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

'use strict';
const common = require('../common');
const assert = require('assert');

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

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

const cmd = `"${nodePath}" "${script}" | head -2`;

exec(cmd, common.mustCall(function(err, stdout, stderr) {
  assert.ifError(err);
  const lines = stdout.split('\n');
  assert.strictEqual(3, lines.length);
}));