Ruby minitest/unit-test template for using Tempfile

ruby_minitest_unittest_tempfile.rb

gem "minitest"
require 'minitest/autorun'
require 'tempfile'

# In general, each test method should generate its own temporary files.
# With the following code, the temporary files will be automatically deleted 
# at the end of the processing, even if their IOs have been alraedy closed
# and only the filename (path) were utilised during processing.

class TestUnitMyLibrary < MiniTest::Test
  def setup
    # Array of IOs for temporary files (automatically set in generate_tmpfile())
    @tmpfiles = []
  end

  def teardown
    @tmpfiles.each do |ef|
      ef.close if !ef.closed? 
      File.unlink(ef.path)
    end
  end

  # @option root [#to_s] Root-name of the temporary filename
  def generate_tmpfile(root=File.basename($0))
    io_tmpfile = Tempfile.open(root.to_s)
    $stderr.print "TEST: Tmpfile="+io_tmpfile.path if ENV.key?('PRINT_TMPFILE') # To display Filename (NOTE the file will be removed when the script ends anyway.)
    @tmpfiles.push io_tmpfile
    [io_tmpfile, io_tmpfile.path]
  end

  def test_method1
    io_tmp, path_tmp = generate_tmpfile(__method__)
    io_tmp.puts "my message"  # Write to a temporary file
    io_tmp.rewind
    msg_log = io_tmp.read     # Read the contents of the temporary file

    # You can use only the filename (path), if desired.
    io_tmp.close
    system "echo abc > #{path_tmp}"
    # the file is automatically deleted at the end.
  end
end

#
# If a single method uses a temporary file, the following is suffice.
#
require 'tempfile'

class TestUnitMyLibrary < MiniTest::Test
  def setup
    @io_tmpfile = Tempfile.open('test_pandoc')
    @tmpfilename = @io_tmpfile.path
    $stderr.print "TEST: Tmpfile="+@tmpfilename if ENV.key?('PRINT_TMPFILE') # To display Filename (NOTE the file will be removed when the script ends anyway.)
  end

  def teardown
    if !@io_tmpfile.closed? 
      @io_tmpfile.close
    end
    File.unlink(@tmpfilename) if File.exist?(@tmpfilename)
  end

  def test_method1
    @io_tmpfile.puts "my message"
    @io_tmpfile.rewind
    msg_log = @io_tmpfile.read
  end
end