Use property to retrieve balance in bank-account exercise (#192)

Author: ErikSchierboom

exercises/bank-account/BankAccountTest.cs

@@ -11,7 +11,7 @@ public void Returns_empty_balance_after_opening()
         var account = new BankAccount();
         account.Open();
 
-        Assert.That(account.GetBalance(), Is.EqualTo(0));
+        Assert.That(account.Balance, Is.EqualTo(0));
     }
 
     [Ignore("Remove to run test")]
@@ -21,10 +21,10 @@ public void Check_basic_balance()
         var account = new BankAccount();
         account.Open();
 
-        var openingBalance = account.GetBalance();
+        var openingBalance = account.Balance;
 
         account.UpdateBalance(10);
-        var updatedBalance = account.GetBalance();
+        var updatedBalance = account.Balance;
 
         Assert.That(openingBalance, Is.EqualTo(0));
         Assert.That(updatedBalance, Is.EqualTo(10));
@@ -36,13 +36,13 @@ public void Balance_can_increment_and_decrement()
     {
         var account = new BankAccount();
         account.Open();
-        var openingBalance = account.GetBalance();
+        var openingBalance = account.Balance;
 
         account.UpdateBalance(10);
-        var addedBalance = account.GetBalance();
+        var addedBalance = account.Balance;
 
         account.UpdateBalance(-15);
-        var subtractedBalance = account.GetBalance();
+        var subtractedBalance = account.Balance;
 
         Assert.That(openingBalance, Is.EqualTo(0));
         Assert.That(addedBalance, Is.EqualTo(10));
@@ -57,7 +57,7 @@ public void Closed_account_throws_exception_when_checking_balance()
         account.Open();
         account.Close();
 
-        Assert.Throws<InvalidOperationException>(() => account.GetBalance());
+        Assert.That(() => account.Balance, Throws.InvalidOperationException);
     }
 
     [Ignore("Remove to run test")]
@@ -84,6 +84,6 @@ public void Change_account_balance_from_multiple_threads()
         }
         Task.WaitAll(tasks.ToArray());
 
-        Assert.That(account.GetBalance(), Is.EqualTo(0));
+        Assert.That(account.Balance, Is.EqualTo(0));
     }
 }

exercises/bank-account/Example.cs

@@ -23,16 +23,19 @@ public void Close()
         }
     }
 
-    public float GetBalance()
+    public float Balance
     {
-        lock(_lock)
+        get
         {
-            if (!isOpen)
+            lock (_lock)
             {
-                throw new InvalidOperationException("Cannot get balance on an account that isn't open");
-            }
+                if (!isOpen)
+                {
+                    throw new InvalidOperationException("Cannot get balance on an account that isn't open");
+                }
 
-            return balance;
+                return balance;
+            }
         }
     }