tests for the ViewRegistry

sdk/metrics/src/main/java/io/opentelemetry/sdk/metrics/AggregationChooser.java

@@ -55,7 +55,7 @@ && matchesOnName(descriptor, registeredSelector)) {
     return possibleMatches.get(0).getValue();
   }
 
-  private boolean matchesOne(InstrumentDescriptor descriptor, InstrumentSelector selector) {
+  private static boolean matchesOne(InstrumentDescriptor descriptor, InstrumentSelector selector) {
     if (selector.hasNameRegex() && !matchesOnName(descriptor, selector)) {
       return false;
     }

sdk/metrics/src/main/java/io/opentelemetry/sdk/metrics/Batchers.java

@@ -165,6 +165,66 @@ public final List<MetricData> completeCollectionCycle() {
     public boolean generatesDeltas() {
       return delta;
     }
+
+    @Override
+    public boolean equals(Object o) {
+      if (this == o) {
+        return true;
+      }
+      if (o == null || getClass() != o.getClass()) {
+        return false;
+      }
+
+      AllLabels allLabels = (AllLabels) o;
+
+      if (startEpochNanos != allLabels.startEpochNanos) {
+        return false;
+      }
+      if (delta != allLabels.delta) {
+        return false;
+      }
+      if (descriptor != null ? !descriptor.equals(allLabels.descriptor)
+          : allLabels.descriptor != null) {
+        return false;
+      }
+      if (aggregation != null ? !aggregation.equals(allLabels.aggregation)
+          : allLabels.aggregation != null) {
+        return false;
+      }
+      if (resource != null ? !resource.equals(allLabels.resource) : allLabels.resource != null) {
+        return false;
+      }
+      if (instrumentationLibraryInfo != null ? !instrumentationLibraryInfo
+          .equals(allLabels.instrumentationLibraryInfo)
+          : allLabels.instrumentationLibraryInfo != null) {
+        return false;
+      }
+      if (clock != null ? !clock.equals(allLabels.clock) : allLabels.clock != null) {
+        return false;
+      }
+      if (aggregatorFactory != null ? !aggregatorFactory.equals(allLabels.aggregatorFactory)
+          : allLabels.aggregatorFactory != null) {
+        return false;
+      }
+      return aggregatorMap != null ? aggregatorMap.equals(allLabels.aggregatorMap)
+          : allLabels.aggregatorMap == null;
+    }
+
+    @Override
+    public int hashCode() {
+      int result = descriptor != null ? descriptor.hashCode() : 0;
+      result = 31 * result + (aggregation != null ? aggregation.hashCode() : 0);
+      result = 31 * result + (resource != null ? resource.hashCode() : 0);
+      result =
+          31 * result + (instrumentationLibraryInfo != null ? instrumentationLibraryInfo.hashCode()
+              : 0);
+      result = 31 * result + (clock != null ? clock.hashCode() : 0);
+      result = 31 * result + (aggregatorFactory != null ? aggregatorFactory.hashCode() : 0);
+      result = 31 * result + (aggregatorMap != null ? aggregatorMap.hashCode() : 0);
+      result = 31 * result + (int) (startEpochNanos ^ (startEpochNanos >>> 32));
+      result = 31 * result + (delta ? 1 : 0);
+      return result;
+    }
   }
 
   private Batchers() {}

sdk/metrics/src/main/java/io/opentelemetry/sdk/metrics/ViewRegistry.java

@@ -40,6 +40,10 @@ class ViewRegistry {
     this.aggregationChooser = aggregationChooser;
   }
 
+  void registerView(InstrumentSelector selector, AggregationConfiguration specification) {
+    aggregationChooser.addView(selector, specification);
+  }
+
   /**
    * Create a new {@link io.opentelemetry.sdk.metrics.Batcher} for use in metric recording
    * aggregation.
@@ -62,8 +66,4 @@ Batcher createBatcher(
     }
     throw new IllegalStateException("unsupported Temporality: " + specification.temporality());
   }
-
-  void registerView(InstrumentSelector selector, AggregationConfiguration specification) {
-    aggregationChooser.addView(selector, specification);
-  }
 }

sdk/metrics/src/test/java/io/opentelemetry/sdk/metrics/ViewRegistryTest.java

@@ -0,0 +1,102 @@
+/*
+ * Copyright The OpenTelemetry Authors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package io.opentelemetry.sdk.metrics;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+import io.opentelemetry.sdk.common.InstrumentationLibraryInfo;
+import io.opentelemetry.sdk.internal.TestClock;
+import io.opentelemetry.sdk.metrics.common.InstrumentType;
+import io.opentelemetry.sdk.metrics.common.InstrumentValueType;
+import io.opentelemetry.sdk.metrics.view.AggregationConfiguration;
+import io.opentelemetry.sdk.metrics.view.Aggregations;
+import io.opentelemetry.sdk.metrics.view.InstrumentSelector;
+import io.opentelemetry.sdk.resources.Resource;
+import org.junit.jupiter.api.Test;
+
+class ViewRegistryTest {
+
+  @Test
+  void registerView() {
+    AggregationChooser chooser = mock(AggregationChooser.class);
+
+    ViewRegistry viewRegistry = new ViewRegistry(chooser);
+    InstrumentSelector selector =
+        InstrumentSelector.newBuilder().instrumentType(InstrumentType.COUNTER).build();
+    AggregationConfiguration specification =
+        AggregationConfiguration.create(
+            Aggregations.count(), AggregationConfiguration.Temporality.CUMULATIVE);
+
+    viewRegistry.registerView(selector, specification);
+
+    verify(chooser).addView(selector, specification);
+  }
+
+  @Test
+  void createBatcher_cumulative() {
+    AggregationChooser chooser = mock(AggregationChooser.class);
+
+    ViewRegistry viewRegistry = new ViewRegistry(chooser);
+
+    InstrumentDescriptor descriptor = InstrumentDescriptor.create("name", "description", "unit",
+        InstrumentType.COUNTER, InstrumentValueType.DOUBLE);
+    MeterProviderSharedState providerSharedState = MeterProviderSharedState.create(
+        TestClock.create(),
+        Resource.getEmpty());
+    MeterSharedState meterSharedState = MeterSharedState
+        .create(InstrumentationLibraryInfo.create("test", "1.0"));
+
+    AggregationConfiguration specification =
+        AggregationConfiguration.create(
+            Aggregations.count(), AggregationConfiguration.Temporality.CUMULATIVE);
+    Batcher expectedBatcher = Batchers
+        .getCumulativeAllLabels(descriptor, providerSharedState, meterSharedState,
+            Aggregations.count());
+
+    when(chooser.chooseAggregation(descriptor)).thenReturn(specification);
+
+    Batcher result = viewRegistry.createBatcher(providerSharedState, meterSharedState, descriptor);
+
+    assertThat(result.generatesDeltas()).isFalse();
+    assertThat(result).isEqualTo(expectedBatcher);
+
+    assertThat(result).isNotNull();
+  }
+
+  @Test
+  void createBatcher_delta() {
+    AggregationChooser chooser = mock(AggregationChooser.class);
+
+    ViewRegistry viewRegistry = new ViewRegistry(chooser);
+
+    InstrumentDescriptor descriptor = InstrumentDescriptor.create("name", "description", "unit",
+        InstrumentType.COUNTER, InstrumentValueType.DOUBLE);
+    MeterProviderSharedState providerSharedState = MeterProviderSharedState.create(
+        TestClock.create(),
+        Resource.getEmpty());
+    MeterSharedState meterSharedState = MeterSharedState
+        .create(InstrumentationLibraryInfo.create("test", "1.0"));
+
+    AggregationConfiguration specification =
+        AggregationConfiguration.create(
+            Aggregations.count(), AggregationConfiguration.Temporality.DELTA);
+    Batcher expectedBatcher = Batchers
+        .getDeltaAllLabels(descriptor, providerSharedState, meterSharedState,
+            Aggregations.count());
+
+    when(chooser.chooseAggregation(descriptor)).thenReturn(specification);
+
+    Batcher result = viewRegistry.createBatcher(providerSharedState, meterSharedState, descriptor);
+
+    assertThat(result.generatesDeltas()).isTrue();
+    assertThat(result).isEqualTo(expectedBatcher);
+
+    assertThat(result).isNotNull();
+  }
+}