diff --git a/pom.xml b/pom.xml
index 9ed37aa..69688d2 100644
--- a/pom.xml
+++ b/pom.xml
@@ -108,15 +108,12 @@
                                                         </rule>
                                                 </rules>
                                                 <excludes>
-                                                        <exclude>**/*ExampleRunner*</exclude>
                                                         <exclude>**/AppCommandLineRunner*</exclude>
                                                         <exclude>**/ExamplesCommandLineRunner*</exclude>
                                                         <exclude>**/ProducerConsumerExampleRunner*</exclude>
                                                         <exclude>**/Consumer*</exclude>
                                                         <exclude>**/JavaPatternsAndConstructsApplication*</exclude>
                                                         <exclude>**/MainWindow*</exclude>
-                                                        <exclude>**/Messages*</exclude>
-                                                        <exclude>**/ApplicationProperties*</exclude>
                                                         <exclude>**/HyperlinkMouseListener*</exclude>
                                                         <exclude>**/ObservableAbstract*</exclude>
                                                 </excludes>
diff --git a/src/main/java/com/penapereira/example/constructs/producerconsumer/Producer.java b/src/main/java/com/penapereira/example/constructs/producerconsumer/Producer.java
index 20e174a..8295a34 100644
--- a/src/main/java/com/penapereira/example/constructs/producerconsumer/Producer.java
+++ b/src/main/java/com/penapereira/example/constructs/producerconsumer/Producer.java
@@ -16,6 +16,8 @@ public void run() {
 			try {
 				queue.put(i);
 			} catch (InterruptedException finish) {
+				Thread.currentThread().interrupt();
+				return;
 			}
 		}
 	}
diff --git a/src/test/java/com/penapereira/example/constructs/app/ui/GuiAppenderTests.java b/src/test/java/com/penapereira/example/constructs/app/ui/GuiAppenderTests.java
index 4d58ec2..dc2b178 100644
--- a/src/test/java/com/penapereira/example/constructs/app/ui/GuiAppenderTests.java
+++ b/src/test/java/com/penapereira/example/constructs/app/ui/GuiAppenderTests.java
@@ -1,10 +1,14 @@
 package com.penapereira.example.constructs.app.ui;
 
 import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertTrue;
 
 import java.awt.EventQueue;
 
 import org.junit.jupiter.api.Test;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 import ch.qos.logback.classic.Level;
 import ch.qos.logback.classic.spi.LoggingEvent;
@@ -25,4 +29,21 @@ void appendsMessageToOutputSink() throws Exception {
 
         assertEquals("test message" + System.lineSeparator(), output.toString());
     }
+
+    @Test
+    void attachesItselfToRootLoggerWhenInitialized() throws Exception {
+        GuiAppender appender = new GuiAppender(text -> {});
+        ch.qos.logback.classic.Logger root = (ch.qos.logback.classic.Logger) LoggerFactory
+                .getLogger(Logger.ROOT_LOGGER_NAME);
+        assertFalse(root.isAttached(appender));
+        try {
+            appender.afterPropertiesSet();
+
+            assertTrue(appender.isStarted());
+            assertTrue(root.isAttached(appender));
+        } finally {
+            root.detachAppender(appender);
+            appender.stop();
+        }
+    }
 }
diff --git a/src/test/java/com/penapereira/example/constructs/chainofresponsibility/ChainTests.java b/src/test/java/com/penapereira/example/constructs/chainofresponsibility/ChainTests.java
index ae4b36d..cf59a14 100644
--- a/src/test/java/com/penapereira/example/constructs/chainofresponsibility/ChainTests.java
+++ b/src/test/java/com/penapereira/example/constructs/chainofresponsibility/ChainTests.java
@@ -17,4 +17,21 @@ void chainProcessesNumbers() {
         assertEquals("zero", negative.handle(0));
         assertEquals("positive", negative.handle(5));
     }
+
+    @Test
+    void requestNobodyHandlesIsReportedAsUnhandled() {
+        Handler negative = new NegativeHandler();
+        Handler zero = new ZeroHandler();
+        negative.setNext(zero);
+
+        assertEquals("unhandled", negative.handle(5));
+    }
+
+    @Test
+    void lastHandlerWithoutNextReturnsUnhandled() {
+        Handler positive = new PositiveHandler();
+
+        assertEquals("positive", positive.handle(1));
+        assertEquals("unhandled", positive.handle(-1));
+    }
 }
diff --git a/src/test/java/com/penapereira/example/constructs/factory/FactoryTests.java b/src/test/java/com/penapereira/example/constructs/factory/FactoryTests.java
index e77b299..7186594 100644
--- a/src/test/java/com/penapereira/example/constructs/factory/FactoryTests.java
+++ b/src/test/java/com/penapereira/example/constructs/factory/FactoryTests.java
@@ -12,4 +12,11 @@ void factoryCreatesConcreteProducts() {
         assertEquals("Concrete Product A", a.name());
         assertEquals("Concrete Product B", b.name());
     }
+
+    @Test
+    void factoryRejectsUnknownType() {
+        ProductFactory factory = new ProductFactory();
+        IllegalArgumentException ex = assertThrows(IllegalArgumentException.class, () -> factory.createProduct("C"));
+        assertEquals("Unknown type: C", ex.getMessage());
+    }
 }
diff --git a/src/test/java/com/penapereira/example/constructs/producerconsumer/ProducerTests.java b/src/test/java/com/penapereira/example/constructs/producerconsumer/ProducerTests.java
index f95e11e..6267953 100644
--- a/src/test/java/com/penapereira/example/constructs/producerconsumer/ProducerTests.java
+++ b/src/test/java/com/penapereira/example/constructs/producerconsumer/ProducerTests.java
@@ -20,4 +20,21 @@ void producerAddsElements() throws InterruptedException {
         assertEquals(2, queue.take());
         assertEquals(3, queue.take());
     }
+
+    @Test
+    void producerStopsWhenInterrupted() throws InterruptedException {
+        BlockingQueue<Integer> queue = new LinkedBlockingDeque<>(1);
+        Thread t = new Thread(new Producer(queue));
+        t.start();
+        while (queue.isEmpty()) {
+            Thread.onSpinWait();
+        }
+
+        t.interrupt();
+        t.join(5_000);
+
+        assertFalse(t.isAlive());
+        assertEquals(1, queue.size());
+        assertEquals(1, queue.take());
+    }
 }