Contents

module Test
end unless defined?(Test)

##
# test-cmd.rb is a library for accessing the output streams
# (both stdout and stderr) of a spawned process. The library was
# first realized in a test environment, where it provided a path
# for verifying that when code examples are run they produce the
# expected output. The library can be generally useful outside a
# test environment, too.
module Test::Cmd
  class Result
    require "tempfile"
    ##
    # @return [String]
    #  Returns the contents of stdout
    attr_reader :stdout

    ##
    # @return [String]
    #  Returns the contents of stderr
    attr_reader :stderr

    ## @return [Process::Status]
    #  Returns the status of a process
    attr_reader :status

    ##
    # @param [Tempfile] stdout
    # @param [Tempfile] stderr
    # @param [Process::Status] pstatus
    # @return [Test::Cmd::Result]
    def initialize(stdout, stderr, pstatus)
      @stdout = stdout.tap(&:rewind).read
      @stderr = stderr.tap(&:rewind).read
      @status = pstatus
    end

    ##
    # @return [Integer]
    #  Returns the exit status of a process
    def exit_status
      @status.exitstatus
    end

    ##
    # Yields each line of stdout when the command
    # was successful, or each line of stderr when
    # the command was not successful.
    #
    # @return [Enumerator]
    #  Returns an Enumerator when a block is not given.
    def each_line
      return enum_for(:each_line) unless block_given?
      io = @status.success? ? @stdout : @stderr
      io.each_line.each { yield(_1.chomp) }
    end
  end

  ##
  # @param [String] cmd
  #  A command to execute
  #
  # @return [Test::Cmd::Result]
  #  Returns an instance of {Test::Cmd::Result Test::Cmd::Result}
  def cmd(cmd)
    out = Tempfile.new("cmd-stdout").tap(&:unlink)
    err = Tempfile.new("cmd-stderr").tap(&:unlink)
    Process.wait spawn(cmd, {err:, out:})
    Result.new(out, err, $?)
  ensure
    out.close
    err.close
  end
  module_function :cmd
end

Version data entries

2 entries across 2 versions & 1 rubygems

Version	Path
test-cmd.rb-0.4.2	lib/test-cmd.rb
test-cmd.rb-0.4.1	lib/test-cmd.rb