Some test helpers to make sure something is or isn't logged

log_test_helpers.rb

module LogTestHelpers
  def exclude_from_logs(*hits, &block)
    exclude_from_other_logs(test_log_path, *hits, &block)
  end
  alias :expect_logs_to_not_include :exclude_from_logs

  def exclude_from_other_logs(log_path=test_log_path, *hits, &block)
    lines_to_scan = scan_logs log_path, &block

    regex = Regexp.union *hits
    expect(lines_to_scan.join("\n")).to_not match regex
  end

  def include_in_logs(*hits, &block)
    include_in_other_logs(test_log_path, *hits, &block)
  end
  alias :expect_logs_to_include :include_in_logs

  def include_in_other_logs(log_path=test_log_path, *hits, &block)
    lines_to_scan = scan_logs log_path, &block

    regex = Regexp.union *hits
    expect(lines_to_scan.join("\n")).to match regex
  end

  def scan_logs(log_path =test_log_path)
    log_starting_point = File.size(log_path)

    yield  # This is where we run the actual code that is writing to the log

    File.read(log_path, nil, log_starting_point, {mode: 'r'}).lines
  end
  
  def test_log_path
    "log/test.log"
  end
end