Class Iterables

src/main/java/org/assertj/core/internal/Iterables.java:73–979

Reusable assertions for Iterable s. @author Alex Ruiz @author Yvonne Wang @author Maciej Jaskowski @author Nicolas François @author Joel Costigliola

 * @author Joel Costigliola
 */
public class Iterables {

  private static final Iterables INSTANCE = new Iterables();
  private final ComparisonStrategy comparisonStrategy;
  @VisibleForTesting
  Failures failures = Failures.instance();
  @VisibleForTesting
  Conditions conditions = Conditions.instance();

  /**
   * Returns the singleton instance of this class based on {@link StandardComparisonStrategy}.
   * 
   * @return the singleton instance of this class based on {@link StandardComparisonStrategy}.
   */
  public static Iterables instance() {
    return INSTANCE;
  }

  @VisibleForTesting
  Iterables() {
    this(StandardComparisonStrategy.instance());
  }

  public Iterables(ComparisonStrategy comparisonStrategy) {
    this.comparisonStrategy = comparisonStrategy;
  }

  @VisibleForTesting
  public Comparator<?> getComparator() {
    if (comparisonStrategy instanceof ComparatorBasedComparisonStrategy) {
      return ((ComparatorBasedComparisonStrategy) comparisonStrategy).getComparator();
    }
    return null;
  }

  /**
   * Asserts that the given <code>{@link Iterable}</code> is {@code null} or empty.
   * 
   * @param info contains information about the assertion.
   * @param actual the given {@code Iterable}.
   * @throws AssertionError if the given {@code Iterable} is not {@code null} *and* contains one or more elements.
   */
  public void assertNullOrEmpty(AssertionInfo info, Iterable<?> actual) {
    if (actual == null || isNullOrEmpty(actual)) {
      return;
    }
    throw failures.failure(info, shouldBeNullOrEmpty(actual));
  }

  /**
   * Asserts that the given {@code Iterable} is empty.
   * 
   * @param info contains information about the assertion.
   * @param actual the given {@code Iterable}.
   * @throws AssertionError if the given {@code Iterable} is {@code null}.
   * @throws AssertionError if the given {@code Iterable} is not empty.
   */
  public void assertEmpty(AssertionInfo info, Iterable<?> actual) {