1 files changed, 226 insertions, 0 deletions
diff --git a/api/src/test/java/io/opencensus/metrics/DistributionTest.java b/api/src/test/java/io/opencensus/metrics/DistributionTest.java
new file mode 100644
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--- /dev/null
+++ b/api/src/test/java/io/opencensus/metrics/DistributionTest.java
@@ -0,0 +1,226 @@
+/*
+ * Copyright 2018, OpenCensus Authors
+ *
+ * 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 io.opencensus.metrics;
+
+import static com.google.common.truth.Truth.assertThat;
+
+import com.google.common.testing.EqualsTester;
+import io.opencensus.common.Timestamp;
+import io.opencensus.metrics.Distribution.Bucket;
+import io.opencensus.metrics.Distribution.Exemplar;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.List;
+import java.util.Map;
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.rules.ExpectedException;
+import org.junit.runner.RunWith;
+import org.junit.runners.JUnit4;
+
+/** Unit tests for {@link Value}. */
+@RunWith(JUnit4.class)
+public class DistributionTest {
+
+  @Rule public final ExpectedException thrown = ExpectedException.none();
+
+  private static final Timestamp TIMESTAMP = Timestamp.create(1, 0);
+  private static final Map<String, String> ATTACHMENTS = Collections.singletonMap("key", "value");
+
+  @Test
+  public void createAndGet_Bucket() {
+    Bucket bucket = Bucket.create(98);
+    assertThat(bucket.getCount()).isEqualTo(98);
+    assertThat(bucket.getExemplar()).isNull();
+  }
+
+  @Test
+  public void createAndGet_BucketWithExemplar() {
+    Exemplar exemplar = Exemplar.create(12.2, TIMESTAMP, ATTACHMENTS);
+    Bucket bucket = Bucket.create(7, exemplar);
+    assertThat(bucket.getCount()).isEqualTo(7);
+    assertThat(bucket.getExemplar()).isEqualTo(exemplar);
+  }
+
+  @Test
+  public void createBucket_preventNullExemplar() {
+    thrown.expect(NullPointerException.class);
+    thrown.expectMessage("exemplar");
+    Bucket.create(1, null);
+  }
+
+  @Test
+  public void createAndGet_Exemplar() {
+    Exemplar exemplar = Exemplar.create(-9.9, TIMESTAMP, ATTACHMENTS);
+    assertThat(exemplar.getValue()).isEqualTo(-9.9);
+    assertThat(exemplar.getTimestamp()).isEqualTo(TIMESTAMP);
+    assertThat(exemplar.getAttachments()).isEqualTo(ATTACHMENTS);
+  }
+
+  @Test
+  public void createAndGet_Distribution() {
+    Exemplar exemplar = Exemplar.create(15.0, TIMESTAMP, ATTACHMENTS);
+    List<Double> bucketBounds = Arrays.asList(-1.0, 0.0, 1.0);
+    List<Bucket> buckets =
+        Arrays.asList(
+            Bucket.create(3), Bucket.create(1), Bucket.create(2), Bucket.create(4, exemplar));
+    Distribution distribution = Distribution.create(6.6, 10, 678.54, bucketBounds, buckets);
+    assertThat(distribution.getMean()).isEqualTo(6.6);
+    assertThat(distribution.getCount()).isEqualTo(10);
+    assertThat(distribution.getSumOfSquaredDeviations()).isEqualTo(678.54);
+    assertThat(distribution.getBucketBoundaries())
+        .containsExactlyElementsIn(bucketBounds)
+        .inOrder();
+    assertThat(distribution.getBuckets()).containsExactlyElementsIn(buckets).inOrder();
+  }
+
+  @Test
+  public void createBucket_NegativeCount() {
+    thrown.expect(IllegalArgumentException.class);
+    thrown.expectMessage("bucket count should be non-negative.");
+    Bucket.create(-5);
+  }
+
+  @Test
+  public void createExemplar_PreventNullAttachments() {
+    thrown.expect(NullPointerException.class);
+    thrown.expectMessage("attachments");
+    Exemplar.create(15, TIMESTAMP, null);
+  }
+
+  @Test
+  public void createExemplar_PreventNullAttachmentKey() {
+    Map<String, String> attachments = Collections.singletonMap(null, "value");
+    thrown.expect(NullPointerException.class);
+    thrown.expectMessage("key of attachment");
+    Exemplar.create(15, TIMESTAMP, attachments);
+  }
+
+  @Test
+  public void createExemplar_PreventNullAttachmentValue() {
+    Map<String, String> attachments = Collections.singletonMap("key", null);
+    thrown.expect(NullPointerException.class);
+    thrown.expectMessage("value of attachment");
+    Exemplar.create(15, TIMESTAMP, attachments);
+  }
+
+  @Test
+  public void createDistribution_NegativeCount() {
+    List<Double> bucketBounds = Arrays.asList(-1.0, 0.0, 1.0);
+    List<Bucket> buckets =
+        Arrays.asList(Bucket.create(3), Bucket.create(1), Bucket.create(2), Bucket.create(4));
+    thrown.expect(IllegalArgumentException.class);
+    thrown.expectMessage("count should be non-negative.");
+    Distribution.create(6.6, -10, 678.54, bucketBounds, buckets);
+  }
+
+  @Test
+  public void createDistribution_NegativeSumOfSquaredDeviations() {
+    List<Double> bucketBounds = Arrays.asList(-1.0, 0.0, 1.0);
+    List<Bucket> buckets =
+        Arrays.asList(Bucket.create(0), Bucket.create(0), Bucket.create(0), Bucket.create(0));
+    thrown.expect(IllegalArgumentException.class);
+    thrown.expectMessage("sum of squared deviations should be non-negative.");
+    Distribution.create(6.6, 0, -678.54, bucketBounds, buckets);
+  }
+
+  @Test
+  public void createDistribution_ZeroCountAndPositiveMean() {
+    List<Double> bucketBounds = Arrays.asList(-1.0, 0.0, 1.0);
+    List<Bucket> buckets =
+        Arrays.asList(Bucket.create(0), Bucket.create(0), Bucket.create(0), Bucket.create(0));
+    thrown.expect(IllegalArgumentException.class);
+    thrown.expectMessage("mean should be 0 if count is 0.");
+    Distribution.create(6.6, 0, 0, bucketBounds, buckets);
+  }
+
+  @Test
+  public void createDistribution_ZeroCountAndSumOfSquaredDeviations() {
+    List<Double> bucketBounds = Arrays.asList(-1.0, 0.0, 1.0);
+    List<Bucket> buckets =
+        Arrays.asList(Bucket.create(0), Bucket.create(0), Bucket.create(0), Bucket.create(0));
+    thrown.expect(IllegalArgumentException.class);
+    thrown.expectMessage("sum of squared deviations should be 0 if count is 0.");
+    Distribution.create(0, 0, 678.54, bucketBounds, buckets);
+  }
+
+  @Test
+  public void createDistribution_NullBucketBounds() {
+    List<Bucket> buckets =
+        Arrays.asList(Bucket.create(3), Bucket.create(1), Bucket.create(2), Bucket.create(4));
+    thrown.expect(NullPointerException.class);
+    thrown.expectMessage("bucketBoundaries list should not be null.");
+    Distribution.create(6.6, 10, 678.54, null, buckets);
+  }
+
+  @Test
+  public void createDistribution_UnorderedBucketBounds() {
+    List<Double> bucketBounds = Arrays.asList(0.0, -1.0, 1.0);
+    List<Bucket> buckets =
+        Arrays.asList(Bucket.create(3), Bucket.create(1), Bucket.create(2), Bucket.create(4));
+    thrown.expect(IllegalArgumentException.class);
+    thrown.expectMessage("bucket boundaries not sorted.");
+    Distribution.create(6.6, 10, 678.54, bucketBounds, buckets);
+  }
+
+  @Test
+  public void createDistribution_NullBucketList() {
+    List<Double> bucketBounds = Arrays.asList(-1.0, 0.0, 1.0);
+    thrown.expect(NullPointerException.class);
+    thrown.expectMessage("bucket list should not be null.");
+    Distribution.create(6.6, 10, 678.54, bucketBounds, null);
+  }
+
+  @Test
+  public void createDistribution_NullBucket() {
+    List<Double> bucketBounds = Arrays.asList(-1.0, 0.0, 1.0);
+    List<Bucket> buckets =
+        Arrays.asList(Bucket.create(3), Bucket.create(1), null, Bucket.create(4));
+    thrown.expect(NullPointerException.class);
+    thrown.expectMessage("bucket should not be null.");
+    Distribution.create(6.6, 10, 678.54, bucketBounds, buckets);
+  }
+
+  @Test
+  public void testEquals() {
+    new EqualsTester()
+        .addEqualityGroup(
+            Distribution.create(
+                10,
+                10,
+                1,
+                Arrays.asList(-5.0, 0.0, 5.0),
+                Arrays.asList(
+                    Bucket.create(3), Bucket.create(1), Bucket.create(2), Bucket.create(4))),
+            Distribution.create(
+                10,
+                10,
+                1,
+                Arrays.asList(-5.0, 0.0, 5.0),
+                Arrays.asList(
+                    Bucket.create(3), Bucket.create(1), Bucket.create(2), Bucket.create(4))))
+        .addEqualityGroup(
+            Distribution.create(
+                -7,
+                10,
+                23.456,
+                Arrays.asList(-5.0, 0.0, 5.0),
+                Arrays.asList(
+                    Bucket.create(3), Bucket.create(1), Bucket.create(2), Bucket.create(4))))
+        .testEquals();
+  }
+}