module SimpleCov::CLI::Open

def browser_opener

before the path so a quoted path isn't mis-parsed as the title.
the empty string is the window-title positional `start` takes
cmd.exe builtin (not an executable), so route through `cmd /c`;
nil if the host OS isn't recognized. On Windows, `start` is a
Returns the argv for the platform's "open this file" command, or 
def browser_opener
  case RbConfig::CONFIG["host_os"]
  when /darwin/             then ["open"]
  when /mswin|mingw|cygwin/ then ["cmd", "/c", "start", ""]
  when /linux|bsd|solaris/  then ["xdg-open"]
  end
end

def error(stderr, message) 

def error(stderr, message)
  stderr.puts("simplecov open: #{message}")
  1
end

def parse(args) 

def parse(args)
  path = SimpleCov::CLI.default_report
  OptionParser.new do |o|
    o.on("--report PATH") { |v| path = v }
  end.parse(args)
  path
end

def run(args, stderr:, **) 

def run(args, stderr:, **)
  path = parse(args)
  return error(stderr, "#{path} not found") unless File.exist?(path)
  opener = browser_opener
  return error(stderr, "no known opener for #{RbConfig::CONFIG['host_os']}") unless opener
  system(*opener, path) ? 0 : 1
end