Lab 9: Prototype Pattern

Objectives

During this lab session:

Students will modify and/or extend C# code that implements the Prototype pattern.

This activity helps the student develop the following skills, values and attitudes: ability to analyze and synthesize, capacity for identifying and solving problems, and efficient use of computer systems.

Activity Description

This lab can be developed individually or in pairs.

Make a new folder called prototype. Place all the files you create in this folder.

Read section 5.1 of [BISHOP] in order to understand what the Prototype Pattern is, and how it can be correctly implemented using C#.

You are given the following definition, which represents a Clone Trooper class from the Star Wars saga:

namespace PrototypePattern {
    
    using System;
    using System.Collections;
    using System.Collections.Generic;
    
    [Serializable()]
    public class CloneTrooper: IEquatable<CloneTrooper>,
            IEnumerable<CloneTrooper> {
        
        List<CloneTrooper> list = new List<CloneTrooper>();
        public string Name { get; set; }
        
        public CloneTrooper(string name) {
            Name = name;
        }
        
        public override string ToString() {
            return Name;        
        }
        
        public override bool Equals(object other) {
            if (!(other is CloneTrooper)) {
                return false;
            } 
            return Equals((CloneTrooper) other);
        }
        
        public bool Equals(CloneTrooper other) {
            return Name.Equals(other.Name);
        }
        
        public override int GetHashCode() {
            return Name.GetHashCode();
        }
        
        public void AddSubordinate(CloneTrooper cloneTrooper) {
            list.Add(cloneTrooper);                
        }
        
        public IEnumerator<CloneTrooper> GetEnumerator() {
            return list.GetEnumerator();
        }
        
        IEnumerator IEnumerable.GetEnumerator() {
            return GetEnumerator();
        }                
    }    
}

Modify the above code in whatever way you deem necessary so that the CloneTrooper class supports the Prototype design pattern via two methods: Clone and DeepClone.

Make sure the code that you write behaves exactly as expected by the following unit tests:

namespace PrototypePattern {
    using NUnit.Framework;
    
    [TestFixture]
    public class TestPrototype {
        
        CloneTrooper ct1, ct2, ct3, ct4;
               
        [SetUp]
        public void Init() {
            ct1 = new CloneTrooper("Cody");
            ct2 = new CloneTrooper("Bly");
            ct3 = new CloneTrooper("Thire");
            ct4 = new CloneTrooper("Keller");            
            ct1.AddSubordinate(ct2);
            ct1.AddSubordinate(ct3);
            ct1.AddSubordinate(ct4);
            ct4.AddSubordinate(ct1);  // OMG, a circular reference!
        }
        
        [Test]
        public void TestCloneTrooperSimple() {
            
            Assert.AreEqual("Cody", ct1.Name);
            Assert.AreEqual("Bly", ct2.Name);
            Assert.AreEqual("Cody", ct1.ToString());
            Assert.AreEqual("Bly", ct2.ToString());
            
            Assert.AreEqual(ct1, ct1);             
            Assert.AreSame(ct1, ct1);

            var other = new CloneTrooper("Cody");
                        
            Assert.AreEqual(ct1, other);
            Assert.AreEqual(ct1.GetHashCode(), other.GetHashCode());
            Assert.AreNotSame(ct1, other);
            Assert.AreNotEqual(ct1, ct2);
            Assert.AreNotEqual(ct1, "Cody");            
        }
        
        [Test]
        public void TestCloneTrooperClone() {
            
            var clone = ct1.Clone();
            
            Assert.AreEqual(ct1, clone);
            Assert.AreNotSame(ct1, clone);
            
            var enum1 = clone.GetEnumerator();
            
            Assert.IsTrue(enum1.MoveNext());
            Assert.AreSame(ct2, enum1.Current);
            
            Assert.IsTrue(enum1.MoveNext());
            Assert.AreSame(ct3, enum1.Current);
            
            Assert.IsTrue(enum1.MoveNext());
            Assert.AreSame(ct4, enum1.Current);
            
            var enum2 = enum1.Current.GetEnumerator();
                                 
            Assert.IsTrue(enum2.MoveNext());
            Assert.AreSame(ct1, enum2.Current);
            
            Assert.IsFalse(enum2.MoveNext());
            Assert.IsFalse(enum1.MoveNext());
        }
        
        [Test]
        public void TestCloneTrooperDeepCopy() {
            
            var clone = ct1.DeepCopy();
            
            Assert.AreEqual(ct1, clone);
            Assert.AreNotSame(ct1, clone);
            
            var enum1 = clone.GetEnumerator();
            
            Assert.IsTrue(enum1.MoveNext());
            Assert.AreEqual(ct2, enum1.Current);
            Assert.AreNotSame(ct2, enum1.Current);
            
            Assert.IsTrue(enum1.MoveNext());
            Assert.AreEqual(ct3, enum1.Current);
            Assert.AreNotSame(ct3, enum1.Current);
            
            Assert.IsTrue(enum1.MoveNext());
            Assert.AreEqual(ct4, enum1.Current);
            Assert.AreNotSame(ct4, enum1.Current);
            
            var enum2 = enum1.Current.GetEnumerator();
            
            Assert.IsTrue(enum2.MoveNext());
            Assert.AreEqual(ct1, enum2.Current);
            Assert.AreNotSame(ct1, enum2.Current);
            Assert.AreSame(clone, enum2.Current);
            
            Assert.IsFalse(enum2.MoveNext());
            Assert.IsFalse(enum1.MoveNext());
        }
    }    
}

Deliverables

To hand in your lab work, follow these instructions:

Create a readme.txt text file that includes the name and student ID of the authors. Copy this file to the prototype folder.
Create a ZIP file with the full contents of the prototype directory. Call this file prototype.zip.
Using the Online Assignment Delivery System (SETA), deliver the ZIP file. Due date is Monday, April 13.

Evaluation

This activity will be evaluated using the following criteria:

100	The code works as requested.
60-90	The code works, but has some flaws.
20-50	The code doesn't work, but it seams that some amount of time was spent on it.
DA	The program was plagiarized.

Software Design and Architecture

Lab 9: Prototype Pattern

Objectives

Activity Description

Deliverables

Evaluation