Add tests for MetricUtils

Follow-up on review comment on aws#1882

Author: dagnir

core/sdk-core/src/test/java/software/amazon/awssdk/core/client/AsyncClientHandlerInterceptorExceptionTest.java

@@ -56,7 +56,6 @@
 import software.amazon.awssdk.http.async.AsyncExecuteRequest;
 import software.amazon.awssdk.http.async.SdkAsyncHttpClient;
 import software.amazon.awssdk.http.async.SdkAsyncHttpResponseHandler;
-import software.amazon.awssdk.metrics.MetricCollector;
 import software.amazon.awssdk.utils.CompletableFutureUtils;
 import utils.HttpTestUtils;
 import utils.ValidSdkObjects;

core/sdk-core/src/test/java/software/amazon/awssdk/core/internal/util/MetricUtilsTest.java

@@ -0,0 +1,144 @@
+/*
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License").
+ * You may not use this file except in compliance with the License.
+ * A copy of the License is located at
+ *
+ *  http://aws.amazon.com/apache2.0
+ *
+ * or in the "license" file accompanying this file. This file is distributed
+ * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
+ * express or implied. See the License for the specific language governing
+ * permissions and limitations under the License.
+ */
+
+package software.amazon.awssdk.core.internal.util;
+
+import static org.assertj.core.api.Java6Assertions.assertThat;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.verify;
+import static software.amazon.awssdk.core.client.config.SdkClientOption.METRIC_PUBLISHER;
+
+import java.io.IOException;
+import java.time.Duration;
+import java.util.Optional;
+import org.assertj.core.api.Assertions;
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.rules.ExpectedException;
+import software.amazon.awssdk.core.RequestOverrideConfiguration;
+import software.amazon.awssdk.core.SdkRequestOverrideConfiguration;
+import software.amazon.awssdk.core.client.config.SdkClientConfiguration;
+import software.amazon.awssdk.core.client.config.SdkClientOption;
+import software.amazon.awssdk.core.http.HttpResponseHandler;
+import software.amazon.awssdk.core.metrics.CoreMetric;
+import software.amazon.awssdk.http.SdkHttpFullResponse;
+import software.amazon.awssdk.metrics.MetricCollector;
+import software.amazon.awssdk.metrics.MetricPublisher;
+import software.amazon.awssdk.utils.Pair;
+
+public class MetricUtilsTest {
+    @Rule
+    public ExpectedException thrown = ExpectedException.none();
+
+    @Test
+    public void testMeasureDuration_returnsAccurateDurationInformation() {
+        long testDurationNanos = Duration.ofMillis(1).toNanos();
+
+        Pair<Object, Duration> measuredExecute = MetricUtils.measureDuration(() -> {
+            long start = System.nanoTime();
+            // spin thread instead of Thread.sleep() for a bit more accuracy...
+            while (System.nanoTime() - start < testDurationNanos) {
+            }
+            return "foo";
+        });
+
+        assertThat(measuredExecute.right()).isGreaterThanOrEqualTo(Duration.ofNanos(testDurationNanos));
+    }
+
+    @Test
+    public void testMeasureDuration_returnsCallableReturnValue() {
+        String result = "foo";
+
+        Pair<String, Duration> measuredExecute = MetricUtils.measureDuration(() -> result);
+
+        assertThat(measuredExecute.left()).isEqualTo(result);
+    }
+
+    @Test
+    public void testMeasureDurationUnsafe_doesNotWrapException() throws Exception {
+        IOException ioe = new IOException("boom");
+
+        thrown.expect(IOException.class);
+        try {
+            MetricUtils.measureDurationUnsafe(() -> {
+                throw ioe;
+            });
+        } catch (IOException caught) {
+            assertThat(caught).isSameAs(ioe);
+            throw caught;
+        }
+    }
+
+    @Test
+    public void testMeasureDuration_doesNotWrapException() {
+        RuntimeException e = new RuntimeException("boom");
+
+        thrown.expect(RuntimeException.class);
+
+        try {
+            MetricUtils.measureDuration(() -> {
+                throw e;
+            });
+        } catch (RuntimeException caught) {
+            assertThat(caught).isSameAs(e);
+            throw caught;
+        }
+    }
+
+    @Test
+    public void testCollectHttpMetrics_collectsAllExpectedMetrics() {
+        MetricCollector mockCollector = mock(MetricCollector.class);
+
+        int statusCode = 200;
+        String requestId = "request-id";
+        String amznRequestId = "amzn-request-id";
+        String requestId2 = "request-id-2";
+
+        SdkHttpFullResponse response = SdkHttpFullResponse.builder()
+                .statusCode(statusCode)
+                .putHeader("x-amz-request-id", requestId)
+                .putHeader(HttpResponseHandler.X_AMZN_REQUEST_ID_HEADER, amznRequestId)
+                .putHeader(HttpResponseHandler.X_AMZ_ID_2_HEADER, requestId2)
+                .build();
+
+        MetricUtils.collectHttpMetrics(mockCollector, response);
+
+        verify(mockCollector).reportMetric(CoreMetric.HTTP_STATUS_CODE, statusCode);
+        verify(mockCollector).reportMetric(CoreMetric.AWS_REQUEST_ID, requestId);
+        verify(mockCollector).reportMetric(CoreMetric.AWS_REQUEST_ID, amznRequestId);
+        verify(mockCollector).reportMetric(CoreMetric.AWS_EXTENDED_REQUEST_ID, requestId2);
+
+    }
+
+    @Test
+    public void resolvePublisher_requestConfigNull_ShouldUseSdkClientConfig() {
+        MetricPublisher metricPublisher = mock(MetricPublisher.class);
+
+        SdkClientConfiguration config = SdkClientConfiguration.builder().option(METRIC_PUBLISHER, metricPublisher).build();
+        RequestOverrideConfiguration requestOverrideConfiguration = null;
+        Optional<MetricPublisher> result = MetricUtils.resolvePublisher(config, requestOverrideConfiguration);
+        Assertions.assertThat(result).isEqualTo(Optional.of(metricPublisher));
+    }
+
+    @Test
+    public void resolvePublisher_requestConfigNotNull_shouldTakePrecedence() {
+        MetricPublisher metricPublisher = mock(MetricPublisher.class);
+
+        SdkClientConfiguration config = SdkClientConfiguration.builder().option(METRIC_PUBLISHER, mock(MetricPublisher.class)).build();
+        RequestOverrideConfiguration requestOverrideConfiguration = SdkRequestOverrideConfiguration.builder().metricPublisher(metricPublisher).build();
+        Optional<MetricPublisher> result = MetricUtils.resolvePublisher(config, requestOverrideConfiguration);
+        Assertions.assertThat(result).isEqualTo(Optional.of(metricPublisher));
+    }
+}