Module: TraceFiles

Defined in:
lib/trace_files.rb,
lib/trace_files/version.rb

Constant Summary collapse

VERSION = 
'1.0.0'
DATE = 
'2015-06-18'

Class Method Summary collapse

Class Method Details

.set(spec_opts) ⇒ TracePoint

Trace file source to :io (default $stdout)

spec_opts = {}

Parameters:

  • :trace (Array<String>) —

    the files to trace

  • :io (IO) —

    io to print to

Returns:

  • (TracePoint) —

    the trace point object



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# File 'lib/trace_files.rb', line 12

def self.set spec_opts
  targets   = []
  files     = {}
  last_file = ''
  last_line = -1

  files_to_trace = spec_opts.fetch(:trace, []);
  io    = spec_opts.fetch(:io, $stdout)
  color = spec_opts.fetch(:color, "\e[32m") # ANSI.green default
  # target only existing readable files
  files_to_trace.each do |f|
    if File.exists?(f) && File.readable?(f)
      targets.push File.expand_path f
      targets.push File.basename f # sometimes the file is relative
    end
  end
  return if targets.empty?

  trace_point = TracePoint.new do |trace|
    file_path = trace.path
    if targets.include?(file_path)
      line_number = trace.lineno
      # never repeat a line
      unless file_path == last_file && line_number == last_line
        file_sym        = file_path.intern
        files[file_sym] = IO.readlines(file_path) if files[file_sym].nil?
        lines           = files[file_sym]

        # arrays are 0 indexed and line numbers start at one.
        io.print color if color # ANSI code
        io.puts lines[line_number - 1]
        io.print "\e[0m" if color # ANSI.clear

        last_file = file_path
        last_line = line_number
      end
    end
  end

  trace_point.enable
  trace_point
end