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 org.apache.calcite.linq4j;
  import org.junit.jupiter.api.Test;
  
  import java.util.ArrayList;
  import java.util.List;
  import java.util.stream.Collectors;
  import java.util.stream.IntStream;
  
  import static org.hamcrest.CoreMatchers.is;
  import static org.hamcrest.CoreMatchers.nullValue;
  import static org.hamcrest.MatcherAssert.assertThat;
  import static org.hamcrest.Matchers.hasSize;
  import static org.hamcrest.Matchers.hasToString;
  
  /** Tests for {@link org.apache.calcite.linq4j.MemoryEnumerable}. */
  class MemoryEnumerableTest {
  
    @Test void testHistoryAndFuture() {
      final Enumerable<Integer> input =
          Linq4j.asEnumerable(IntStream.range(0, 100)
              .boxed().collect(Collectors.toList()));
  
      final MemoryEnumerable<Integer> integers = new MemoryEnumerable<>(input, 5, 1);
      final Enumerator<MemoryFactory.Memory<Integer>> enumerator = integers.enumerator();
  
      final List<MemoryFactory.Memory<Integer>> results = new ArrayList<>();
      while (enumerator.moveNext()) {
        final MemoryFactory.Memory<Integer> current = enumerator.current();
        results.add(current);
      }
  
      assertThat(results, hasSize(100));
      // First entry
      assertThat((int) results.get(0).get(), is(0));
      assertThat((int) results.get(0).get(1), is(1));
      assertThat(results.get(0).get(-2), nullValue());
      // Last entry
      assertThat((int) results.get(99).get(), is(99));
      assertThat((int) results.get(99).get(-2), is(97));
      assertThat(results.get(99).get(1), nullValue());
    }
  
    @Test void testModularInteger() {
      final ModularInteger modularInteger = new ModularInteger(4, 5);
      assertThat(modularInteger, hasToString("4 mod 5"));
  
      final ModularInteger plus = modularInteger.plus(1);
      assertThat(plus, hasToString("0 mod 5"));
  
      final ModularInteger minus = modularInteger.plus(-6);
      assertThat(minus, hasToString("3 mod 5"));
    }
  }
  