Current script (thx th_pion for base)

github.com/thPion/Screeps-Nooby-Guide

src/role.builder.js

@@ -0,0 +1,60 @@
+var roleUpgrader = require('role.upgrader');
+
+module.exports = {
+    // a function to run the logic for this role
+    /** @param {Creep} creep */
+    run: function (creep) {
+        // if target is defined and creep is not in target room
+        if (creep.memory.target != undefined && creep.room.name != creep.memory.target) {
+            // find exit to target room
+            var exit = creep.room.findExitTo(creep.memory.target);
+            // move to exit
+            creep.moveTo(creep.pos.findClosestByRange(exit));
+            // return the function to not do anything else
+            return;
+        }
+
+        // if creep is trying to complete a constructionSite but has no energy left
+        if (creep.memory.working == true && creep.carry.energy == 0) {
+            var time = creep.memory.ttl - creep.ticksToLive;
+            console.log(creep.name + " : " + creep.memory.role + " > " + time);
+
+            if(creep.ticksToLive < 100) {
+                console.log(creep.name + " suicide for ttl : " + creep.ticksToLive);
+                creep.suicide();
+            }
+            // switch state
+            creep.memory.ttl = creep.ticksToLive;
+            // switch state
+            creep.memory.working = false;
+        }
+        // if creep is harvesting energy but is full
+        else if (creep.memory.working == false && creep.carry.energy == creep.carryCapacity) {
+            // switch state
+            creep.memory.working = true;
+        }
+
+        // if creep is supposed to complete a constructionSite
+        if (creep.memory.working == true) {
+            // find closest constructionSite
+            var constructionSite = creep.pos.findClosestByPath(FIND_CONSTRUCTION_SITES);
+            // if one is found
+            if (constructionSite != undefined) {
+                // try to build, if the constructionSite is not in range
+                if (creep.build(constructionSite) == ERR_NOT_IN_RANGE) {
+                    // move towards the constructionSite
+                    creep.moveTo(constructionSite);
+                }
+            }
+            // if no constructionSite is found
+            else {
+                // go upgrading the controller
+                roleUpgrader.run(creep);
+            }
+        }
+        // if creep is supposed to get energy
+        else {
+            creep.getEnergy(true, true);
+        }
+    }
+};