package org.pojomatic.test;
   
   import org.pojomatic.Pojomatic;
   import org.pojomatic.NoPojomaticPropertiesException;
   
   /**
    * This class is not meant to be a part of the public API.
    */
   public class AssertUtils {
  
    /**
     * Determines if two objects are both null or are equal according to
     * {@link Object#equals(Object)}.
     *
     * @param first the first object to compare
     * @param second the second object to compare
     * @return {@code true} if both objects are null,
     * or {@code first} is non-null and {@code first.equals(second)},
     * {@code false} otherwise
     * @see Object#equals(Object)
     */
    public static boolean equal(Object first, Object second) {
      return first == null ? second == null : first.equals(second);
    }
  
    /**
     * Asserts that two objects are either both null or are equal according to
     * {@link Object#equals(Object)}. If not, an {@code AssertionError} is thrown. If the objects are
     * not equal, but the types of two objects are compatible for equality, then the differences as
     * determined by {@link Pojomatic#diff(Object, Object)} are included in the failure message.
     *
     * @param message the message to add if the assertion fails
     * @param expected will be displayed first if the assertion fails
     * @param actual will be displayed second if the assertion fails
     * @throws AssertionError if the objects are not equal. {@link AssertionError#getMessage()} will
     * include information about the differences
     */
    public static void assertEquals(String message, Object expected, Object actual) {
      if (!equal(expected, actual)) {
        if (expected == null) {
          throw new AssertionError(
            makeBuilder(message).append("expected is null, but actual is ").append(actual));
        }
        if (actual == null) {
          throw new AssertionError(
            makeBuilder(message).append("actual is null, but expected is ").append(expected));
        }
        try {
          if (Pojomatic.areCompatibleForEquals(expected.getClass(), actual.getClass())) {
            throw new AssertionError(appendStandardEqualityMessage(
              makeBuilder(message).append("differences between expected and actual:")
              .append(Pojomatic.diff(expected, actual))
                .append(" ("), expected, actual).append(")").toString());
          }
        }
        catch (NoPojomaticPropertiesException e) {}
        throw new AssertionError(
          appendStandardEqualityMessage(makeBuilder(message), expected, actual).toString());
        }
    }
  
    private static StringBuilder appendStandardEqualityMessage(
      StringBuilder builder, Object expected, Object actual) {
      return builder
        .append("expected:<").append(expected).append("> but was:<").append(actual).append(">");
    }
  
    private static StringBuilder makeBuilder(String message) {
      return message == null ? new StringBuilder() : new StringBuilder(message).append(" ");
    }
  
    private AssertUtils() {}
  
  }