I have made an adaptation of Pas2js for Delphi compiler. So now it's possible to compile and debug the code of this utility in Delphi IDE.
If somebody interested you can find it here: https://github.com/Kryuski/pas2js-for-delphi.
The original Pas2js transpiler for Free Pascal is here: http://wiki.freepascal.org/pas2js