fix(health): fix null exception when DOWN (#160)

Author: juancgalvis

starters/async-commons-starter/src/main/java/org/reactivecommons/async/starter/config/health/RCHealthIndicator.java

@@ -5,9 +5,13 @@
 public abstract class RCHealthIndicator {
 
     public Mono<RCHealth> health() {
-        return doHealthCheck(RCHealth.builder())
+        var builder = RCHealth.builder();
+        return doHealthCheck(builder)
                 .onErrorResume(e ->
-                        Mono.just(RCHealth.builder().down().withDetail("error", e.getMessage()).build())
+                        Mono.just(builder
+                                .down()
+                                .withDetail("error", e.getMessage())
+                                .build())
                 );
     }
 

starters/async-commons-starter/src/main/java/org/reactivecommons/async/starter/config/health/ReactiveCommonsHealthIndicator.java

@@ -14,6 +14,7 @@
 public class ReactiveCommonsHealthIndicator extends AbstractReactiveHealthIndicator {
     public static final String DOMAIN = "domain";
     public static final String VERSION = "version";
+    public static final String UNKNOWN = "unknown";
     private final ConnectionManager manager;
 
     @Override
@@ -29,7 +30,7 @@ protected Mono<Health> doHealthCheck(Health.Builder builder) {
     }
 
     private Health.Builder reduceHealth(Health.Builder builder, RCHealth health) {
-        String domain = health.details().get(DOMAIN).toString();
+        String domain = health.details().getOrDefault(DOMAIN, UNKNOWN).toString();
         if (health.status().equals(RCHealth.Status.DOWN)) {
             log.error("Broker of domain {} is down", domain);
             return builder.down().withDetail(domain, health.details());

starters/async-commons-starter/src/test/java/org/reactivecommons/async/starter/config/health/ReactiveCommonsHealthIndicatorTest.java

@@ -71,4 +71,17 @@ void shouldBeDown() {
                 .expectNextMatches(health -> health.getStatus().toString().equals("DOWN"))
                 .verifyComplete();
     }
+
+    @Test
+    void shouldBeDownAndSetDomain() {
+        // Arrange
+        when(brokerProvider.healthCheck()).thenReturn(Mono.just(RCHealth.builder().down().build()));
+        when(brokerProvider2.healthCheck()).thenReturn(Mono.just(RCHealth.builder().up().build()));
+        // Act
+        Mono<Health> flow = healthIndicator.health();
+        // Assert
+        StepVerifier.create(flow)
+                .expectNextMatches(health -> health.getStatus().toString().equals("DOWN"))
+                .verifyComplete();
+    }
 }