add console log to each function invocation

tracy.coffee

falafel = require 'falafel'
fs      = require 'fs'

raw    = process.argv[2]
cooked = raw.replace(/\.js$/, '-trace.js')

counter = 0

src     = fs.readFileSync(raw, encoding: 'utf8')
tracied = falafel src, (node) ->
  if node.type is 'FunctionExpression' or node.type is 'FunctionDeclaration'
    inner = node.body.source().slice(1,-1)
    name  = node.id?.name? || "anonymous_#{ ++counter }"

    node.body.update """
    {
      console.log("enter '#{ name }'");
      #{ inner }
    }
    """

fs.writeFileSync cooked, tracied