node/test/parallel/test-preload.js

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

var nodeBinary = process.argv[0];

var preloadOption = function(preloads) {
  var option = '';
  preloads.forEach(function(preload, index) {
    option += '-r ' + preload + ' ';
  });
  return option;
};

var fixture = function(name) {
  return path.join(common.fixturesDir, name);
};

var fixtureA = fixture('printA.js');
var fixtureB = fixture('printB.js');
var fixtureC = fixture('printC.js');
var fixtureThrows = fixture('throws_error4.js');

// test preloading a single module works
child_process.exec(nodeBinary + ' ' +
  preloadOption([fixtureA]) + ' ' +
  fixtureB,
  function(err, stdout, stderr) {
    if (err) throw err;
    assert.strictEqual(stdout, 'A\nB\n');
  });

// test preloading multiple modules works
child_process.exec(nodeBinary + ' ' +
  preloadOption([fixtureA, fixtureB]) + ' ' +
  fixtureC,
  function(err, stdout, stderr) {
    if (err) throw err;
    assert.strictEqual(stdout, 'A\nB\nC\n');
  });

// test that preloading a throwing module aborts
child_process.exec(nodeBinary + ' ' +
  preloadOption([fixtureA, fixtureThrows]) + ' ' +
  fixtureB,
  function(err, stdout, stderr) {
    if (err) {
      assert.strictEqual(stdout, 'A\n');
    } else {
      throw new Error('Preload should have failed');
    }
  });

// test that preload can be used with --eval
child_process.exec(nodeBinary + ' ' +
  preloadOption([fixtureA]) +
  '-e "console.log(\'hello\');"',
  function(err, stdout, stderr) {
    if (err) throw err;
    assert.strictEqual(stdout, 'A\nhello\n');
  });

// test that preload placement at other points in the cmdline
// also test that duplicated preload only gets loaded once
child_process.exec(nodeBinary + ' ' +
  preloadOption([fixtureA]) +
  '-e "console.log(\'hello\');" ' +
  preloadOption([fixtureA, fixtureB]),
  function(err, stdout, stderr) {
    if (err) throw err;
    assert.strictEqual(stdout, 'A\nB\nhello\n');
  });

child_process.exec(nodeBinary + ' ' +
  '--require ' + fixture('cluster-preload.js') + ' ' +
  fixture('cluster-preload-test.js'),
  function(err, stdout, stderr) {
    if (err) throw err;
    assert.ok(/worker terminated with code 43/.test(stdout));
  });

// https://github.com/nodejs/node/issues/1691
process.chdir(common.fixturesDir);
child_process.exec(nodeBinary + ' ' +
  '--expose_debug_as=v8debug ' +
  '--require ' + fixture('cluster-preload.js') + ' ' +
  'cluster-preload-test.js',
  function(err, stdout, stderr) {
    if (err) throw err;
    assert.ok(/worker terminated with code 43/.test(stdout));
  });