Add builder pattern

Author: joaofnds

builder-pattern.ts

@@ -0,0 +1,105 @@
+interface RobotPlan {
+  setRobotHead(head: string): void;
+  setRobotTorso(torso: string): void;
+  setRobotArms(arms: string): void;
+  setRobotLegs(legs: string): void;
+}
+
+class Robot implements RobotPlan {
+  private robotHead: string;
+  private robotTorso: string;
+  private robotArms: string;
+  private robotLegs: string;
+
+  public getRobotHead(): string {
+    return this.robotHead;
+  }
+  public setRobotHead(head: string): void {
+    this.robotHead = head;
+  }
+
+  public getRobotTorso(): string {
+    return this.robotTorso;
+  }
+  public setRobotTorso(torso: string): void {
+    this.robotTorso = torso;
+  }
+
+  public getRobotArms(): string {
+    return this.robotArms;
+  }
+  public setRobotArms(arms: string): void {
+    this.robotArms = arms;
+  }
+
+  public getRobotLegs(): string {
+    return this.robotLegs;
+  }
+  public setRobotLegs(legs: string): void {
+    this.robotLegs = legs;
+  }
+}
+
+interface RobotBuilder {
+  buildRobotHead(): void;
+  buildRobotTorso(): void;
+  buildRobotArms(): void;
+  buildRobotLegs(): void;
+  getRobot(): Robot;
+}
+
+class OldRobotBuilder implements RobotBuilder {
+  private robot: Robot;
+
+  public constructor() {
+    this.robot = new Robot();
+  }
+
+  public getRobot(): Robot {
+    return this.robot;
+  }
+
+  public buildRobotHead(): void {
+    this.robot.setRobotHead("Tin Head");
+  }
+  public buildRobotTorso(): void {
+    this.robot.setRobotTorso("Tin Torso");
+  }
+  public buildRobotArms(): void {
+    this.robot.setRobotArms("Tin Arms");
+  }
+  public buildRobotLegs(): void {
+    this.robot.setRobotLegs("Tin Head");
+  }
+}
+
+class RobotEngineer {
+  private robotBuilder: RobotBuilder;
+
+  public constructor(robotBuilder: RobotBuilder) {
+    this.robotBuilder = robotBuilder;
+  }
+
+  public getRobot(): Robot {
+    return this.robotBuilder.getRobot();
+  }
+
+  public makeRobot(): void {
+    this.robotBuilder.buildRobotHead();
+    this.robotBuilder.buildRobotTorso();
+    this.robotBuilder.buildRobotArms();
+    this.robotBuilder.buildRobotLegs();
+  }
+}
+
+// -------------------
+const oldStyleRobot: OldRobotBuilder = new OldRobotBuilder();
+const robotEngineer: RobotEngineer = new RobotEngineer(oldStyleRobot);
+
+robotEngineer.makeRobot();
+const firstRobot: Robot = robotEngineer.getRobot();
+
+console.log("robot head :", firstRobot.getRobotHead());
+console.log("robot torso:", firstRobot.getRobotTorso());
+console.log("robot arms :", firstRobot.getRobotArms());
+console.log("robot legs :", firstRobot.getRobotLegs());