Assertions refactoring (#1566)

Co-authored-by: Sylvain Juge <763082+SylvainJuge@users.noreply.github.com>

jmx-scraper/src/integrationTest/java/io/opentelemetry/contrib/jmxscraper/assertions/Assertions.java

@@ -0,0 +1,16 @@
+/*
+ * Copyright The OpenTelemetry Authors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package io.opentelemetry.contrib.jmxscraper.assertions;
+
+import io.opentelemetry.proto.metrics.v1.Metric;
+
+/** Dedicated Assertj extension to provide convenient fluent API for metrics testing */
+public class Assertions extends org.assertj.core.api.Assertions {
+
+  public static MetricAssert assertThat(Metric metric) {
+    return new MetricAssert(metric);
+  }
+}

jmx-scraper/src/integrationTest/java/io/opentelemetry/contrib/jmxscraper/assertions/MetricAssert.java

@@ -0,0 +1,330 @@
+/*
+ * Copyright The OpenTelemetry Authors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package io.opentelemetry.contrib.jmxscraper.assertions;
+
+import com.google.errorprone.annotations.CanIgnoreReturnValue;
+import io.opentelemetry.proto.common.v1.KeyValue;
+import io.opentelemetry.proto.metrics.v1.Metric;
+import io.opentelemetry.proto.metrics.v1.NumberDataPoint;
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+import java.util.function.Consumer;
+import java.util.stream.Collectors;
+import org.assertj.core.api.AbstractAssert;
+import org.assertj.core.internal.Integers;
+import org.assertj.core.internal.Iterables;
+import org.assertj.core.internal.Maps;
+import org.assertj.core.internal.Objects;
+
+public class MetricAssert extends AbstractAssert<MetricAssert, Metric> {
+
+  private static final Objects objects = Objects.instance();
+  private static final Iterables iterables = Iterables.instance();
+  private static final Integers integers = Integers.instance();
+  private static final Maps maps = Maps.instance();
+
+  private boolean strict;
+
+  private boolean descriptionChecked;
+  private boolean unitChecked;
+  private boolean typeChecked;
+  private boolean dataPointAttributesChecked;
+
+  MetricAssert(Metric actual) {
+    super(actual, MetricAssert.class);
+  }
+
+  public void setStrict(boolean strict) {
+    this.strict = strict;
+  }
+
+  public void strictCheck() {
+    strictCheck("description", /* expectedCheckStatus= */ true, descriptionChecked);
+    strictCheck("unit", /* expectedCheckStatus= */ true, unitChecked);
+    strictCheck("type", /* expectedCheckStatus= */ true, typeChecked);
+    strictCheck(
+        "data point attributes", /* expectedCheckStatus= */ true, dataPointAttributesChecked);
+  }
+
+  private void strictCheck(
+      String metricProperty, boolean expectedCheckStatus, boolean actualCheckStatus) {
+    if (!strict) {
+      return;
+    }
+    String failMsgPrefix = expectedCheckStatus ? "duplicate" : "missing";
+    info.description(
+        "%s assertion on %s for metric '%s'", failMsgPrefix, metricProperty, actual.getName());
+    objects.assertEqual(info, actualCheckStatus, expectedCheckStatus);
+  }
+
+  /**
+   * Verifies metric description
+   *
+   * @param description expected description
+   * @return this
+   */
+  @CanIgnoreReturnValue
+  public MetricAssert hasDescription(String description) {
+    isNotNull();
+
+    info.description("unexpected description for metric '%s'", actual.getName());
+    objects.assertEqual(info, actual.getDescription(), description);
+    strictCheck("description", /* expectedCheckStatus= */ false, descriptionChecked);
+    descriptionChecked = true;
+    return this;
+  }
+
+  /**
+   * Verifies metric unit
+   *
+   * @param unit expected unit
+   * @return this
+   */
+  @CanIgnoreReturnValue
+  public MetricAssert hasUnit(String unit) {
+    isNotNull();
+
+    info.description("unexpected unit for metric '%s'", actual.getName());
+    objects.assertEqual(info, actual.getUnit(), unit);
+    strictCheck("unit", /* expectedCheckStatus= */ false, unitChecked);
+    unitChecked = true;
+    return this;
+  }
+
+  /**
+   * Verifies the metric is a gauge
+   *
+   * @return this
+   */
+  @CanIgnoreReturnValue
+  public MetricAssert isGauge() {
+    isNotNull();
+
+    info.description("gauge expected for metric '%s'", actual.getName());
+    objects.assertEqual(info, actual.hasGauge(), true);
+    strictCheck("type", /* expectedCheckStatus= */ false, typeChecked);
+    typeChecked = true;
+    return this;
+  }
+
+  @CanIgnoreReturnValue
+  private MetricAssert hasSum(boolean monotonic) {
+    isNotNull();
+
+    info.description("sum expected for metric '%s'", actual.getName());
+    objects.assertEqual(info, actual.hasSum(), true);
+
+    String prefix = monotonic ? "monotonic" : "non-monotonic";
+    info.description(prefix + " sum expected for metric '%s'", actual.getName());
+    objects.assertEqual(info, actual.getSum().getIsMonotonic(), monotonic);
+    return this;
+  }
+
+  /**
+   * Verifies the metric is a counter
+   *
+   * @return this
+   */
+  @CanIgnoreReturnValue
+  public MetricAssert isCounter() {
+    // counters have a monotonic sum as their value can't decrease
+    hasSum(true);
+    strictCheck("type", /* expectedCheckStatus= */ false, typeChecked);
+    typeChecked = true;
+    return this;
+  }
+
+  /**
+   * Verifies the metric is an up-down counter
+   *
+   * @return this
+   */
+  @CanIgnoreReturnValue
+  public MetricAssert isUpDownCounter() {
+    // up down counters are non-monotonic as their value can increase & decrease
+    hasSum(false);
+    strictCheck("type", /* expectedCheckStatus= */ false, typeChecked);
+    typeChecked = true;
+    return this;
+  }
+
+  @CanIgnoreReturnValue
+  public MetricAssert hasDataPointsWithoutAttributes() {
+    isNotNull();
+
+    return checkDataPoints(
+        dataPoints -> {
+          dataPointsCommonCheck(dataPoints);
+
+          // all data points must not have any attribute
+          for (NumberDataPoint dataPoint : dataPoints) {
+            info.description(
+                "no attribute expected on data point for metric '%s'", actual.getName());
+            iterables.assertEmpty(info, dataPoint.getAttributesList());
+          }
+        });
+  }
+
+  @CanIgnoreReturnValue
+  private MetricAssert checkDataPoints(Consumer<List<NumberDataPoint>> listConsumer) {
+    // in practice usually one set of data points is provided but the
+    // protobuf does not enforce that, so we have to ensure checking at least one
+    int count = 0;
+    if (actual.hasGauge()) {
+      count++;
+      listConsumer.accept(actual.getGauge().getDataPointsList());
+    }
+    if (actual.hasSum()) {
+      count++;
+      listConsumer.accept(actual.getSum().getDataPointsList());
+    }
+    info.description("at least one set of data points expected for metric '%s'", actual.getName());
+    integers.assertGreaterThan(info, count, 0);
+
+    strictCheck(
+        "data point attributes", /* expectedCheckStatus= */ false, dataPointAttributesChecked);
+    dataPointAttributesChecked = true;
+    return this;
+  }
+
+  @CanIgnoreReturnValue
+  public MetricAssert hasTypedDataPoints(Collection<String> types) {
+    return checkDataPoints(
+        dataPoints -> {
+          dataPointsCommonCheck(dataPoints);
+
+          Set<String> foundValues = new HashSet<>();
+          for (NumberDataPoint dataPoint : dataPoints) {
+            List<KeyValue> attributes = dataPoint.getAttributesList();
+
+            info.description(
+                "expected exactly one 'name' attribute for typed data point in metric '%s'",
+                actual.getName());
+            iterables.assertHasSize(info, attributes, 1);
+
+            objects.assertEqual(info, attributes.get(0).getKey(), "name");
+            foundValues.add(attributes.get(0).getValue().getStringValue());
+          }
+          info.description(
+              "missing or unexpected type attribute for metric '%s'", actual.getName());
+          iterables.assertContainsExactlyInAnyOrder(info, foundValues, types.toArray());
+        });
+  }
+
+  private void dataPointsCommonCheck(List<NumberDataPoint> dataPoints) {
+    info.description("unable to retrieve data points from metric '%s'", actual.getName());
+    objects.assertNotNull(info, dataPoints);
+
+    // at least one data point must be reported
+    info.description("at least one data point expected for metric '%s'", actual.getName());
+    iterables.assertNotEmpty(info, dataPoints);
+  }
+
+  /**
+   * Verifies that all data points have all the expected attributes
+   *
+   * @param attributes expected attributes
+   * @return this
+   */
+  @SafeVarargs
+  @CanIgnoreReturnValue
+  public final MetricAssert hasDataPointsAttributes(Map.Entry<String, String>... attributes) {
+    return checkDataPoints(
+        dataPoints -> {
+          dataPointsCommonCheck(dataPoints);
+
+          Map<String, String> attributesMap = new HashMap<>();
+          for (Map.Entry<String, String> attributeEntry : attributes) {
+            attributesMap.put(attributeEntry.getKey(), attributeEntry.getValue());
+          }
+          for (NumberDataPoint dataPoint : dataPoints) {
+            Map<String, String> dataPointAttributes = toMap(dataPoint.getAttributesList());
+
+            // all attributes must match
+            info.description(
+                "missing/unexpected data points attributes for metric '%s'", actual.getName());
+            containsExactly(dataPointAttributes, attributes);
+            maps.assertContainsAllEntriesOf(info, dataPointAttributes, attributesMap);
+          }
+        });
+  }
+
+  /**
+   * Verifies that all data points have their attributes match one of the attributes set and that
+   * all provided attributes sets matched at least once.
+   *
+   * @param attributeSets sets of attributes as maps
+   * @return this
+   */
+  @SafeVarargs
+  @CanIgnoreReturnValue
+  @SuppressWarnings("varargs") // required to avoid warning
+  public final MetricAssert hasDataPointsAttributes(Map<String, String>... attributeSets) {
+    return checkDataPoints(
+        dataPoints -> {
+          dataPointsCommonCheck(dataPoints);
+
+          boolean[] matchedSets = new boolean[attributeSets.length];
+
+          // validate each datapoint attributes match exactly one of the provided attributes set
+          for (NumberDataPoint dataPoint : dataPoints) {
+            Map<String, String> map = toMap(dataPoint.getAttributesList());
+
+            int matchCount = 0;
+            for (int i = 0; i < attributeSets.length; i++) {
+              if (mapEquals(map, attributeSets[i])) {
+                matchedSets[i] = true;
+                matchCount++;
+              }
+            }
+
+            info.description(
+                "data point attributes '%s' for metric '%s' must match exactly one of the attribute sets '%s'",
+                map, actual.getName(), Arrays.asList(attributeSets));
+            integers.assertEqual(info, matchCount, 1);
+          }
+
+          // check that all attribute sets matched at least once
+          for (int i = 0; i < matchedSets.length; i++) {
+            info.description(
+                "no data point matched attribute set '%s' for metric '%s'",
+                attributeSets[i], actual.getName());
+            objects.assertEqual(info, matchedSets[i], true);
+          }
+        });
+  }
+
+  /**
+   * Map equality utility
+   *
+   * @param m1 first map
+   * @param m2 second map
+   * @return true if the maps have exactly the same keys and values
+   */
+  private static boolean mapEquals(Map<String, String> m1, Map<String, String> m2) {
+    if (m1.size() != m2.size()) {
+      return false;
+    }
+    return m1.entrySet().stream().allMatch(e -> e.getValue().equals(m2.get(e.getKey())));
+  }
+
+  @SafeVarargs
+  @SuppressWarnings("varargs") // required to avoid warning
+  private final void containsExactly(
+      Map<String, String> map, Map.Entry<String, String>... entries) {
+    maps.assertContainsExactly(info, map, entries);
+  }
+
+  private static Map<String, String> toMap(List<KeyValue> list) {
+    return list.stream()
+        .collect(Collectors.toMap(KeyValue::getKey, kv -> kv.getValue().getStringValue()));
+  }
+}