gulpfile.js

/* Gulp file to create dist
*/
var gulp = require("gulp");
var concat = require("gulp-concat");
var minify = require("gulp-minify")
var header = require('gulp-header');

var autoprefixer = require('gulp-autoprefixer');
const cssmin = require('gulp-cssmin');

/* Prevent error for reload */
function swallowError (error) {
  // Show error in the console
  console.log(error.toString())
  this.emit('end')
}

/* Transform ES6 to create the ./dist */
var PluginError = require('plugin-error');
var through = require('through2');

function transform() {
  return through.obj(function(file, encoding, callback) {
    if (file.isNull()) {
        // nothing to do
        return callback(null, file);
    }
    if (file.isStream()) {
        // file.contents is a Stream - https://nodejs.org/api/stream.html
        this.emit('error', new PluginError("BUILD", 'Streams not supported!'));

    } else if (file.isBuffer()) {
      // file content
      content = file.contents.toString();
      if (content) {
        // Prevent ol_has_DEVICE_PIXEL_RATIO
        //content = content.replace(/ol_has_DEVICE_PIXEL_RATIO/g,"ol.has.DEVICE_PIXEL_RATIO");
        // change ol_namespace_Class_Att => ol.namespace.Class.Att
        content = content.replace(/(\bol_([a-z,A-Z]*)_([a-z,A-Z,4]*)_([a-z,A-Z]*)\b)/g,"ol.$2.$3.$4");
        // change ol_namespace_Class => ol.namespace.Class
        content = content.replace(/(\bol_([a-z,A-Z]*)_([a-z,A-Z]*))/g,"ol.$2.$3");
        // change ol_Class => ol.namespace.Class
        content = content.replace(/(\bol_([a-z,A-Z]*))/g,"ol.$2");
        // change var ol.Class => ol.Class
        content = content.replace(/(\bvar ol\.([a-z,A-Z]*))/g,"ol.$2");
        // remove import / export
        content = content.replace(/\bimport (.*)|\bexport (.*)/g,"");
        // remove empty lines
        content = content.replace(/\r/gm, '');
        content = content.replace(/^\s*[\n]/gm, '');
        // let and const => var (for IE)
        content = content.replace(/\blet\b/g, 'var');
        content = content.replace(/\bconst\b/g, 'var');
        // return content
        file.contents = Buffer.from(content);
      }
      return callback(null, file);
    }
  });
};

// Retrieve option (--debug for css)
var name = "ol-games";

// using data from package.json 
var pkg = require('./package.json');
var banner = ['/**',
  ' * <%= pkg.name %> - <%= pkg.description %>',
  ' * @description <%= pkg.keywords %>',
  ' * @version v<%= pkg.version %>',
  ' * @author <%= pkg.author.name %>',
  ' * @see <%= pkg.homepage %>',
  ' * @license <%= pkg.license %>',
  ' */',
  ''].join('\n');

// Build css. Use --debug to build in debug mode
gulp.task('css', function () {
  var css = [
    "./control/*.css",
    "./feature/*.css",
    "./featureanimation/*.css",
    "./game/*.css",
    "./graph/*.css",
    "./media/*.css",
    "./style/*.css", 
    "./utils/*.css"
  ];
  gulp.src(css)
  .pipe(autoprefixer('last 2 versions'))
  .pipe(concat(name+'.css'))
  .pipe(gulp.dest('./dist'));

  gulp.src(css)
  .pipe(autoprefixer('last 2 versions'))
  .pipe(concat(name+'.min.css'))
  .pipe(cssmin())
  .pipe(gulp.dest('./dist'));
});

// Build js
gulp.task("js", function() {
  gulp.src([
    "./control/*.js",
    "./feature/*.js",
    "./featureanimation/*.js",
    "./game/*.js",
    "./graph/*.js",
    "./media/Media.js", "./media/*.js",
    "./source/*.js",
    "./style/*.js", 
    "./utils/*.js"
  ])
  .pipe(transform())
  .pipe(concat(name+".js"))
  .pipe(minify(
    {	ext: { 
        src:".js", 
        min:".min.js" 
      }
    }))
  .on('error', swallowError)
  .pipe(header(banner, { pkg : pkg } ))
  .pipe(gulp.dest("dist"))
  .on('end', function(){ console.log('\x1b[32m','\n>>> Terminated...','\x1b[0m')});
});

/* Watch for modification to recreate the dist */
gulp.task('watch', function() {
  gulp.watch(['*/*.js','*/*.css',"!./dist/*.*"], gulp.series('default'));
});

/* Start a server and watch for modification for live reload */
gulp.task('serve', function() {
  var liveServer = require("live-server");

  var params = {
    port: 8181,             // Set the server port. Defaults to 8080.
    host: "0.0.0.0",        // Set the address to bind to. Defaults to 0.0.0.0 or process.env.IP.
    open: false,            // When false, it won't load your browser by default.
    watch: ['dist','examples'], // comma-separated string for paths to watch
//    ignore: '',             // comma-separated string for paths to ignore
    file: "index.html",     // When set, serve this file (server root relative) for every 404 (useful for single-page applications)
    wait: 1000,             // Waits for all changes, before reloading. Defaults to 0 sec.
    logLevel: 2             // 0 = errors only, 1 = some, 2 = lots
  };
  liveServer.start(params);

  gulp.watch(['*/*','*/*','!dist/*'], gulp.series('default'));
});

/** Build the doc */
gulp.task('doc', function (cb) {
  var jsdoc = require('gulp-jsdoc3');
    var config = require('./doc/jsdoc.json');
    gulp.src([
    "doc/doc.md", "doc/namespace.js",
    "./dist/ol-games.js"
    ], {read: false})
    .pipe(jsdoc(config, cb));
});

// build the dist
gulp.task("dist", gulp.parallel("js","css"));

// The default task that will be run if no task is supplied
gulp.task("default", gulp.parallel("js","css"));