First working version of new system.

ClassSpawn.js

@@ -6,4 +6,32 @@ module.exports = {
 class _Spawn extends StructureSpawn {
 	init() {
 	}
+
+	requireNewCreep(role) {
+		const roleCount = this.room.find(FIND_MY_CREEPS, {
+			filter: (c) => { return c.memory.role == role; }
+		}).length;
+
+		switch (role) {
+			case ROLE_HARVESTER:
+				return roleCount < 5;
+				break;
+
+			default:
+				break;
+		}
+	}
+
+	createHarvester() {
+		var body = [WORK, CARRY, MOVE];
+		this.createCreep(body, "harvester", ROLE_HARVESTER);
+	}
+
+	createCreep(body, name, role) {
+		if (this.memory.creepCounter == undefined) this.memory.creepCounter = 0;
+		const response = this.spawnCreep(body, name + ": " + this.memory.creepCounter, {
+			memory: { role: role }
+		});
+		if (response == OK) this.memory.creepCounter++;
+	}
 }