1 files changed, 115 insertions, 0 deletions
diff --git a/impl_core/src/test/java/io/opencensus/implcore/metrics/export/MetricProducerManagerImplTest.java b/impl_core/src/test/java/io/opencensus/implcore/metrics/export/MetricProducerManagerImplTest.java
new file mode 100644
index 00000000..e549dadb
--- /dev/null
+++ b/impl_core/src/test/java/io/opencensus/implcore/metrics/export/MetricProducerManagerImplTest.java
@@ -0,0 +1,115 @@
+/*
+ * 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.implcore.metrics.export;
+
+import static com.google.common.truth.Truth.assertThat;
+
+import io.opencensus.metrics.export.MetricProducer;
+import io.opencensus.metrics.export.MetricProducerManager;
+import java.util.Set;
+import org.junit.Before;
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.rules.ExpectedException;
+import org.junit.runner.RunWith;
+import org.junit.runners.JUnit4;
+import org.mockito.Mock;
+import org.mockito.MockitoAnnotations;
+
+/** Unit tests for {@link MetricProducerManagerImpl}. */
+@RunWith(JUnit4.class)
+public class MetricProducerManagerImplTest {
+
+  private final MetricProducerManager metricProducerManager = new MetricProducerManagerImpl();
+  @Mock private MetricProducer metricProducer;
+  @Mock private MetricProducer metricProducerOther;
+
+  @Rule public final ExpectedException thrown = ExpectedException.none();
+
+  @Before
+  public void setUp() {
+    MockitoAnnotations.initMocks(this);
+  }
+
+  @Test
+  public void add_DisallowsNull() {
+    thrown.expect(NullPointerException.class);
+    metricProducerManager.add(null);
+  }
+
+  @Test
+  public void add() {
+    metricProducerManager.add(metricProducer);
+    assertThat(metricProducerManager.getAllMetricProducer()).containsExactly(metricProducer);
+  }
+
+  @Test
+  public void add_DuplicateElement() {
+    metricProducerManager.add(metricProducer);
+    Set<MetricProducer> metricProducerSet = metricProducerManager.getAllMetricProducer();
+    assertThat(metricProducerSet).containsExactly(metricProducer);
+    metricProducerManager.add(metricProducer);
+    // Returns the same object.
+    assertThat(metricProducerManager.getAllMetricProducer()).isSameAs(metricProducerSet);
+  }
+
+  @Test
+  public void add_MultipleElements() {
+    metricProducerManager.add(metricProducer);
+    Set<MetricProducer> metricProducerSet = metricProducerManager.getAllMetricProducer();
+    assertThat(metricProducerSet).containsExactly(metricProducer);
+    metricProducerManager.add(metricProducerOther);
+    // Returns the same object.
+    assertThat(metricProducerManager.getAllMetricProducer())
+        .containsExactly(metricProducer, metricProducerOther);
+  }
+
+  @Test
+  public void addAndRemove() {
+    metricProducerManager.add(metricProducer);
+    assertThat(metricProducerManager.getAllMetricProducer()).containsExactly(metricProducer);
+    metricProducerManager.remove(metricProducer);
+    assertThat(metricProducerManager.getAllMetricProducer()).isEmpty();
+  }
+
+  @Test
+  public void remove_DisallowsNull() {
+    thrown.expect(NullPointerException.class);
+    metricProducerManager.remove(null);
+  }
+
+  @Test
+  public void remove_FromEmpty() {
+    metricProducerManager.remove(metricProducer);
+    assertThat(metricProducerManager.getAllMetricProducer()).isEmpty();
+  }
+
+  @Test
+  public void remove_NotPresent() {
+    metricProducerManager.add(metricProducer);
+    Set<MetricProducer> metricProducerSet = metricProducerManager.getAllMetricProducer();
+    assertThat(metricProducerSet).containsExactly(metricProducer);
+    metricProducerManager.remove(metricProducerOther);
+    // Returns the same object.
+    assertThat(metricProducerManager.getAllMetricProducer()).isSameAs(metricProducerSet);
+  }
+
+  @Test
+  public void getAllMetricProducer_empty() {
+    assertThat(metricProducerManager.getAllMetricProducer()).isEmpty();
+  }
+}