Update DecoratorPatternTest.java

Author: Deepak-Vohra

core-java-modules/core-java-lang-oop-patterns-2/src/test/java/com/baeldung/overridemethod/decorator/DecoratorPatternTest.java

@@ -8,10 +8,29 @@
 public class DecoratorPatternTest {
 
     @Test
-    void givenACalculator_whenUsingDecoratorWrappingToAddLogging_thenDecoratorWrappingCanBeUsed() {
+    void givenACalculator_whenUsingMeteredDecorator_thenMethodCallsAreCountedCorrectly() {
+        // ARRANGE
         Calculator simpleCalc = new SimpleCalculator();
-        Calculator decoratedCalc = new LoggingCalculatorDecorator(simpleCalc);
-        assertEquals(15, decoratedCalc.add(10, 5));
-        assertEquals(5, decoratedCalc.subtract(10, 5));
+        
+        // Use the MeteredCalculator decorator
+        MeteredCalculator decoratedCalc = new MeteredCalculator(simpleCalc);
+
+        // ACT
+        // Call add twice
+        decoratedCalc.add(10, 5);
+        decoratedCalc.add(2, 3);
+        
+        // Call subtract once
+        decoratedCalc.subtract(10, 5);
+
+        // ASSERT Core Functionality (optional, but good practice)
+        assertEquals(15, decoratedCalc.add(10, 5), "Core functionality must still work.");
+
+        // ASSERT the call counts
+        // 1. Assert 'add' was called 3 times (2 from ACT + 1 from ASSERT Core)
+        assertEquals(3, decoratedCalc.getCallCount("add"), "The 'add' method should have been called 3 times.");
+
+        // 2. Assert 'subtract' was called 1 time
+        assertEquals(1, decoratedCalc.getCallCount("subtract"), "The 'subtract' method should have been called 1 time.");
     }
 }