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

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

var spawn = require('child_process').spawn;
var child = spawn('/usr/bin/env', [], {env: {'HELLO' : 'WORLD'}});

var response = "";

child.stdout.setEncoding('utf8');

child.stdout.addListener("data", function (chunk) {
  console.log("stdout: " + chunk);
  response += chunk;
});

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