Auto reload your Go webserver with Gulp

Gulpfile.js

const gulp     = require('gulp'),
      util     = require('gulp-util'),
      notifier = require('node-notifier'),
      sync     = require('gulp-sync')(gulp).sync,
      reload   = require('gulp-livereload'),
      child    = require('child_process'),
      os       = require('os');

var server = null;


// Compile application
gulp.task('server:build', function() {

  // Build application in the "gobin" folder
  var build = child.spawnSync('go', ['install']);

  if (build.stderr.length) {
    util.log(util.colors.red('Something wrong with this version :'));
    var lines = build.stderr.toString()
      .split('\n').filter(function(line) {
        return line.length
      });
    for (var l in lines)
      util.log(util.colors.red(
        'Error (go install): ' + lines[l]
      ));
    notifier.notify({
      title: 'Error (go install)',
      message: lines
    });
  }

  return build;

});


// Server launch
gulp.task('server:spawn', function() {

  // Stop the server
  if (server && server !== 'null') {
    server.kill();
  }

  // Application name
  if (os.platform() == 'win32') {
    // Windows
    var path_folder = __dirname.split('\\');
  } else {
    // Linux / MacOS
    var path_folder = __dirname.split('/');
  }
  var length = path_folder.length;
  var app    = path_folder[length - parseInt(1)];

  // Run the server
  if (os.platform() == 'win32') {
    server = child.spawn(app + '.exe');
  } else {
    server = child.spawn(app);
  }

  // Display terminal informations
  server.stderr.on('data', function(data) {
    process.stdout.write(data.toString());
  });

});


// Watch files
gulp.task('server:watch', function() {

  gulp.watch([
    '*.go',
    '**/*.go',
  ], sync([
    'server:build',
    'server:spawn'
  ], 'server'));

});


gulp.task('default', ['server:build', 'server:spawn', 'server:watch']);

In case someone is trying to convert this to gulp 4: https://gist.github.com/quantonganh/ee8ee0e2c9576acdcbfc56fd627ad07e