stream_helper.rb

# frozen_string_literal: true

# This borrows heavily from ActiveSupport::Testing::Stream to silence or capture STDOUT, STDERR.
# The main difference is #capture is renamed to #capture_stream, to avoid collision with Rails' #capture method.
module StreamHelper
  def silence_stream(stream)
    old_stream = stream.dup
    stream.reopen(IO::NULL)
    stream.sync = true
    yield
  ensure
    stream.reopen(old_stream)
    old_stream.close
  end

  def quietly(&block)
    silence_stream(STDOUT) do
      silence_stream(STDERR, &block)
    end
  end

  # #capture_stream is renamed from ActiveSupport::Testing::Stream#capture to avoid collision with Rails' #capture
  # method.
  def capture_stream(stream)
    stream = stream.to_s
    captured_stream = Tempfile.new(stream)
    stream_io = eval("$#{stream}")
    origin_stream = stream_io.dup
    stream_io.reopen(captured_stream)

    yield

    stream_io.rewind
    captured_stream.read
  ensure
    captured_stream.close
    captured_stream.unlink
    stream_io.reopen(origin_stream)
  end
end

RSpec.configure do |config|
  config.include StreamHelper
end