added: tests for Watcher, Counter and Counters.

Mage/src/test/java/mage/counters/CountersTest.java

@@ -0,0 +1,98 @@
+package mage.counters;
+
+import org.junit.Before;
+import org.junit.Test;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+public class CountersTest {
+    private Counters counters;
+
+    @Before
+    public void setUp() {
+        counters = new Counters();
+    }
+
+    @Test
+    public void testCopyCounter() {
+        // given
+        counters.addCounter("test", 4);
+
+        // when
+        Counters copy = counters.copy();
+
+        // then
+        int amount = copy.getCount("test");
+        assertEquals(5, amount);
+    }
+
+    @Test
+    public void testRemoveCounter() {
+        // given
+        counters.addCounter("test1", 5);
+        counters.addCounter("test2", 5);
+
+        // when
+
+        //then
+        assertTrue(counters.removeCounter("test1", 6));
+        assertFalse(counters.containsKey("test1"));
+        assertTrue(counters.removeCounter("test2", 2));
+        assertTrue(counters.containsKey("test2"));
+        assertFalse(counters.removeCounter("test3", 5));
+    }
+
+    @Test
+    public void testAddCounterWithNewCounter() {
+        // given
+        counters.addCounter("test1", 5);
+
+        // when
+        counters.addCounter("test1", 10);
+        counters.addCounter("test2", 5);
+
+        // then
+        assertNotEquals(15, counters.getCount("test1"));
+        assertEquals(16, counters.getCount("test1"));
+        assertTrue(counters.containsKey("test2"));
+        assertEquals(6, counters.getCount("test2"));
+    }
+
+    @Test
+    public void testRemoveAllCounter() {
+        // given
+        counters.addCounter("test", 10);
+
+        // when
+        counters.removeAllCounters("test");
+
+        // then
+        assertFalse(counters.containsKey("test"));
+    }
+
+    @Test
+    public void testGetCount() {
+        // given
+        counters.addCounter("test1", 5);
+
+        // when
+        int count1 = counters.getCount("test1");
+        int count2 = counters.getCount("test2");
+
+        // then
+        assertEquals(0, count2);
+        assertEquals(6, count1);
+    }
+
+    @Test
+    public void testContainsKey() {
+        // given
+        counters.addCounter("test1", 5);
+
+        // when
+
+        // then
+        assertTrue(counters.containsKey("test1"));
+        assertFalse(counters.containsKey("test2"));
+    }
+}