com.github.robtimus.junit.support.collections.EnumerationTests Maven / Gradle / Ivy
/*
* EnumerationTests.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 static org.junit.jupiter.api.Assertions.assertTrue;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Enumeration;
import java.util.List;
import java.util.NoSuchElementException;
import org.junit.jupiter.api.BeforeEach;
import org.junit.jupiter.api.DisplayName;
import org.junit.jupiter.api.Test;
/**
* Base interface for testing separate {@link Enumeration} functionalities.
*
* @author Rob Spoor
* @param The element type of the enumeration to test.
*/
public interface EnumerationTests {
/**
* Returns the enumeration to test.
*
* This method will be called only once for each test. This makes it possible to initialize the enumeration in a method annotated with
* {@link BeforeEach}, and perform additional tests after the pre-defined test has finished.
*
* @return The enumeration to test.
*/
Enumeration enumeration();
/**
* Returns the expected elements returned by the enumeration to test.
*
* @return The expected elements returned by the enumeration to test.
*/
Collection expectedElements();
/**
* Returns whether or not the enumeration to test has a fixed order.
*
* @return {@code true} if the enumeration to test has a fixed order, or {@code false} if the order is unspecified.
*/
boolean fixedOrder();
/**
* Contains tests for {@link Enumeration#hasMoreElements()} and {@link Enumeration#nextElement()}.
*
* @author Rob Spoor
* @param The element type of the enumeration to test.
*/
@DisplayName("iteration")
interface IterationTests extends EnumerationTests {
/**
* Tests iteration using {@link Enumeration#hasMoreElements()} and {@link Enumeration#nextElement()}.
*/
@Test
@DisplayName("iteration")
default void testIteration() {
Enumeration enumeration = enumeration();
Collection expectedElements = expectedElements();
List elements = new ArrayList<>(expectedElements.size());
while (enumeration.hasMoreElements()) {
// call enumeration.hasMoreelements() again to make sure it doesn't have any unexpected side effects
assertTrue(enumeration.hasMoreElements());
T element = enumeration.nextElement();
elements.add(element);
}
assertThrows(NoSuchElementException.class, enumeration::nextElement);
assertHasElements(elements, expectedElements, fixedOrder());
}
/**
* Tests calling {@link Enumeration#nextElement()} without {@link Enumeration#hasMoreElements()}.
* It calls {@link Enumeration#nextElement()} once for each element in {@link #expectedElements()}.
*/
@Test
@DisplayName("nextElement() without hasMoreElements()")
default void testNextElementWithoutHasMoreElements() {
Enumeration enumeration = enumeration();
Collection expectedElements = expectedElements();
List elements = new ArrayList<>(expectedElements.size());
for (int i = 0; i < expectedElements.size(); i++) {
T element = enumeration.nextElement();
elements.add(element);
}
assertThrows(NoSuchElementException.class, enumeration::nextElement);
assertHasElements(elements, expectedElements, fixedOrder());
}
}
}