content: /*
   * Licensed to the Apache Software Foundation (ASF) under one or more
   * contributor license agreements.  See the NOTICE file distributed with
   * this work for additional information regarding copyright ownership.
   * The ASF licenses this file to You 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.alibaba.metrics.common;
  
  import com.alibaba.metrics.Gauge;
  import com.alibaba.metrics.MetricName;
  import org.junit.Assert;
  import org.junit.Test;
  
  import java.util.concurrent.TimeUnit;
  
  public class MetricsCollectorTest {
  
      @Test
      public void testDoNotCollectNullValue() {
          MetricsCollector collector =
                  MetricsCollectorFactory.createNew(TimeUnit.SECONDS.toSeconds(1),
                          1.0 / TimeUnit.MILLISECONDS.toNanos(1), null);
          collector.collect(MetricName.build("TEST"), new Gauge<Object>() {
              @Override
              public Object getValue() {
                  return null;
              }
              @Override
              public long lastUpdateTime() {
                  return 0;
              }
          }, System.currentTimeMillis());
          // null value should not be collected.
          Assert.assertEquals(0, collector.build().size());
      }
  }
  