Support for disabling notifications by a Spring Boot property.

Author: k-tomaszewski

README.md

@@ -133,4 +133,11 @@ public class MyConfig {
 }
 ```
 Then you can inject a Spring bean implementing `io.github.k_tomaszewski.notifications.NotificationService` interface, which is the one
-you use for sending notifications.
+you use for sending notifications.
+
+### Disabling notifications
+In certain cases, for example tests, it is handy to have notifications disabled. To disable notifications
+you need to set following Spring Boot property:
+```yaml
+notifications.enabled: false
+```

src/main/java/io/github/k_tomaszewski/notifications/NotificationsConfig.java

@@ -28,7 +28,12 @@ public NotificationsProperties notificationsProperties() {
 
     @Bean
     public NotificationService notificationService(NotificationsProperties config, AutowireCapableBeanFactory beanFactory) {
-        return new NotificationServiceBean(config, createSenders(config), beanFactory);
+        if (config.isEnabled()) {
+            return new NotificationServiceBean(config, createSenders(config), beanFactory);
+        } else {
+            LOG.info("Notifications are disabled by configuration.");
+            return (level, title, content) -> {};
+        }
     }
 
     private static List<? extends Sender>  createSenders(NotificationsProperties config) {

src/main/java/io/github/k_tomaszewski/notifications/NotificationsProperties.java

@@ -19,6 +19,7 @@ public class NotificationsProperties {
 
     private static final String DEFAULT_ENTRY = "default";
 
+    private boolean enabled = true;
     private String emailTo;
     private int queueCapacity = 1000;
     private String sendingStrategyClassName = BasicSendingStrategy.class.getName();
@@ -82,6 +83,14 @@ public void setEmailTo(String emailTo) {
         this.emailTo = emailTo;
     }
 
+    public boolean isEnabled() {
+        return enabled;
+    }
+
+    public void setEnabled(boolean enabled) {
+        this.enabled = enabled;
+    }
+
     @SuppressWarnings("unchecked")
     private static <T> T createInstance(String className, String errorMessageTemplate) {
         try {

src/test/java/io/github/k_tomaszewski/notifications/DisabledNotificationsTet.java

@@ -0,0 +1,24 @@
+package io.github.k_tomaszewski.notifications;
+
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.Test;
+import org.slf4j.event.Level;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.test.context.ActiveProfiles;
+
+@SpringBootTest(classes = NotificationsConfig.class, properties = "notifications.enabled=false")
+@EnableAutoConfiguration
+@ActiveProfiles("test")
+public class DisabledNotificationsTet {
+
+    @Autowired
+    private NotificationService notificationService;
+
+    @Test
+    void shouldProvideNotificationServiceWhenNotificationsDisabled() {
+        Assertions.assertNotNull(notificationService);
+        notificationService.send(Level.INFO, "title", "content");       // and no error
+    }
+}