fix: make sure we always have a Metrics instance

Author: metacosm

operator-framework-core/src/main/java/io/javaoperatorsdk/operator/processing/CustomResourceCache.java

@@ -38,6 +38,9 @@ public CustomResourceCache() {
 
   public CustomResourceCache(ObjectMapper objectMapper, Metrics metrics) {
     this.objectMapper = objectMapper;
+    if (metrics == null) {
+      metrics = Metrics.NOOP;
+    }
     resources = metrics.monitorSizeOf(new ConcurrentHashMap<>(), "cache");
   }
 

operator-framework-core/src/test/java/io/javaoperatorsdk/operator/processing/event/internal/CustomResourceEventSourceTest.java

@@ -10,6 +10,7 @@
 import io.fabric8.kubernetes.client.Watcher;
 import io.fabric8.kubernetes.client.dsl.MixedOperation;
 import io.fabric8.kubernetes.client.dsl.Resource;
+import io.javaoperatorsdk.operator.Metrics;
 import io.javaoperatorsdk.operator.TestUtils;
 import io.javaoperatorsdk.operator.api.config.ConfigurationService;
 import io.javaoperatorsdk.operator.api.config.DefaultControllerConfiguration;
@@ -121,6 +122,7 @@ public TestConfiguration(boolean generationAware) {
           mock(ConfigurationService.class));
       when(getConfigurationService().getObjectMapper())
           .thenReturn(ConfigurationService.OBJECT_MAPPER);
+      when(getConfigurationService().getMetrics()).thenReturn(Metrics.NOOP);
     }
   }
 }