diff --git a/tests/unit/dirutil_test.cpp b/tests/unit/dirutil_test.cpp
new file mode 100644
index 0000000..5e2ae4f
--- /dev/null
+++ b/tests/unit/dirutil_test.cpp
@@ -0,0 +1,150 @@
+/*
+ * Copyright 2016 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <errno.h>
+#include <sys/stat.h>
+#include <unistd.h>
+
+#include <string>
+
+#include <android-base/test_utils.h>
+#include <gtest/gtest.h>
+#include <otautil/DirUtil.h>
+
+TEST(DirUtilTest, create_invalid) {
+  // Requesting to create an empty dir is invalid.
+  ASSERT_EQ(-1, dirCreateHierarchy("", 0755, nullptr, false, nullptr));
+  ASSERT_EQ(ENOENT, errno);
+
+  // Requesting to strip the name with no slash present.
+  ASSERT_EQ(-1, dirCreateHierarchy("abc", 0755, nullptr, true, nullptr));
+  ASSERT_EQ(ENOENT, errno);
+
+  // Creating a dir that already exists.
+  TemporaryDir td;
+  ASSERT_EQ(0, dirCreateHierarchy(td.path, 0755, nullptr, false, nullptr));
+
+  // "///" is a valid dir.
+  ASSERT_EQ(0, dirCreateHierarchy("///", 0755, nullptr, false, nullptr));
+
+  // Request to create a dir, but a file with the same name already exists.
+  TemporaryFile tf;
+  ASSERT_EQ(-1, dirCreateHierarchy(tf.path, 0755, nullptr, false, nullptr));
+  ASSERT_EQ(ENOTDIR, errno);
+}
+
+TEST(DirUtilTest, create_smoke) {
+  TemporaryDir td;
+  std::string prefix(td.path);
+  std::string path = prefix + "/a/b";
+  constexpr mode_t mode = 0755;
+  ASSERT_EQ(0, dirCreateHierarchy(path.c_str(), mode, nullptr, false, nullptr));
+
+  // Verify.
+  struct stat sb;
+  ASSERT_EQ(0, stat(path.c_str(), &sb)) << strerror(errno);
+  ASSERT_TRUE(S_ISDIR(sb.st_mode));
+  constexpr mode_t mask = S_IRWXU | S_IRWXG | S_IRWXO;
+  ASSERT_EQ(mode, sb.st_mode & mask);
+
+  // Clean up.
+  ASSERT_EQ(0, rmdir((prefix + "/a/b").c_str()));
+  ASSERT_EQ(0, rmdir((prefix + "/a").c_str()));
+}
+
+TEST(DirUtilTest, create_strip_filename) {
+  TemporaryDir td;
+  std::string prefix(td.path);
+  std::string path = prefix + "/a/b";
+  ASSERT_EQ(0, dirCreateHierarchy(path.c_str(), 0755, nullptr, true, nullptr));
+
+  // Verify that "../a" exists but not "../a/b".
+  struct stat sb;
+  ASSERT_EQ(0, stat((prefix + "/a").c_str(), &sb)) << strerror(errno);
+  ASSERT_TRUE(S_ISDIR(sb.st_mode));
+
+  ASSERT_EQ(-1, stat(path.c_str(), &sb));
+  ASSERT_EQ(ENOENT, errno);
+
+  // Clean up.
+  ASSERT_EQ(0, rmdir((prefix + "/a").c_str()));
+}
+
+TEST(DirUtilTest, create_mode_and_timestamp) {
+  TemporaryDir td;
+  std::string prefix(td.path);
+  std::string path = prefix + "/a/b";
+  // Set the timestamp to 8/1/2008.
+  constexpr struct utimbuf timestamp = { 1217592000, 1217592000 };
+  constexpr mode_t mode = 0751;
+  ASSERT_EQ(0, dirCreateHierarchy(path.c_str(), mode, &timestamp, false, nullptr));
+
+  // Verify the mode and timestamp for "../a/b".
+  struct stat sb;
+  ASSERT_EQ(0, stat(path.c_str(), &sb)) << strerror(errno);
+  ASSERT_TRUE(S_ISDIR(sb.st_mode));
+  constexpr mode_t mask = S_IRWXU | S_IRWXG | S_IRWXO;
+  ASSERT_EQ(mode, sb.st_mode & mask);
+
+  timespec time;
+  time.tv_sec = 1217592000;
+  time.tv_nsec = 0;
+
+  ASSERT_EQ(time.tv_sec, static_cast<long>(sb.st_atime));
+  ASSERT_EQ(time.tv_sec, static_cast<long>(sb.st_mtime));
+
+  // Verify the mode for "../a". Note that the timestamp for intermediate directories (e.g. "../a")
+  // may not be 'timestamp' according to the current implementation.
+  ASSERT_EQ(0, stat((prefix + "/a").c_str(), &sb)) << strerror(errno);
+  ASSERT_TRUE(S_ISDIR(sb.st_mode));
+  ASSERT_EQ(mode, sb.st_mode & mask);
+
+  // Clean up.
+  ASSERT_EQ(0, rmdir((prefix + "/a/b").c_str()));
+  ASSERT_EQ(0, rmdir((prefix + "/a").c_str()));
+}
+
+TEST(DirUtilTest, unlink_invalid) {
+  // File doesn't exist.
+  ASSERT_EQ(-1, dirUnlinkHierarchy("doesntexist"));
+
+  // Nonexistent directory.
+  TemporaryDir td;
+  std::string path(td.path);
+  ASSERT_EQ(-1, dirUnlinkHierarchy((path + "/a").c_str()));
+  ASSERT_EQ(ENOENT, errno);
+}
+
+TEST(DirUtilTest, unlink_smoke) {
+  // Unlink a file.
+  TemporaryFile tf;
+  ASSERT_EQ(0, dirUnlinkHierarchy(tf.path));
+  ASSERT_EQ(-1, access(tf.path, F_OK));
+
+  TemporaryDir td;
+  std::string path(td.path);
+  constexpr mode_t mode = 0700;
+  ASSERT_EQ(0, mkdir((path + "/a").c_str(), mode));
+  ASSERT_EQ(0, mkdir((path + "/a/b").c_str(), mode));
+  ASSERT_EQ(0, mkdir((path + "/a/b/c").c_str(), mode));
+  ASSERT_EQ(0, mkdir((path + "/a/d").c_str(), mode));
+
+  // Remove "../a" recursively.
+  ASSERT_EQ(0, dirUnlinkHierarchy((path + "/a").c_str()));
+
+  // Verify it's gone.
+  ASSERT_EQ(-1, access((path + "/a").c_str(), F_OK));
+}