node/test/simple/test-child-process-exec-env.js

var common = require('../common');
var assert = require('assert');
var exec = require('child_process').exec;
var success_count = 0;
var error_count = 0;
var response = '';

var child = exec('/usr/bin/env', {env: {'HELLO': 'WORLD'}},
                 function(err, stdout, stderr) {
                   if (err) {
                     error_count++;
                     console.log('error!: ' + err.code);
                     console.log('stdout: ' + JSON.stringify(stdout));
                     console.log('stderr: ' + JSON.stringify(stderr));
                     assert.equal(false, err.killed);
                   } else {
                     success_count++;
                     assert.equal(true, stdout != '');
                   }
                 });

child.stdout.setEncoding('utf8');

child.stdout.addListener('data', function(chunk) {
  response += chunk;
});

process.addListener('exit', function() {
  assert.equal(1, success_count);
  assert.equal(0, error_count);
  assert.ok(response.indexOf('HELLO=WORLD') >= 0);
});