLResponseInfoInterface());
+  ppapi_.SetFileIoInterfaceDelegate(ppapi_googledrivefs_.GetFileIoInterface());
+  ppapi_.SetVarInterfaceDelegate(ppapi_googledrivefs_.GetVarInterface());
+}
+
+}  // namespace
+
+TEST_F(GoogleDriveFsTest, Mkdir) {
+  ScopedRef<GoogleDriveFsForTesting> fs(
+      new GoogleDriveFsForTesting(map_, &ppapi_));
+
+  //
+  // mkdir at the root should return EEXIST, not EACCES.
+  //
+  EXPECT_EQ(EEXIST, fs->Mkdir(Path("/"), 0644));
+
+  //
+  // mkdir on a directory that has not been existed.
+  //
+  Path path("/foo");
+
+  ASSERT_EQ(0, fs->Mkdir(path, 0644));
+
+  ScopedNode node;
+  ASSERT_EQ(0, fs->Open(path, O_RDONLY, &node));
+
+  EXPECT_TRUE(node->IsaDir());
+
+  //
+  // mkdir on a directory that has already been existed.
+  //
+  EXPECT_EQ(EEXIST, fs->Mkdir(path, 0644));
+
+  //
+  // mkdir on an existing file.
+  //
+  ScopedNode file_node;
+  Path file_path("/filename");
+  ASSERT_EQ(0, fs->Open(file_path, O_WRONLY | O_CREAT | O_TRUNC, &file_node));
+
+  EXPECT_EQ(EEXIST, fs->Mkdir(file_path, 0644));
+}
+
+TEST_F(GoogleDriveFsTest, Rmdir) {
+  ScopedRef<GoogleDriveFsForTesting> fs(
+      new GoogleDriveFsForTesting(map_, &ppapi_));
+  //
+  // rmdir at the root returns EEXIST, as returned in nacl_io_demo.
+  //
+  EXPECT_EQ(EEXIST, fs->Rmdir(Path("/")));
+
+  //
+  // rmdir on an existing dir.
+  //
+  Path dir_path("/dir");
+
+  ASSERT_EQ(0, fs->Mkdir(dir_path, 0644));
+  EXPECT_EQ(0, fs->Rmdir(dir_path));
+
+  //
+  // rmdir on a non-existing dir.
+  //
+  EXPECT_EQ(ENOENT, fs->Rmdir(dir_path));
+
+  //
+  // rmdir on an existing file.
+  //
+  ScopedNode file_node;
+  Path file_path("/filename");
+  ASSERT_EQ(0, fs->Open(file_path, O_RDWR | O_CREAT | O_TRUNC, &file_node));
+
+  ASSERT_EQ(ENOTDIR, fs->Rmdir(file_path));
+
+  //
+  // rmdir on an existing dir that has a file.
+  //
+  Path nonempty_dir_path("/nonempty_dir");
+  ASSERT_EQ(0, fs->Mkdir(nonempty_dir_path, 0644));
+
+  ScopedNode file_in_nonempty_dir_node;
+  Path file_in_nonempty_dir_path("/nonempty_dir/file");
+  ASSERT_EQ(0, fs->Open(file_in_nonempty_dir_path, O_RDWR | O_CREAT | O_TRUNC,
+                        &file_in_nonempty_dir_node));
+
+  EXPECT_EQ(ENOTEMPTY, fs->Rmdir(nonempty_dir_path));
+}
+
+TEST_F(GoogleDriveFsTest, OpenNonExistingFile) {
+  ScopedRef<GoogleDriveFsForTesting> fs(
+      new GoogleDriveFsForTesting(map_, &ppapi_));
+
+  //
+  // open a non-existing file in r mode.
+  //
+  Path nonexisting_file_path("/file");
+  ScopedNode nonexisting_file_node;
+  EXPECT_EQ(ENOENT,
+            fs->Open(nonexisting_file_path, O_RDONLY, &nonexisting_file_node));
+
+  //
+  // open a non-existing file in r+ mode.
+  //
+  EXPECT_EQ(ENOENT,
+            fs->Open(nonexisting_file_path, O_RDWR, &nonexisting_file_node));
+
+  //
+  // open a non-existing file in w mode.
+  //
+  Path nonexisting_file_w_mode_path("/nonexisting_file_w_mode");
+  ScopedNode nonexisting_file_w_mode_node;
+  EXPECT_EQ(0,
+            fs->Open(nonexisting_file_w_mode_path, O_WRONLY | O_CREAT | O_TRUNC,
+                     &nonexisting_file_w_mode_node));
+
+  //
+  // open a non-existing file in w+ mode.
+  //
+  Path nonexisting_file_w_plus_mode_path("/nonexisting_file_w_plus_mode");
+  ScopedNode nonexisting_file_w_plus_mode_node;
+  EXPECT_EQ(
+      0, fs->Open(nonexisting_file_w_plus_mode_path, O_RDWR | O_CREAT | O_TRUNC,
+                  &nonexisting_file_w_plus_mode_node));
+
+  //
+  // open a non-existing file in a mode.
+  //
+  Path nonexisting_file_a_mode_path("/nonexisting_file_a_mode");
+  ScopedNode nonexisting_file_a_mode_node;
+  EXPECT_EQ(
+      0, fs->Open(nonexisting_file_a_mode_path, O_WRONLY | O_CREAT | O_APPEND,
+                  &nonexisting_file_a_mode_node));
+
+  //
+  // open a non-existing file in a+ mode.
+  //
+  Path nonexisting_file_a_plus_mode_path("/nonexisting_file_a_plus_mode");
+  ScopedNode nonexisting_file_a_plus_mode_node;
+  EXPECT_EQ(0, fs->Open(nonexisting_file_a_plus_mode_path,
+                        O_RDWR | O_CREAT | O_APPEND,
+                        &nonexisting_file_a_plus_mode_node));
+}
+
+TEST_F(GoogleDriveFsTest, OpenExistingFile) {
+  ScopedRef<GoogleDriveFsForTesting> fs(
+      new GoogleDriveFsForTesting(map_, &ppapi_));
+
+  Path existing_file_path("/file");
+  ScopedNode existing_file_node;
+  EXPECT_EQ(0, fs->Open(existing_file_path, O_WRONLY | O_CREAT | O_TRUNC,
+                        &existing_file_node));
+
+  //
+  // open an existing file in r mode.
+  //
+  ScopedNode existing_file_r_mode_node;
+  EXPECT_EQ(0,
+            fs->Open(existing_file_path, O_RDONLY, &existing_file_r_mode_node));
+
+  //
+  // open an existing file in r+ mode.
+  //
+  ScopedNode existing_file_r_plus_mode_node;
+  EXPECT_EQ(
+      0, fs->Open(existing_file_path, O_RDWR, &existing_file_r_plus_mode_node));
+
+  //
+  // open an existing file in w mode.
+  //
+  ScopedNode existing_file_w_mode_node;
+  EXPECT_EQ(0, fs->Open(existing_file_path, O_WRONLY | O_CREAT | O_TRUNC,
+                        &existing_file_w_mode_node));
+
+  //
+  // open an existing file in w+ mode.
+  //
+  ScopedNode existing_file_w_plus_mode_node;
+  EXPECT_EQ(0, fs->Open(existing_file_path, O_RDWR | O_CREAT | O_TRUNC,
+                        &existing_file_w_plus_mode_node));
+
+  //
+  // open an existing file in a mode.
+  //
+  ScopedNode existing_file_a_mode_node;
+  EXPECT_EQ(0, fs->Open(existing_file_path, O_WRONLY | O_CREAT | O_APPEND,
+                        &existing_file_a_mode_node));
+
+  //
+  // open an existing file in a+ mode.
+  //
+  ScopedNode existing_file_a_plus_mode_node;
+  EXPECT_EQ(0, fs->Open(existing_file_path, O_RDWR | O_CREAT | O_APPEND,
+                        &existing_file_a_plus_mode_node));
+}
+
+TEST_F(GoogleDriveFsTest, OpenOtherCases) {
+  ScopedRef<GoogleDriveFsForTesting> fs(
+      new GoogleDriveFsForTesting(map_, &ppapi_));
+
+  //
+  // A file opened without O_TRUNC flag does not truncate data.
+  //
+  Path file_path("/file");
+  ScopedNode file_node;
+  EXPECT_EQ(0, fs->Open(file_path, O_WRONLY | O_CREAT | O_APPEND, &file_node));
+
+  // Write some data.
+  const char* contents = "contents";
+  int bytes_written;
+  EXPECT_EQ(0, file_node->Write(HandleAttr(), contents, strlen(contents),
+                                &bytes_written));
+  EXPECT_EQ(strlen(contents), bytes_written);
+
+  // Create again.
+  EXPECT_EQ(0, fs->Open(file_path, O_WRONLY | O_CREAT | O_APPEND, &file_node));
+
+  // Check that the file still has data.
+  off_t size;
+  EXPECT_EQ(0, file_node->GetSize(&size));
+  EXPECT_EQ(strlen(contents), size);
+
+  //
+  // A file opened with O_TRUNC flag truncates data.
+  //
+  // Create again.
+  EXPECT_EQ(0, fs->Open(file_path, O_WRONLY | O_CREAT | O_TRUNC, &file_node));
+
+  // File should be empty.
+  EXPECT_EQ(0, file_node->GetSize(&size));
+  EXPECT_EQ(0, size);
+}
+
+TEST_F(GoogleDriveFsTest, ReadContents) {
+  ScopedRef<GoogleDriveFsForTesting> fs(
+      new GoogleDriveFsForTesting(map_, &ppapi_));
+
+  Path file_path("/file");
+  ScopedNode file_node;
+  EXPECT_EQ(0, fs->Open(file_path, O_WRONLY | O_CREAT | O_APPEND, &file_node));
+
+  const char* contents = "contents";
+  int bytes_written;
+  EXPECT_EQ(0, file_node->Write(HandleAttr(), contents, strlen(contents),
+                                &bytes_written));
+  EXPECT_EQ(strlen(contents), bytes_written);
+
+  ScopedNode node;
+  ASSERT_EQ(0, fs->Open(file_path, O_RDONLY, &node));
+
+  //
+  // Read nothing past the end of the file.
+  //
+  char buffer[10] = {0};
+  int bytes_read;
+  HandleAttr attr;
+  attr.offs = 100;
+  ASSERT_EQ(0, node->Read(attr, &buffer[0], sizeof(buffer), &bytes_read));
+  ASSERT_EQ(0, bytes_read);
+
+  //
+  // Read from the beginning of the file. Buffer size > file size.
+  //
+  attr.offs = 0;
+  ASSERT_EQ(0, node->Read(attr, &buffer[0], sizeof(buffer), &bytes_read));
+  ASSERT_EQ(strlen(contents), bytes_read);
+  ASSERT_STREQ(contents, buffer);
+
+  //
+  // Read from the middle of the file. Buffer size > file size.
+  //
+  attr.offs = 4;
+  ASSERT_EQ(0, node->Read(attr, &buffer[0], sizeof(buffer), &bytes_read));
+  ASSERT_EQ(strlen(contents) - 4, bytes_read);
+  buffer[bytes_read] = 0;
+  ASSERT_STREQ("ents", buffer);
+
+  //
+  // Read from the beginning of the file. Buffer size < file size.
+  //
+  char buffer_smaller_than_file[5];
+  attr.offs = 0;
+  ASSERT_EQ(0, node->Read(attr, &buffer_smaller_than_file[0],
+                          sizeof(buffer_smaller_than_file), &bytes_read));
+  ASSERT_EQ(sizeof(buffer_smaller_than_file), bytes_read);
+  ASSERT_EQ('c', buffer_smaller_than_file[0]);
+  ASSERT_EQ('o', buffer_smaller_than_file[1]);
+  ASSERT_EQ('n', buffer_smaller_than_file[2]);
+  ASSERT_EQ('t', buffer_smaller_than_file[3]);
+  ASSERT_EQ('e', buffer_smaller_than_file[4]);
+
+  //
+  // Read from the middle of the file. Buffer size < file size.
+  //
+  attr.offs = 1;
+  ASSERT_EQ(0, node->Read(attr, &buffer_smaller_than_file[0],
+                          sizeof(buffer_smaller_than_file), &bytes_read));
+  ASSERT_EQ(sizeof(buffer_smaller_than_file), bytes_read);
+  ASSERT_EQ('o', buffer_smaller_than_file[0]);
+  ASSERT_EQ('n', buffer_smaller_than_file[1]);
+  ASSERT_EQ('t', buffer_smaller_than_file[2]);
+  ASSERT_EQ('e', buffer_smaller_than_file[3]);
+  ASSERT_EQ('n', buffer_smaller_than_file[4]);
+
+  //
+  // Read from the beginning of the file. Buffer size == file size.
+  //
+  char equal_buffer_size[8];
+  attr.offs = 0;
+  ASSERT_EQ(0, node->Read(attr, &equal_buffer_size[0],
+                          sizeof(equal_buffer_size), &bytes_read));
+  ASSERT_EQ(sizeof(equal_buffer_size), bytes_read);
+  ASSERT_EQ('c', equal_buffer_size[0]);
+  ASSERT_EQ('o', equal_buffer_size[1]);
+  ASSERT_EQ('n', equal_buffer_size[2]);
+  ASSERT_EQ('t', equal_buffer_size[3]);
+  ASSERT_EQ('e', equal_buffer_size[4]);
+  ASSERT_EQ('n', equal_buffer_size[5]);
+  ASSERT_EQ('t', equal_buffer_size[6]);
+  ASSERT_EQ('s', equal_buffer_size[7]);
+}
+
+TEST_F(GoogleDriveFsTest, ReadFailureCases) {
+  ScopedRef<GoogleDriveFsForTesting> fs(
+      new GoogleDriveFsForTesting(map_, &ppapi_));
+
+  Path file_path("/file");
+  ScopedNode file_node;
+  EXPECT_EQ(0, fs->Open(file_path, O_WRONLY | O_CREAT | O_APPEND, &file_node));
+
+  const char* contents = "contents";
+  int bytes_written;
+  EXPECT_EQ(0, file_node->Write(HandleAttr(), contents, strlen(contents),
+                                &bytes_written));
+  EXPECT_EQ(strlen(contents), bytes_written);
+
+  ScopedNode node;
+  ASSERT_EQ(0, fs->Open(file_path, O_WRONLY | O_CREAT | O_APPEND, &node));
+
+  //
+  // Reading from a file opened as write-only should fail.
+  //
+  char buffer[10];
+  int bytes_read = 1;  // Set to a non-zero value.
+  HandleAttr attr;
+  EXPECT_EQ(EACCES, node->Read(attr, &buffer[0], sizeof(buffer), &bytes_read));
+  EXPECT_EQ(0, bytes_read);
+
+  // mkdir on a directory that has not been existed.
+  Path dir_path("/dir");
+  ASSERT_EQ(0, fs->Mkdir(dir_path, 0644));
+
+  //
+  // Reading from a directory should fail.
+  //
+  ScopedNode dir_node;
+  ASSERT_EQ(0, fs->Open(dir_path, O_RDONLY, &dir_node));
+  ASSERT_EQ(EISDIR,
+            dir_node->Read(attr, &buffer[0], sizeof(buffer), &bytes_read));
+}
+
+TEST_F(GoogleDriveFsTest, WriteContents) {
+  ScopedRef<GoogleDriveFsForTesting> fs(
+      new GoogleDriveFsForTesting(map_, &ppapi_));
+
+  //
+  // Write from the beginning of the file.
+  //
+  Path file_path("/file");
+  ScopedNode file_node;
+  EXPECT_EQ(0, fs->Open(file_path, O_WRONLY | O_CREAT | O_APPEND, &file_node));
+
+  const char* contents = "contents";
+  int bytes_written;
+  EXPECT_EQ(0, file_node->Write(HandleAttr(), contents, strlen(contents),
+                                &bytes_written));
+  ASSERT_EQ(strlen(contents), bytes_written);
+
+  // Open as read-write.
+  ScopedNode node;
+  ASSERT_EQ(0, fs->Open(file_path, O_RDWR, &node));
+
+  //
+  // Write from the middle of the file.
+  //
+  bytes_written = 1;  // Set to a non-zero value.
+  HandleAttr attr;
+  attr.offs = 3;
+  EXPECT_EQ(0, node->Write(attr, "struct", 6, &bytes_written));
+  EXPECT_EQ(6, bytes_written);
+
+  char buffer[10];
+  attr.offs = 0;
+  int bytes_read;
+  EXPECT_EQ(0, node->Read(attr, &buffer[0], sizeof(buffer), &bytes_read));
+  EXPECT_EQ(9, bytes_read);
+  buffer[bytes_read] = 0;
+  EXPECT_STREQ("construct", buffer);
+}
+
+TEST_F(GoogleDriveFsTest, WriteFailureCases) {
+  ScopedRef<GoogleDriveFsForTesting> fs(
+      new GoogleDriveFsForTesting(map_, &ppapi_));
+
+  Path file_path("/file");
+  ScopedNode file_node;
+  EXPECT_EQ(0, fs->Open(file_path, O_WRONLY | O_CREAT | O_APPEND, &file_node));
+
+  const char* contents = "contents";
+  int bytes_written;
+  EXPECT_EQ(0, file_node->Write(HandleAttr(), contents, strlen(contents),
+                                &bytes_written));
+  EXPECT_EQ(strlen(contents), bytes_written);
+
+  ScopedNode node;
+  ASSERT_EQ(0, fs->Open(file_path, O_RDONLY, &node));
+
+  //
+  // Writing from a file opened as read-only should fail.
+  //
+  bytes_written = 1;  // Set to a non-zero value.
+  HandleAttr attr;
+  attr.offs = 0;
+  char buffer[10];
+  ASSERT_EQ(EACCES,
+            node->Write(attr, &buffer[0], sizeof(buffer), &bytes_written));
+  ASSERT_EQ(0, bytes_written);
+
+  // mkdir on a directory that has not been existed.
+  Path dir_path("/dir");
+  ASSERT_EQ(0, fs->Mkdir(dir_path, 0644));
+
+  //
+  // Writing to a directory should fail.
+  //
+  EXPECT_EQ(0, fs->Open(dir_path, O_RDONLY, &node));
+  int bytes_read;
+  EXPECT_EQ(EISDIR, node->Write(attr, &buffer[0], sizeof(buffer), &bytes_read));
+}
+
+TEST_F(GoogleDriveFsTest, GetStat) {
+  ScopedRef<GoogleDriveFsForTesting> fs(
+      new GoogleDriveFsForTesting(map_, &ppapi_));
+
+  //
+  // GetStat on a file.
+  //
+  ScopedNode node;
+  ASSERT_EQ(0, fs->Open(Path("/file"), O_WRONLY | O_CREAT | O_APPEND, &node));
+
+  const char* contents = "contents";
+  int bytes_written;
+  EXPECT_EQ(
+      0, node->Write(HandleAttr(), contents, strlen(contents), &bytes_written));
+  ASSERT_EQ(strlen(contents), bytes_written);
+
+  struct stat statbuf;
+  EXPECT_EQ(0, node->GetStat(&statbuf));
+  EXPECT_TRUE(S_ISREG(statbuf.st_mode));
+  EXPECT_EQ(S_IWRITE, statbuf.st_mode & S_MODEBITS);
+  EXPECT_EQ(strlen(contents), statbuf.st_size);
+  EXPECT_EQ(0, statbuf.st_atime);
+  EXPECT_EQ(0, statbuf.st_ctime);
+
+  // UTC time "2016-07-24T08:21:28.940Z" specified at each file
+  // in FakeGoogleDriveServer is equal to the UNIX timestamp 1469348488
+  EXPECT_EQ(1469348488, statbuf.st_mtime);
+
+  // Test Get* and Isa* methods.
+  off_t size;
+  EXPECT_EQ(0, node->GetSize(&size));
+  EXPECT_EQ(strlen(contents), size);
+  EXPECT_FALSE(node->IsaDir());
+  EXPECT_TRUE(node->IsaFile());
+  EXPECT_EQ(ENOTTY, node->Isatty());
+
+  Path path("/dir");
+  ASSERT_EQ(0, fs->Mkdir(path, 0644));
+
+  //
+  // GetStat on a directory.
+  //
+  EXPECT_EQ(0, fs->Open(path, O_RDONLY, &node));
+  EXPECT_EQ(0, node->GetStat(&statbuf));
+  EXPECT_TRUE(S_ISDIR(statbuf.st_mode));
+  EXPECT_EQ(S_IREAD, statbuf.st_mode & S_MODEBITS);
+  EXPECT_EQ(0, statbuf.st_size);
+  EXPECT_EQ(0, statbuf.st_atime);
+  EXPECT_EQ(0, statbuf.st_ctime);
+
+  // UTC time "2016-07-24T08:21:28.940Z" specified at each directory
+  // in FakeGoogleDriveServer is equal to the UNIX timestamp 1469348488;
+  EXPECT_EQ(1469348488, statbuf.st_mtime);
+
+  // Test Get* and Isa* methods.
+  EXPECT_EQ(0, node->GetSize(&size));
+  EXPECT_EQ(0, size);
+  EXPECT_TRUE(node->IsaDir());
+  EXPECT_FALSE(node->IsaFile());
+  EXPECT_EQ(ENOTTY, node->Isatty());
+}
+
+TEST_F(GoogleDriveFsTest, FTruncate) {
+  ScopedRef<GoogleDriveFsForTesting> fs(
+      new GoogleDriveFsForTesting(map_, &ppapi_));
+
+  ScopedNode node;
+  ASSERT_EQ(0, fs->Open(Path("/file"), O_RDWR | O_CREAT | O_TRUNC, &node));
+  const char* contents = "contents";
+  int bytes_written;
+  EXPECT_EQ(
+      0, node->Write(HandleAttr(), contents, strlen(contents), &bytes_written));
+  ASSERT_EQ(strlen(contents), bytes_written);
+
+  HandleAttr attr;
+  char buffer[10] = {0};
+  int bytes_read;
+
+  //
+  // First make the file shorter...
+  //
+  EXPECT_EQ(0, node->FTruncate(4));
+  EXPECT_EQ(0, node->Read(attr, &buffer[0], sizeof(buffer), &bytes_read));
+  EXPECT_EQ(4, bytes_read);
+  buffer[bytes_read] = 0;
+  EXPECT_STREQ("cont", buffer);
+
+  //
+  // Now make the file longer...
+  //
+  EXPECT_EQ(0, node->FTruncate(8));
+  EXPECT_EQ(0, node->Read(attr, &buffer[0], sizeof(buffer), &bytes_read));
+  EXPECT_EQ(8, bytes_read);
+  buffer[bytes_read] = 0;
+  EXPECT_STREQ("cont\0\0\0\0", buffer);
+
+  Path path("/dir");
+  ASSERT_EQ(0, fs->Mkdir(path, 0644));
+
+  //
+  // Ftruncate should fail for a directory.
+  //
+  EXPECT_EQ(0, fs->Open(path, O_RDONLY, &node));
+  EXPECT_EQ(EISDIR, node->FTruncate(4));
+}
+
+TEST_F(GoogleDriveFsTest, OpenDirectory) {
+  ScopedRef<GoogleDriveFsForTesting> fs(
+      new GoogleDriveFsForTesting(map_, &ppapi_));
+
+  Path dir_path("/dir");
+  ASSERT_EQ(0, fs->Mkdir(dir_path, 0644));
+
+  //
+  // Open a directory with r mode should succeed.
+  //
+  ScopedNode node;
+  ASSERT_EQ(0, fs->Open(dir_path, O_RDONLY, &node));
+
+  //
+  // Open a directory with r+, w, w+, a, and a+ mode should fail.
+  //
+  EXPECT_EQ(EPERM, fs->Open(dir_path, O_RDWR, &node));
+  EXPECT_EQ(EPERM, fs->Open(dir_path, O_WRONLY | O_CREAT | O_TRUNC, &node));
+  EXPECT_EQ(EPERM, fs->Open(dir_path, O_RDWR | O_CREAT | O_TRUNC, &node));
+  EXPECT_EQ(EPERM, fs->Open(dir_path, O_WRONLY | O_CREAT | O_APPEND, &node));
+  EXPECT_EQ(EPERM, fs->Open(dir_path, O_RDWR | O_CREAT | O_APPEND, &node));
+
+  //
+  // Opening a non-existing directory should fail.
+  //
+  EXPECT_EQ(ENOENT, fs->Open(Path("/nonexistingdir"), O_RDONLY, &node));
+}
+
+TEST_F(GoogleDriveFsTest, GetDents) {
+  ScopedRef<GoogleDriveFsForTesting> fs(
+      new GoogleDriveFsForTesting(map_, &ppapi_));
+
+  ScopedNode node;
+  Path file_path("/file");
+  ASSERT_EQ(0, fs->Open(file_path, O_WRONLY | O_CREAT | O_TRUNC, &node));
+  const char* contents = "contents";
+  int bytes_written;
+  EXPECT_EQ(
+      0, node->Write(HandleAttr(), contents, strlen(contents), &bytes_written));
+  ASSERT_EQ(strlen(contents), bytes_written);
+
+  ScopedNode root;
+  ASSERT_EQ(0, fs->Open(Path("/"), O_RDONLY, &root));
+
+  struct stat stat;
+  ASSERT_EQ(0, node->GetStat(&stat));
+
+  //
+  // Should fail for regular files.
+  //
+  const size_t kMaxDirents = 5;
+  dirent dirents[kMaxDirents];
+  int bytes_read = 1;  // Set to a non-zero value.
+
+  memset(&dirents[0], 0, sizeof(dirents));
+  EXPECT_EQ(ENOTDIR,
+            node->GetDents(0, &dirents[0], sizeof(dirents), &bytes_read));
+  EXPECT_EQ(0, bytes_read);
+
+  //
+  // Should work with root directory.
+  //
+  // +2 to test a size that is not a multiple of sizeof(dirent).
+  // Expect it to round down.
+  memset(&dirents[0], 0, sizeof(dirents));
+  EXPECT_EQ(
+      0, root->GetDents(0, &dirents[0], sizeof(dirent) * 3 + 2, &bytes_read));
+
+  {
+    size_t num_dirents = bytes_read / sizeof(dirent);
+    EXPECT_EQ(3, num_dirents);
+    EXPECT_EQ(sizeof(dirent) * num_dirents, bytes_read);
+
+    std::multiset<std::string> dirnames;
+    for (size_t i = 0; i < num_dirents; ++i) {
+      EXPECT_EQ(sizeof(dirent), dirents[i].d_reclen);
+      dirnames.insert(dirents[i].d_name);
+    }
+
+    EXPECT_EQ(1, dirnames.count("file"));
+    EXPECT_EQ(1, dirnames.count("."));
+    EXPECT_EQ(1, dirnames.count(".."));
+  }
+
+  // Add another file...
+  ASSERT_EQ(0, fs->Open(Path("/file2"), O_WRONLY | O_CREAT | O_TRUNC, &node));
+  ASSERT_EQ(0, node->GetStat(&stat));
+
+  //
+  // Read the root directory again after adding another file.
+  //
+  memset(&dirents[0], 0, sizeof(dirents));
+  EXPECT_EQ(0, root->GetDents(0, &dirents[0], sizeof(dirents), &bytes_read));
+
+  {
+    size_t num_dirents = bytes_read / sizeof(dirent);
+    EXPECT_EQ(4, num_dirents);
+    EXPECT_EQ(sizeof(dirent) * num_dirents, bytes_read);
+
+    std::multiset<std::string> dirnames;
+    for (size_t i = 0; i < num_dirents; ++i) {
+      EXPECT_EQ(sizeof(dirent), dirents[i].d_reclen);
+      dirnames.insert(dirents[i].d_name);
+    }
+
+    EXPECT_EQ(1, dirnames.count("file"));
+    EXPECT_EQ(1, dirnames.count("file2"));
+    EXPECT_EQ(1, dirnames.count("."));
+    EXPECT_EQ(1, dirnames.count(".."));
+  }
+
+  //
+  // Read >100 entries. Multiple API requests are sent to request >100 entries.
+  //
+  const size_t kMaxDirectsMultipleRequests = 105;
+  std::vector<dirent> direntsMultipleRequests;
+  direntsMultipleRequests.resize(kMaxDirectsMultipleRequests);
+
+  // Add 100 files...
+  for (size_t i = 0; i < 100; ++i) {
+    char buffer[4];
+    snprintf(buffer, sizeof(buffer), "%u", i);
+
+    ASSERT_EQ(0, fs->Open(Path("/anotherfile" + std::string(buffer)),
+                          O_WRONLY | O_CREAT | O_TRUNC, &node));
+    ASSERT_EQ(0, node->GetStat(&stat));
+  }
+
+  EXPECT_EQ(0, root->GetDents(0, &direntsMultipleRequests[0],
+                              sizeof(dirent) * direntsMultipleRequests.size(),
+                              &bytes_read));
+  {
+    size_t num_dirents = bytes_read / sizeof(dirent);
+    EXPECT_EQ(104, num_dirents);
+    EXPECT_EQ(sizeof(dirent) * num_dirents, bytes_read);
+
+    std::multiset<std::string> dirnames;
+    for (size_t i = 0; i < num_dirents; ++i) {
+      EXPECT_EQ(sizeof(dirent), direntsMultipleRequests[i].d_reclen);
+      dirnames.insert(direntsMultipleRequests[i].d_name);
+    }
+
+    for (size_t i = 0; i < 100; ++i) {
+      char buffer[4];
+      snprintf(buffer, sizeof(buffer), "%u", i);
+
+      EXPECT_EQ(1, dirnames.count("anotherfile" + std::string(buffer)));
+    }
+
+    EXPECT_EQ(1, dirnames.count("file"));
+    EXPECT_EQ(1, dirnames.count("file2"));
+    EXPECT_EQ(1, dirnames.count("."));
+    EXPECT_EQ(1, dirnames.count(".."));
+  }
+}
+
+// TODO: Add tests after Remove becomes supported.
+// TODO: Add tests after Unlink becomes supported.
+// TODO: Add tests after Rename becomes supported.