How to use the aurelia-cli.CLIOptions.getEnvironment function in aurelia-cli

function configureEnvironment() {
  let env = CLIOptions.getEnvironment();

  return gulp.src(`aurelia_project/environments/${env}${project.transpiler.fileExtension}`)
    .pipe(rename(`environment${project.transpiler.fileExtension}`))
    .pipe(gulp.dest(project.paths.root))
    .pipe(through.obj(function (file, enc,  cb) {
      // https://github.com/webpack/watchpack/issues/25#issuecomment-287789288
      var now = Date.now() / 1000;
      var then = now - 10;
      fs.utimes(file.path, then, then, function (err) { if (err) throw err });
      cb(null, file);
    }));
}

import gulp from 'gulp';
import plumber from 'gulp-plumber';
import babel from 'gulp-babel';
import notify from 'gulp-notify';
import rename from 'gulp-rename';
import cache from 'gulp-cache';
import project from '../aurelia.json';
import {CLIOptions, build, Configuration} from 'aurelia-cli';

let env = CLIOptions.getEnvironment();
const buildOptions = new Configuration(project.build.options);
const useCache = buildOptions.isApplicable('cache');

function configureEnvironment() {
  return gulp.src(`aurelia_project/environments/${env}.js`, {since: gulp.lastRun(configureEnvironment)})
    .pipe(rename('environment.js'))
    .pipe(gulp.dest(project.paths.root));
}

function buildJavaScript() {
  let transpile = babel(project.transpiler.options);
  if (useCache) {
    // the cache directory is "gulp-cache/projName-env" inside folder require('os').tmpdir()
    // use command 'au clear-cache' to purge all caches
    transpile = cache(transpile, {name: project.name + '-' + env});
  }

import gulp from 'gulp';
import plumber from 'gulp-plumber';
import babel from 'gulp-babel';
import notify from 'gulp-notify';
import rename from 'gulp-rename';
import cache from 'gulp-cache';
import project from '../aurelia.json';
import {CLIOptions, build, Configuration} from 'aurelia-cli';

let env = CLIOptions.getEnvironment();
const buildOptions = new Configuration(project.build.options);
const useCache = buildOptions.isApplicable('cache');

function configureEnvironment() {
  return gulp.src(`aurelia_project/environments/${env}.js`, {since: gulp.lastRun(configureEnvironment)})
    .pipe(rename('environment.js'))
    .pipe(gulp.dest(project.paths.root));
}

function buildJavaScript() {
  let transpile = babel(project.transpiler.options);
  if (useCache) {
    // the cache directory is "gulp-cache/projName-env" inside folder require('os').tmpdir()
    // use command 'au clear-cache' to purge all caches
    transpile = cache(transpile, {name: project.name + '-' + env});
  }

function configureEnvironment() {
  let env = CLIOptions.getEnvironment();

  return gulp.src(`aurelia_project/environments/${env}.ts`, {since: gulp.lastRun(configureEnvironment)})
    .pipe(rename('environment.ts'))
    .pipe(through.obj(function (file, _, cb) {
      // https://github.com/aurelia/cli/issues/1031
      fs.unlink(`${project.paths.root}/${file.relative}`, function () { cb(null, file); });
    }))
    .pipe(gulp.dest(project.paths.root));
}

function configureEnvironment() {
  let env = CLIOptions.getEnvironment();

  return gulp.src(`aurelia_project/environments/${env}.ts`, { since: gulp.lastRun(configureEnvironment) })
    .pipe(rename('environment.ts'))
    .pipe(through.obj(function (file, _, cb) {
      // https://github.com/aurelia/cli/issues/1031
      fs.unlink(`${project.paths.root}/${file.relative}`, function () { cb(null, file); });
    }))
    .pipe(gulp.dest(project.paths.root));
}

import gulp from 'gulp';
import changedInPlace from 'gulp-changed-in-place';
import plumber from 'gulp-plumber';
import babel from 'gulp-babel';
import sourcemaps from 'gulp-sourcemaps';
import notify from 'gulp-notify';
import rename from 'gulp-rename';
import cache from 'gulp-cache';
import project from '../aurelia.json';
import {CLIOptions, build, Configuration} from 'aurelia-cli';

let env = CLIOptions.getEnvironment();
const buildOptions = new Configuration(project.build.options);
const useCache = buildOptions.isApplicable('cache');

function configureEnvironment() {
  return gulp.src(`aurelia_project/environments/${env}.js`)
    .pipe(changedInPlace({firstPass: true}))
    .pipe(rename('environment.js'))
    .pipe(gulp.dest(project.paths.root));
}

function buildJavaScript() {
  let transpile = babel(project.transpiler.options);
  if (useCache) {
    // the cache directory is "gulp-cache/projName-env" inside folder require('os').tmpdir()
    // use command 'au clear-cache' to purge all caches
    transpile = cache(transpile, {name: project.name + '-' + env});

done();
    });
  }
);

function log(message) {
  console.log(message); //eslint-disable-line no-console
}

function reload() {
  log('Refreshing the browser');
  browserSync.reload();
}

if (CLIOptions.hasFlag('server')) {
  process.env['NODE_ENV'] = CLIOptions.getEnvironment();
  launch.startWebAPI();
}

let run = gulp.series(
  serve,
  done => { watch(reload); done(); }
);

export default run;

function configureEnvironment() {
  let env = CLIOptions.getEnvironment();

  return gulp.src(`aurelia_project/environments/${env}.ts`)
    .pipe(changedInPlace({firstPass:true}))
    .pipe(rename('environment.ts'))
    .pipe(gulp.dest(project.paths.root));
}

import webpackConfig from '../../webpack.config';
import webpack from 'webpack';
import project from '../aurelia.json';
import {CLIOptions, Configuration} from 'aurelia-cli';
import gulp from 'gulp';
import configureEnvironment from './environment';
import del from 'del';

const analyze = CLIOptions.hasFlag('analyze');
const buildOptions = new Configuration(project.build.options);
const production = CLIOptions.getEnvironment() === 'prod';
const server = buildOptions.isApplicable('server');
const extractCss = buildOptions.isApplicable('extractCss');
const coverage = buildOptions.isApplicable('coverage');

const config = webpackConfig({
  production, server, extractCss, coverage, analyze
});
const compiler = webpack(config);

function buildWebpack(done) {
  if (CLIOptions.hasFlag('watch')) {
    compiler.watch({}, onBuild);
  } else {
    compiler.run(onBuild);
    compiler.hooks.done.tap('done', () => done());
  }

function configureEnvironment(): void {
  const env: string = CLIOptions.getEnvironment();

  return gulp.src(`aurelia_project/environments/${env}.ts`)
    .pipe(changedInPlace({firstPass: true}))
    .pipe(rename('environment.ts'))
    .pipe(gulp.dest(project.paths.root));
}