message: Add test NewAppendableFile
diff: @@ -209,6 +209,21 @@ TEST_F(S3FilesystemTest, NewWritableFile) {
  EXPECT_EQ("content1,content2", content);
  }
  +TEST_F(S3FilesystemTest, NewAppendableFile) {
  + const std::string path = GetURIForPath("AppendableFile");
  + WriteString(path, "test");
  + ASSERT_TF_OK(status_);
  +
  + auto writer = GetWriter();
  + tf_s3_filesystem::NewAppendableFile(filesystem_, path.c_str(), writer.get(),
  + status_);
  + EXPECT_TF_OK(status_);
  + tf_writable_file::Append(writer.get(), "content", strlen("content"), status_);
  + EXPECT_TF_OK(status_);
  + tf_writable_file::Close(writer.get(), status_);
  + EXPECT_TF_OK(status_);
  +}
  +
  } // namespace
  } // namespace tensorflow
  