code: function findOnLine(find, patch, cb) {
      if (find.test(patch)) {
          var lineNum = 0
          patch.split('\n').forEach(function(line) {
              var range = /\@\@ \-\d+,\d+ \+(\d+),\d+ \@\@/g.exec(line)
              if (range) {
                  lineNum = Number(range[1]) - 1
              } else if (line.substr(0, 1) !== '-') {
                  lineNum++
              }
              if (find.test(line)) {
                  return cb(null, lineNum)
              }
          })
      }
  }
docs: find stuff in a diff and return the line number