gulpfile.js

var gulp = require('gulp');

function exec(command, env) {
  require('child_process').execSync(command, {
    stdio: 'inherit',
    env: Object.assign({}, process.env, env, {
      PATH: `./node_modules/.bin:${process.env.PATH}`
    })
  });
}

var environments = ['development', 'test', 'integration1', 'uat', 'prod'];

environments.forEach(env => {
  gulp.task(`build:${env}`, () => {
    exec(`echo Building ${env}`);
    exec(`rimraf dist/${env}`);
    exec(`webpack --color`, {
      NODE_ENV: 'build',
      MMR_ENV: env
    });
  });
});