*
   * @since 19.0
   */
  public static HashFunction concatenating(Iterable<HashFunction> hashFunctions) {
    checkNotNull(hashFunctions);
    // We can't use Iterables.toArray() here because there's no hash->collect dependency
    List<HashFunction> list = new ArrayList<>();
    for (HashFunction hashFunction : hashFunctions) {
      list.add(hashFunction);
    }

import org.jspecify.annotations.NullUnmarked;

/** Tests for AbstractNonStreamingHashFunction. */
@NullUnmarked
public class AbstractNonStreamingHashFunctionTest extends TestCase {
  /**
   * Constructs two trivial HashFunctions (output := input), one streaming and one non-streaming,
   * and checks that their results are identical, no matter which newHasher version we used.
   */
  public void testExhaustive() {
    List<Hasher> hashers =

 *
 * @author Kevin Bourrillion
 * @since 11.0
 */
@Immutable
public interface HashFunction {
  /**
   * Begins a new hash code computation by returning an initialized, stateful {@code Hasher}
   * instance that is ready to receive data. Example:
   *
   * {@snippet :
   * HashFunction hf = Hashing.md5();
   * HashCode hc = hf.newHasher()
   *     .putLong(id)
   *     .putBoolean(isActive)

            fail("Unable to create a random parameter for " + method.getParameterTypes()[i]);
          }
        }
        HashFunction hashFunction1a = (HashFunction) method.invoke(clazz, params1);
        HashFunction hashFunction1b = (HashFunction) method.invoke(clazz, params1);
        HashFunction hashFunction2 = (HashFunction) method.invoke(clazz, params2);

        new EqualsTester()
            .addEqualityGroup(hashFunction1a, hashFunction1b)

    assertHashByteBufferMatchesBytes(hashFunction);
    assertHashByteBufferExhaustsBuffer(hashFunction);
    assertHashByteBufferPreservesByteOrder(hashFunction);
    assertHasherByteBufferPreservesByteOrder(hashFunction);
  }

  static void assertHashByteBufferMatchesBytes(HashFunction hashFunction) {
    Random rng = new Random(0L);

  private Hasher hasher;
  private HashFunction hashFunction;
  private final ByteArrayOutputStream buffer = new ByteArrayOutputStream();

  @SuppressWarnings("DoNotMock")
  @Override
  protected void setUp() throws Exception {
    super.setUp();
    hasher = mock(Hasher.class);
    hashFunction = mock(HashFunction.class);

    when(hashFunction.newHasher()).thenReturn(hasher);
  }

  private Hasher hasher;
  private HashFunction hashFunction;
  private static final byte[] testBytes = new byte[] {'y', 'a', 'm', 's'};
  private ByteArrayInputStream buffer;

  @SuppressWarnings("DoNotMock")
  @Override
  protected void setUp() throws Exception {
    super.setUp();
    hasher = mock(Hasher.class);
    hashFunction = mock(HashFunction.class);
    buffer = new ByteArrayInputStream(testBytes);

  private Hasher hasher;
  private HashFunction hashFunction;
  private static final byte[] testBytes = new byte[] {'y', 'a', 'm', 's'};
  private ByteArrayInputStream buffer;

  @SuppressWarnings("DoNotMock")
  @Override
  protected void setUp() throws Exception {
    super.setUp();
    hasher = mock(Hasher.class);
    hashFunction = mock(HashFunction.class);
    buffer = new ByteArrayInputStream(testBytes);

   * Creates an input stream that hashes using the given {@link HashFunction} and delegates all data
   * read from it to the underlying {@link InputStream}.
   *
   * <p>The {@link InputStream} should not be read from before or after the hand-off.
   */
  public HashingInputStream(HashFunction hashFunction, InputStream in) {
    super(checkNotNull(in));
    this.hasher = checkNotNull(hashFunction.newHasher());
  }

  /**

  // These can probably be removed sooner or later.
  ;

  private final HashFunction hashFunction;

  HashFunctionEnum(HashFunction hashFunction) {
    this.hashFunction = hashFunction;
  }

  HashFunction getHashFunction() {
    return hashFunction;
  }