Gulp

This is a task runner

npm install --save-dev gulp 
npm install --save-dev gulp-cli 
npm install --save-dev gulp-webserver 

npm install --save-dev gulp-babel 
npm install --save-dev @babel/core 

?? Babel-polyfill

Create gulpfile.js

var gulp = require("gulp"); 
var rename = require('gulp-rename');  
var webserver = require('gulp-webserver');  

const babel = require('gulp-babel');  

function BuildFiles(done) { 
     gulp.src('index.html')  
       .pipe(gulp.dest('dist'));  

     gulp.src('index.js')  
       .pipe(rename('gulpbundle.js'))  
       .pipe(gulp.dest('dist'))  

   done(); 
}; 

function DevServer(done) { 
     gulp.src('dist')  
       .pipe(webserver({ 
           open: true, 
           port: 8080, 
           fallback: 'index.html'  
    })); 

   done(); 
}; 

exports.DevServer = DevServer; 

/** 
function Run(done) { 
   BuildFiles(); 
   DevServer(); 

   done(); 
}; 
**/ 

exports.default = BuildFiles; 

node ./node_modules/gulp/bin/gulp 
node ./node_modules/gulp/bin/gulp DevServer 

Day 2

var _gulp = require("gulp"); 
var _rename = require('gulp-rename');  
var _notify = require('gulp-notify');  
var _webserver = require('gulp-webserver');  
var _browserSync = require("browser-sync").create(); 
// var _babel = require('gulp-babel');  


_gulp.task('BuildFiles', function f_BuildFiles(done) {  
   _gulp.src('index.html')  
      .pipe(_gulp.dest('dist'));  

   _gulp.src('index.js')  
      .pipe(_rename('gulpbundle.js'))  
      .pipe(_gulp.dest('dist'))  

   done(); 
}); 

_gulp.task("watch", _gulp.parallel(f_BrowserSync, f_WatchFiles)) 

// function f_DevServer(done) { 
//    _gulp.src('dist')  
//       .pipe(_webserver({ 
//          open: false, 
//          port: 8080, 
//          fallback: 'index.html'  
//       })); 

//    done(); 
// }; 

function f_BrowserSync() { 
   _browserSync.init({ 
      server: { 
         baseDir: 'dist'  
      } 
   }); 
} 

function f_WatchFiles() { 
   //_gulp.watch(jsWatch, _gulp.series(js, _browserSync.reload)); 
   _gulp.watch('*.js', _gulp.series(f_JSFiles, f_Reload));  
   _gulp.watch('*.html', _gulp.series(f_HTMLFiles, f_Reload));  

   // _gulp.src('index.js')  
   //    .pipe( _notify({ message: 'Gulp is Watching' })); 
} 

function f_JSFiles(done) { 
   _gulp.src('index.js')  
      .pipe(_rename('gulpbundle.js'))  
      .pipe(_gulp.dest('dist'))  

   done(); 
} 

function f_HTMLFiles(done) { 
   _gulp.src('index.html')  
      .pipe(_gulp.dest('dist'));  

   done(); 
} 

function f_Reload(done) { 
   _browserSync.reload(); 
   done(); 
} 

node ./node_modules/gulp/bin/gulp BuildFiles 
node ./node_modules/gulp/bin/gulp watch