1 files changed, 69 insertions, 0 deletions
diff --git a/third_party/libwebrtc/rtc_base/system/file_wrapper_unittest.cc b/third_party/libwebrtc/rtc_base/system/file_wrapper_unittest.cc
new file mode 100644
index 0000000000..980b565c73
--- /dev/null
+++ b/third_party/libwebrtc/rtc_base/system/file_wrapper_unittest.cc
@@ -0,0 +1,69 @@
+/*
+ *  Copyright 2021 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "rtc_base/system/file_wrapper.h"
+
+#include "rtc_base/checks.h"
+#include "test/gtest.h"
+#include "test/testsupport/file_utils.h"
+
+namespace webrtc {
+
+TEST(FileWrapper, FileSize) {
+  auto test_info = ::testing::UnitTest::GetInstance()->current_test_info();
+  std::string test_name =
+      std::string(test_info->test_case_name()) + "_" + test_info->name();
+  std::replace(test_name.begin(), test_name.end(), '/', '_');
+  const std::string temp_filename = test::OutputPath() + test_name;
+
+  // Write
+  {
+    FileWrapper file = FileWrapper::OpenWriteOnly(temp_filename);
+    ASSERT_TRUE(file.is_open());
+    EXPECT_EQ(file.FileSize(), 0);
+
+    EXPECT_TRUE(file.Write("foo", 3));
+    EXPECT_EQ(file.FileSize(), 3);
+
+    // FileSize() doesn't change the file size.
+    EXPECT_EQ(file.FileSize(), 3);
+
+    // FileSize() doesn't move the write position.
+    EXPECT_TRUE(file.Write("bar", 3));
+    EXPECT_EQ(file.FileSize(), 6);
+  }
+
+  // Read
+  {
+    FileWrapper file = FileWrapper::OpenReadOnly(temp_filename);
+    ASSERT_TRUE(file.is_open());
+    EXPECT_EQ(file.FileSize(), 6);
+
+    char buf[10];
+    size_t bytes_read = file.Read(buf, 3);
+    EXPECT_EQ(bytes_read, 3u);
+    EXPECT_EQ(memcmp(buf, "foo", 3), 0);
+
+    // FileSize() doesn't move the read position.
+    EXPECT_EQ(file.FileSize(), 6);
+
+    // Attempting to read past the end reads what is available
+    // and sets the EOF flag.
+    bytes_read = file.Read(buf, 5);
+    EXPECT_EQ(bytes_read, 3u);
+    EXPECT_EQ(memcmp(buf, "bar", 3), 0);
+    EXPECT_TRUE(file.ReadEof());
+  }
+
+  // Clean up temporary file.
+  remove(temp_filename.c_str());
+}
+
+}  // namespace webrtc