node/test/simple/test-pipe-head.js

var common = require('../common');
var assert = require('assert');

var exec = require('child_process').exec;
var join = require('path').join;

var nodePath = process.argv[0];
var script = join(common.fixturesDir, 'print-10-lines.js');

var cmd = nodePath + ' ' + script + ' | head -2';

var finished = false;

exec(cmd, function(err, stdout, stderr) {
  if (err) throw err;
  var lines = stdout.split('\n');
  assert.equal(3, lines.length);
  finished = true;
});


process.addListener('exit', function() {
  assert.ok(finished);
});