1 files changed, 47 insertions, 0 deletions
diff --git a/impl_core/src/test/java/io/opencensus/implcore/internal/UtilsTest.java b/impl_core/src/test/java/io/opencensus/implcore/internal/UtilsTest.java
new file mode 100644
index 00000000..2e0bde21
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+++ b/impl_core/src/test/java/io/opencensus/implcore/internal/UtilsTest.java
@@ -0,0 +1,47 @@
+/*
+ * 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.internal;
+
+import java.util.Arrays;
+import java.util.List;
+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 Utils}. */
+@RunWith(JUnit4.class)
+public class UtilsTest {
+  @Rule public ExpectedException thrown = ExpectedException.none();
+
+  @Test
+  public void checkListElementNull() {
+    List<Double> list = Arrays.asList(0.0, 1.0, 2.0, null);
+    thrown.expect(NullPointerException.class);
+    thrown.expectMessage("null");
+    Utils.checkListElementNotNull(list, null);
+  }
+
+  @Test
+  public void checkListElementNull_WithMessage() {
+    List<Double> list = Arrays.asList(0.0, 1.0, 2.0, null);
+    thrown.expect(NullPointerException.class);
+    thrown.expectMessage("list should not be null.");
+    Utils.checkListElementNotNull(list, "list should not be null.");
+  }
+}