iluwatar#467 data-bus: DataBusTest: added

Author: kemitix

data-bus/src/test/java/com/iluwatar/databus/DataBusTest.java

@@ -0,0 +1,52 @@
+package com.iluwatar.databus;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.mockito.Mock;
+import org.mockito.MockitoAnnotations;
+
+import static org.mockito.BDDMockito.then;
+import static org.mockito.Mockito.never;
+
+/**
+ * Tests for {@link DataBus}.
+ *
+ * @author Paul Campbell (pcampbell@kemitix.net)
+ */
+public class DataBusTest {
+
+  @Mock
+  private Member member;
+
+  @Mock
+  private DataType event;
+
+  @Before
+  public void setUp() {
+    MockitoAnnotations.initMocks(this);
+  }
+
+  @Test
+  public void publishedEventIsReceivedBySubscribedMember() {
+    //given
+    final DataBus dataBus = DataBus.getInstance();
+    dataBus.subscribe(member);
+    //when
+    dataBus.publish(event);
+    //then
+    then(member).should().accept(event);
+  }
+
+  @Test
+  public void publishedEventIsNotReceivedByMemberAfterUnsubscribing() {
+    //given
+    final DataBus dataBus = DataBus.getInstance();
+    dataBus.subscribe(member);
+    dataBus.unsubscribe(member);
+    //when
+    dataBus.publish(event);
+    //then
+    then(member).should(never()).accept(event);
+  }
+
+}