mocha-proc.js

// run with "mocha mocha-proc.js"

var spawn  = require('child_process').spawn
  , should = require('should')

describe('your thing', function () {
  it('should do some stuff', function (done) {
    
    var ls = spawn('ls', ['-lh', '/usr']);

    ls.stdout.on('data', function (data) {
      // Check for data, call done()
      console.log('stdout: ' + data);
    });
    
    ls.stderr.on('data', function (data) {
      // OR check for data and call done() or throw some errors
      console.log('stderr: ' + data);
    });
    
    ls.on('close', function (code) {
      // OR check for status code and call done()
      console.log('child process exited with code ' + code);
      code.should.equal(0);
      done();
    });
  });
});