optimized board class + added 1 test that fucking doesn't work

Qwirkle/QwirkleClassLibrary/Board.cs

@@ -3,7 +3,6 @@ using System.Collections.Generic;
 using System.Linq;
 using System.Text;
 using System.Threading.Tasks;
-// ReSharper disable All
 
 namespace QwirkleClassLibrary
 {
@@ -31,16 +30,7 @@ namespace QwirkleClassLibrary
             {
                 if (this.Cells[i].GetX == x && this.Cells[i].GetY == y)
                 {
-                    if (Cells[i].IsFree == true)
-                    {
-                        return Cells[i].SetTile(tile);
-
-                    }
-                    else
-                    {
-                        return false;
-                    }
-
+                    return Cells[i].IsFree == false && Cells[i].SetTile(tile);
                 }
             }
             return false;

Qwirkle/QwirkleClassLibrary/Cell.cs

@@ -11,6 +11,11 @@ public class Cell
 
     public Cell(int x, int y)
     {
+        if (this.x < 0 || this.y < 0)
+        {
+            throw new ArgumentException("");
+        }
+        
         this.x = x;
         this.y = y;
     }

Qwirkle/TestBase/TestCell.cs

@@ -0,0 +1,21 @@
+using QwirkleClassLibrary;
+namespace TestBase;
+
+public class TestCell
+{
+    [Theory]
+    [InlineData(true, 10, 20, 10, 20)]
+    [InlineData(false, -10, 20, -10, 20)]
+    
+    public void Test_CellConstructor(bool isValid, int expectedX, int expectedY, int x, int y)
+    {
+        if (!isValid)
+        {
+            Assert.Throws<ArgumentException>(() => new Cell(x, y));
+        }
+
+        Cell c = new Cell(x, y);
+        Assert.Equal(expectedX, x);
+        Assert.Equal(expectedY, y);
+    }
+}