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
  // 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 org.apache.cloudstack.utils.linux;
  
  import java.util.Arrays;
  import java.util.List;
  import java.util.Scanner;
  import java.util.stream.Collectors;
  
  import org.junit.After;
  import org.junit.Assert;
  import org.junit.Before;
  import org.junit.Test;
  import org.junit.runner.RunWith;
  import org.mockito.MockedConstruction;
  import org.mockito.Mockito;
  import org.mockito.junit.MockitoJUnitRunner;
  
  @RunWith(MockitoJUnitRunner.class)
  public class MemStatTest {
      final String memInfo = "MemTotal:        5830236 kB\n" +
                             "MemFree:          156752 kB\n" +
                             "Buffers:          326836 kB\n" +
                             "Cached:          2606764 kB\n" +
                             "SwapCached:            0 kB\n" +
                             "Active:          4260808 kB\n" +
                             "Inactive:         949392 kB\n";
  
      MockedConstruction<Scanner> scanner;
  
      @Before
      public void setup() throws Exception {
          scanner = Mockito.mockConstruction(Scanner.class, (mock, context) -> {
              String[] memInfoLines = memInfo.split("\\n");
              List<Boolean> hasNextReturnList = Arrays.stream(memInfoLines).map(line -> true).collect(
                      Collectors.toList());
              hasNextReturnList.add(false);
              Mockito.when(mock.next()).thenReturn(memInfoLines[0], Arrays.copyOfRange(memInfoLines, 1,
                      memInfoLines.length));
              Mockito.when(mock.hasNext()).thenReturn(true,
                      Arrays.copyOfRange(hasNextReturnList.toArray(new Boolean[0]), 1, hasNextReturnList.size()));
          });
  
      }
  
      @After
      public void tearDown() {
          scanner.close();
      }
  
      @Test
      public void getMemInfoParseTest() {
          MemStat memStat = new MemStat();
          if (!System.getProperty("os.name").equals("Linux")) {
              return;
          }
  
          Assert.assertEquals(memStat.getTotal(), 5970161664L);
          Assert.assertEquals(memStat.getAvailable(), 3164520448L);
          Assert.assertEquals(memStat.getFree(), 160514048L);
          Assert.assertEquals(memStat.getCache(), 2669326336L);
      }
  
      @Test
      public void reservedMemoryTest() {
          MemStat memStat = new MemStat(1024, 2048);
          if (!System.getProperty("os.name").equals("Linux")) {
              return;
          }
          Assert.assertEquals(memStat.getTotal(), 5970162688L);
      }
  }
  