✅ Complete #27 and Fix #44

Sources/Model/Player.cs

@@ -28,6 +28,15 @@ namespace Model
             Name = name;
         }
 
+        public Player(Player player)
+        {
+            if (player != null)
+            {
+                Name = player.name;
+            }
+            else throw new ArgumentException("you may not make a copy of a null player");
+        }
+
         public override string ToString()
         {
             return Name;

Sources/Model/PlayerManager.cs

@@ -55,10 +55,11 @@ namespace Model
         /// <returns>player with said name</returns>
         public Player GetOneByName(string name)
         {
-            if (!String.IsNullOrEmpty(name))
+            if (!String.IsNullOrWhiteSpace(name) && !name.Equals(""))
             {
-                Player result = players.Where(p => p.Name.Equals(name)).FirstOrDefault();
+                Player result = players.FirstOrDefault(p => p.Name.Equals(name));
-                return new Player(result.Name); // will return null if no such player exists
+                return new Player(result); // THIS IS A COPY (using a copy constructor)
+                // will return null by default if no such player exists
             }
             return null; // we also want ot return null if no name was provided
         }

Sources/Tests/Model_UTs/PlayerManagerTest.cs

@@ -0,0 +1,13 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace Tests.Model_UTs
+{
+    internal class PlayerManagerTest
+    {
+        // TODO test that Player's copy constructer enables isolated changes
+    }
+}

Sources/Tests/Model_UTs/PlayerTest.cs

@@ -26,7 +26,7 @@ namespace Tests.Model_UTs
             Player player;
 
             // Act
-            Action action = () => player = new(" ");
+            void action() => player = new(" ");
 
             // Assert
             Assert.Throws<ArgumentException>(action);
@@ -39,7 +39,7 @@ namespace Tests.Model_UTs
             Player player;
 
             // Act
-            Action action = () => player = new("");
+            void action() => player = new("");
 
             // Assert
             Assert.Throws<ArgumentException>(action);
@@ -50,9 +50,10 @@ namespace Tests.Model_UTs
         {
             // Arrange
             Player player;
+            string name = null;
 
             // Act
-            Action action = () => player = new(null);
+            void action() => player = new Player(name);
 
             // Assert
             Assert.Throws<ArgumentException>(action);
@@ -98,6 +99,23 @@ namespace Tests.Model_UTs
             Assert.False(player.Equals(point));
         }
 
+        [Fact]
+        public void TestGoesThruIfObjIsPlayer()
+        {
+            // Arrange
+            Object p1;
+            Player p2;
+
+            // Act
+            p1 = new Player("Marvin");
+            p2 = new("Clyde");
+
+            // Assert
+            Assert.False(p1.Equals(p2));
+            Assert.False(p2.Equals(p1));
+        }
+
+
         [Fact]
         public void TestEqualsFalseIfNotSameName()
         {
@@ -193,5 +211,34 @@ namespace Tests.Model_UTs
             Assert.True(p1.GetHashCode().Equals(p2.GetHashCode()));
             Assert.True(p2.GetHashCode().Equals(p1.GetHashCode()));
         }
+
+        [Fact]
+        public void TestCopyConstructorExactCopy()
+        {
+            // Arrange
+            Player p1;
+            Player p2;
+
+            // Act
+            p1 = new("Elyse");
+            p2 = new(p1);
+
+            // Assert
+            Assert.True(p1.Equals(p2));
+        }
+
+        [Fact]
+        public void TestCopyConstructorIfNullThenException()
+        {
+            // Arrange
+            Player p1;
+            Player p2 = null;
+
+            // Act
+            void action() => p1 = new Player(p2);
+
+            // Assert
+            Assert.Throws<ArgumentException>(action);
+        }
     }
 }