com.github.robtimus.junit.support.collections.IterableTests Maven / Gradle / Ivy
/*
* IterableTests.java
* Copyright 2020 Rob Spoor
*
* 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 com.github.robtimus.junit.support.collections;
import static com.github.robtimus.junit.support.collections.CollectionAssertions.assertHasElements;
import static org.junit.jupiter.api.Assertions.assertThrows;
import java.util.ArrayList;
import java.util.Collection;
import java.util.HashSet;
import java.util.List;
import java.util.function.Consumer;
import org.junit.jupiter.api.BeforeEach;
import org.junit.jupiter.api.DisplayName;
import org.junit.jupiter.api.Test;
/**
* Base interface for testing separate {@link Iterable} functionalities.
*
* @author Rob Spoor
* @param The element type of the iterable to test.
*/
public interface IterableTests {
/**
* Returns the iterable to test. This should be populated, i.e. not empty, unless the iterable can only be empty.
*
* This method will be called only once for each test. This makes it possible to initialize the iterable in a method annotated with
* {@link BeforeEach}, and perform additional tests after the pre-defined test has finished.
*
* @return The iterable to test.
*/
Iterable iterable();
/**
* Returns the expected elements contained by the iterable to test.
* This should not be of the same type as the iterable to test, but preferably of some well-known iterable type like {@link ArrayList} or
* {@link HashSet}.
*
* @return The expected elements contained by the iterable to test.
*/
Collection expectedElements();
/**
* Returns whether or not the iterable to test has a fixed order.
*
* @return {@code true} if the iterable to test has a fixed order, or {@code false} if the order is unspecified.
*/
boolean fixedOrder();
/**
* Contains tests for {@link Iterable#forEach(Consumer)}.
*
* @author Rob Spoor
* @param The element type of the iterable to test.
*/
@DisplayName("forEach(Consumer)")
interface ForEachTests extends IterableTests {
@Test
@DisplayName("forEach(Consumer)")
default void testForEach() {
Iterable iterable = iterable();
List elements = new ArrayList<>();
iterable.forEach(elements::add);
assertHasElements(elements, expectedElements(), fixedOrder());
}
@Test
@DisplayName("forEach(Consumer) with null consumer")
default void testForEachWithNullConsumer() {
Iterable iterable = iterable();
assertThrows(NullPointerException.class, () -> iterable.forEach(null));
}
}
}