Use watchify

client.js

@@ -1,7 +1,6 @@
 window.$ = window.jQuery = require("jquery");
 var io = require("socket.io-client");
 var client = require("./src/game-client");
-var config = require("./config.json");
 
 function run(flag) {
 	client.renderer = flag ? require("./src/mode/god") : require("./src/mode/player");

config.json

@@ -1,4 +1,5 @@
 {
+	"dev": true,
 	"port": 8080,
 	"bots": 5,
 	"consts": {

package.json

@@ -4,7 +4,8 @@
 	"description": "An multiplayer-IO type game (cloned from Paper-IO)",
 	"main": "server.js",
 	"scripts": {
-		"build": "browserify client.js | terser > public/js/bundle.js"
+		"build": "browserify client.js | terser > public/js/bundle.js",
+		"build-dev": "watchify client.js -o public/js/bundle.js"
 	},
 	"repository": {
 		"type": "git",
@@ -30,6 +31,7 @@
 	},
 	"devDependencies": {
 		"browserify": "^16.5.0",
-		"terser": "^4.6.3"
+		"terser": "^4.6.3",
+		"watchify": "^3.11.1"
 	}
 }

server.js

@@ -8,8 +8,8 @@ const server = require("http").createServer(app);
 const io = require("socket.io")(server);
 const { exec } = require("child_process");
 
-exec("npm run build");
 var config = require("./config.json");
+config.dev ? exec("npm run build-dev") : exec("npm run build");
 
 if (!(config.port >= 0 && config.port < 65536 && config.port % 1 === 0)) {
 	console.error("[ERROR] `port` argument must be an integer >= 0 and < 65536. Default value will be used.");