Single metrics capture utility

Author: Pankaj Agrawal

powertools-metrics/src/main/java/software/amazon/lambda/powertools/metrics/PowertoolsMetricsLogger.java

@@ -1,11 +1,29 @@
 package software.amazon.lambda.powertools.metrics;
 
+import java.util.function.Consumer;
+
 import software.amazon.cloudwatchlogs.emf.logger.MetricsLogger;
+import software.amazon.cloudwatchlogs.emf.model.Unit;
 
 public final class PowertoolsMetricsLogger {
     private static MetricsLogger metricsLogger = new MetricsLogger();
 
     public static MetricsLogger logger() {
         return metricsLogger;
     }
+
+    public static void withSingleMetric(final String name,
+                                        final double value,
+                                        final Unit unit,
+                                        final String namespace,
+                                        final Consumer<MetricsLogger> logger) {
+        MetricsLogger metricsLogger = new MetricsLogger();
+        try {
+            metricsLogger.setNamespace(namespace);
+            metricsLogger.putMetric(name, value, unit);
+            logger.accept(metricsLogger);
+        } finally {
+            metricsLogger.flush();
+        }
+    }
 }

powertools-metrics/src/test/java/software/amazon/lambda/powertools/metrics/internal/LambdaMetricsAspectTest.java

@@ -15,7 +15,7 @@
 import static org.mockito.ArgumentMatchers.any;
 import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.when;
-import static org.mockito.MockitoAnnotations.initMocks;
+import static org.mockito.MockitoAnnotations.openMocks;
 import static software.amazon.cloudwatchlogs.emf.model.Unit.BYTES;
 
 public class LambdaMetricsAspectTest {
@@ -30,7 +30,7 @@ public class LambdaMetricsAspectTest {
 
     @BeforeEach
     void setUp() throws IllegalAccessException {
-        initMocks(this);
+        openMocks(this);
         setupContext();
         writeStaticField(PowertoolsMetricsLogger.class, "metricsLogger", logger, true);
         requestHandler = new PowertoolsMetricsEnabledHandler();