// ensures that the number of invocations looks sane
    void assertInvariants(int expectedBytes) {
      // we should have seen as many bytes as the next multiple of chunk after expectedBytes - 1
      assertEquals(out.toByteArray().length, ceilToMultiple(expectedBytes, chunkSize));
      assertEquals(expectedBytes / chunkSize, processCalled);
      assertEquals(expectedBytes % chunkSize != 0, remainingCalled);
    }

    // ensures that the number of invocations looks sane
    void assertInvariants(int expectedBytes) {
      // we should have seen as many bytes as the next multiple of chunk after expectedBytes - 1
      assertEquals(out.toByteArray().length, ceilToMultiple(expectedBytes, chunkSize));
      assertEquals(expectedBytes / chunkSize, processCalled);
      assertEquals(expectedBytes % chunkSize != 0, remainingCalled);
    }

    verifyNoMoreInteractions(hashFunction, hasher);
  }

  public void testRead_putByteArrayOutOfBound() throws Exception {
    byte[] buf = new byte[100];
    byte[] expectedBytes = buf.clone();
    System.arraycopy(testBytes, 0, expectedBytes, 0, testBytes.length);

    HashingInputStream in = new HashingInputStream(hashFunction, buffer);

    int numOfByteRead = in.read(buf, 0, 100);
    assertEquals(4, numOfByteRead);

    verifyNoMoreInteractions(hashFunction, hasher);
  }

  public void testRead_putByteArrayOutOfBound() throws Exception {
    byte[] buf = new byte[100];
    byte[] expectedBytes = buf.clone();
    System.arraycopy(testBytes, 0, expectedBytes, 0, testBytes.length);

    HashingInputStream in = new HashingInputStream(hashFunction, buffer);

    int numOfByteRead = in.read(buf, 0, 100);
    assertEquals(4, numOfByteRead);