content: /*
   * Copyright 2014-2025 Real Logic Limited.
   *
   * 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
   *
   * https://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.agrona.collections;
  
  import org.junit.jupiter.api.BeforeEach;
  import org.junit.jupiter.api.Test;
  
  import java.util.function.Consumer;
  import java.util.function.IntFunction;
  
  import static org.junit.jupiter.api.Assertions.assertNotNull;
  import static org.junit.jupiter.api.Assertions.assertSame;
  import static org.mockito.Mockito.*;
  
  class IntLruCacheTest
  {
      private static final int CAPACITY = 2;
  
      @SuppressWarnings("unchecked")
      private final IntFunction<AutoCloseable> mockFactory = mock(IntFunction.class);
      @SuppressWarnings("unchecked")
      private final Consumer<AutoCloseable> mockCloser = mock(Consumer.class);
  
      private final IntLruCache<AutoCloseable> cache = new IntLruCache<>(CAPACITY, mockFactory, mockCloser);
  
      private AutoCloseable lastValue;
  
      @BeforeEach
      void setUp()
      {
          when(mockFactory.apply(anyInt())).thenAnswer(
              (inv) ->
              {
                  lastValue = mock(AutoCloseable.class);
                  return lastValue;
              });
      }
  
      @Test
      void shouldUseFactoryToConstructValues()
      {
          final AutoCloseable actual = cache.lookup(1);
  
          assertSame(lastValue, actual);
          assertNotNull(lastValue);
          verifyOneConstructed(1);
      }
  
      @Test
      void shouldCacheValues()
      {
          final AutoCloseable first = cache.lookup(1);
          final AutoCloseable second = cache.lookup(1);
  
          assertSame(lastValue, first);
          assertSame(lastValue, second);
          assertNotNull(lastValue);
          verifyOneConstructed(1);
      }
  
      @Test
      void shouldEvictLeastRecentlyUsedItem()
      {
          final AutoCloseable first = cache.lookup(1);
          cache.lookup(2);
          cache.lookup(3);
  
          verify(mockCloser).accept(first);
      }
  
      @Test
      void shouldReconstructItemsAfterEviction()
      {
          cache.lookup(1);
          final AutoCloseable second = cache.lookup(2);
          cache.lookup(3);
          cache.lookup(1);
  
          verify(mockCloser).accept(second);
          verifyOneConstructed(2);
      }
  
      @Test
      void shouldSupportKeyOfZero()
      {
          final AutoCloseable actual = cache.lookup(0);
  
          assertSame(lastValue, actual);
          assertNotNull(lastValue);
      }
  
      @Test
      void shouldCloseAllOpenResources()
      {
          final AutoCloseable first = cache.lookup(1);
          final AutoCloseable second = cache.lookup(2);
  
          cache.close();
  
          verify(mockCloser).accept(first);
          verify(mockCloser).accept(second);
      }
  
      private void verifyOneConstructed(final int numberOfInvocations)
      {
          verify(mockFactory, times(numberOfInvocations)).apply(1);
      }
  }
  