1 files changed, 64 insertions, 0 deletions
diff --git a/javatests/com/google/gerrit/metrics/dropwizard/DropWizardReservoirProviderTest.java b/javatests/com/google/gerrit/metrics/dropwizard/DropWizardReservoirProviderTest.java
new file mode 100644
index 0000000000..6402b53ad4
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+++ b/javatests/com/google/gerrit/metrics/dropwizard/DropWizardReservoirProviderTest.java
@@ -0,0 +1,64 @@
+// Copyright (C) 2022 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License 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 com.google.gerrit.metrics.dropwizard;
+
+import static com.google.common.truth.Truth.assertThat;
+import static org.mockito.Mockito.when;
+
+import com.codahale.metrics.ExponentiallyDecayingReservoir;
+import com.codahale.metrics.SlidingTimeWindowArrayReservoir;
+import com.codahale.metrics.SlidingTimeWindowReservoir;
+import com.codahale.metrics.SlidingWindowReservoir;
+import com.codahale.metrics.UniformReservoir;
+import com.google.gerrit.metrics.MetricsReservoirConfig;
+import com.google.gerrit.metrics.ReservoirType;
+import java.time.Duration;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.Mock;
+import org.mockito.junit.MockitoJUnitRunner;
+
+@RunWith(MockitoJUnitRunner.class)
+public class DropWizardReservoirProviderTest {
+  private static final int SLIDING_WINDOW_INTERVAL = 1;
+  private static final int SLIDING_WINDOW_SIZE = 256;
+
+  @Mock private MetricsReservoirConfig configMock;
+
+  @Test
+  public void shouldInstantiateReservoirProviderBasedOnMetricsConfig() {
+    when(configMock.reservoirType()).thenReturn(ReservoirType.ExponentiallyDecaying);
+    assertThat(DropWizardReservoirProvider.get(configMock))
+        .isInstanceOf(ExponentiallyDecayingReservoir.class);
+
+    when(configMock.reservoirType()).thenReturn(ReservoirType.SlidingTimeWindow);
+    when(configMock.reservoirWindow()).thenReturn(Duration.ofMinutes(1));
+    assertThat(DropWizardReservoirProvider.get(configMock))
+        .isInstanceOf(SlidingTimeWindowReservoir.class);
+
+    when(configMock.reservoirType()).thenReturn(ReservoirType.SlidingTimeWindowArray);
+    when(configMock.reservoirWindow()).thenReturn(Duration.ofMinutes(SLIDING_WINDOW_INTERVAL));
+    assertThat(DropWizardReservoirProvider.get(configMock))
+        .isInstanceOf(SlidingTimeWindowArrayReservoir.class);
+
+    when(configMock.reservoirType()).thenReturn(ReservoirType.SlidingWindow);
+    when(configMock.reservoirSize()).thenReturn(SLIDING_WINDOW_SIZE);
+    assertThat(DropWizardReservoirProvider.get(configMock))
+        .isInstanceOf(SlidingWindowReservoir.class);
+
+    when(configMock.reservoirType()).thenReturn(ReservoirType.Uniform);
+    assertThat(DropWizardReservoirProvider.get(configMock)).isInstanceOf(UniformReservoir.class);
+  }
+}