#502 Adjusted tests for logger introduction

facade/src/test/java/com/iluwatar/facade/DwarvenGoldmineFacadeTest.java

@@ -22,17 +22,19 @@
  */
 package com.iluwatar.facade;
 
+import ch.qos.logback.classic.Logger;
+import ch.qos.logback.classic.spi.ILoggingEvent;
+import ch.qos.logback.core.AppenderBase;
 import org.junit.After;
 import org.junit.Before;
 import org.junit.Test;
+import org.slf4j.LoggerFactory;
 
-import java.io.PrintStream;
+import java.util.LinkedList;
+import java.util.List;
 
-import static org.mockito.Matchers.eq;
-import static org.mockito.Mockito.mock;
-import static org.mockito.Mockito.verify;
-import static org.mockito.Mockito.verifyNoMoreInteractions;
-import static org.mockito.internal.verification.VerificationModeFactory.times;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
 
 /**
  * Date: 12/9/15 - 9:40 PM
@@ -41,35 +43,19 @@ import static org.mockito.internal.verification.VerificationModeFactory.times;
  */
 public class DwarvenGoldmineFacadeTest {
 
-  /**
-   * The mocked standard out {@link PrintStream}, required since the actions on the gold mine facade
-   * don't have any influence on any other accessible objects, except for writing to std-out using
-   * {@link System#out}
-   */
-  private final PrintStream stdOutMock = mock(PrintStream.class);
+  private InMemoryAppender appender;
 
-  /**
-   * Keep the original std-out so it can be restored after the test
-   */
-  private final PrintStream stdOutOrig = System.out;
-
-  /**
-   * Inject the mocked std-out {@link PrintStream} into the {@link System} class before each test
-   */
   @Before
   public void setUp() {
-    System.setOut(this.stdOutMock);
+    appender = new InMemoryAppender();
   }
 
-  /**
-   * Removed the mocked std-out {@link PrintStream} again from the {@link System} class
-   */
   @After
   public void tearDown() {
-    System.setOut(this.stdOutOrig);
+    appender.stop();
   }
 
-  /**
+   /**
    * Test a complete day cycle in the gold mine by executing all three different steps: {@link
    * DwarvenGoldmineFacade#startNewDay()}, {@link DwarvenGoldmineFacade#digOutGold()} and {@link
    * DwarvenGoldmineFacade#endDay()}.
@@ -82,44 +68,68 @@ public class DwarvenGoldmineFacadeTest {
     goldMine.startNewDay();
 
     // On the start of a day, all workers should wake up ...
-    verify(this.stdOutMock, times(1)).println(eq("Dwarf gold digger wakes up."));
-    verify(this.stdOutMock, times(1)).println(eq("Dwarf cart operator wakes up."));
-    verify(this.stdOutMock, times(1)).println(eq("Dwarven tunnel digger wakes up."));
+    assertTrue(appender.logContains("Dwarf gold digger wakes up."));
+    assertTrue(appender.logContains("Dwarf cart operator wakes up."));
+    assertTrue(appender.logContains("Dwarven tunnel digger wakes up."));
 
     // ... and go to the mine
-    verify(this.stdOutMock, times(1)).println(eq("Dwarf gold digger goes to the mine."));
-    verify(this.stdOutMock, times(1)).println(eq("Dwarf cart operator goes to the mine."));
-    verify(this.stdOutMock, times(1)).println(eq("Dwarven tunnel digger goes to the mine."));
+    assertTrue(appender.logContains("Dwarf gold digger goes to the mine."));
+    assertTrue(appender.logContains("Dwarf cart operator goes to the mine."));
+    assertTrue(appender.logContains("Dwarven tunnel digger goes to the mine."));
 
     // No other actions were invoked, so the workers shouldn't have done (printed) anything else
-    verifyNoMoreInteractions(this.stdOutMock);
+    assertEquals(6, appender.getLogSize());
 
     // Now do some actual work, start digging gold!
     goldMine.digOutGold();
 
     // Since we gave the dig command, every worker should be doing it's job ...
-    verify(this.stdOutMock, times(1)).println(eq("Dwarf gold digger digs for gold."));
-    verify(this.stdOutMock, times(1)).println(eq("Dwarf cart operator moves gold chunks out of the mine."));
-    verify(this.stdOutMock, times(1)).println(eq("Dwarven tunnel digger creates another promising tunnel."));
+    assertTrue(appender.logContains("Dwarf gold digger digs for gold."));
+    assertTrue(appender.logContains("Dwarf cart operator moves gold chunks out of the mine."));
+    assertTrue(appender.logContains("Dwarven tunnel digger creates another promising tunnel."));
 
     // Again, they shouldn't be doing anything else.
-    verifyNoMoreInteractions(this.stdOutMock);
+    assertEquals(9, appender.getLogSize());
 
     // Enough gold, lets end the day.
     goldMine.endDay();
 
     // Check if the workers go home ...
-    verify(this.stdOutMock, times(1)).println(eq("Dwarf gold digger goes home."));
-    verify(this.stdOutMock, times(1)).println(eq("Dwarf cart operator goes home."));
-    verify(this.stdOutMock, times(1)).println(eq("Dwarven tunnel digger goes home."));
+    assertTrue(appender.logContains("Dwarf gold digger goes home."));
+    assertTrue(appender.logContains("Dwarf cart operator goes home."));
+    assertTrue(appender.logContains("Dwarven tunnel digger goes home."));
 
     // ... and go to sleep. We need well rested workers the next day :)
-    verify(this.stdOutMock, times(1)).println(eq("Dwarf gold digger goes to sleep."));
-    verify(this.stdOutMock, times(1)).println(eq("Dwarf cart operator goes to sleep."));
-    verify(this.stdOutMock, times(1)).println(eq("Dwarven tunnel digger goes to sleep."));
+    assertTrue(appender.logContains("Dwarf gold digger goes to sleep."));
+    assertTrue(appender.logContains("Dwarf cart operator goes to sleep."));
+    assertTrue(appender.logContains("Dwarven tunnel digger goes to sleep."));
 
     // Every worker should be sleeping now, no other actions allowed
-    verifyNoMoreInteractions(this.stdOutMock);
+    assertEquals(15, appender.getLogSize());
   }
 
+  private class InMemoryAppender extends AppenderBase<ILoggingEvent> {
+
+    private List<ILoggingEvent> log = new LinkedList<>();
+
+    public InMemoryAppender() {
+      ((Logger) LoggerFactory.getLogger("root")).addAppender(this);
+      start();
+    }
+
+    @Override
+    protected void append(ILoggingEvent eventObject) {
+      log.add(eventObject);
+    }
+
+    public int getLogSize() {
+      return log.size();
+    }
+
+    public boolean logContains(String message) {
+      return log.stream().anyMatch(event -> event.getFormattedMessage().equals(message));
+    }
+  }
+
+
 }