Tempfile is a utility class for managing temporary files. When you create a
Tempfile object, it will create a temporary file with a unique filename. A
Tempfile objects behaves just like a File object, and you can perform all the
usual file operations on it: reading data, writing data, changing its
permissions, etc. So although this class does not explicitly document all
instance methods supported by File, you can in fact call any File instance
method on a Tempfile object.

WWW: https://github.com/ruby/tempfile