@Test
public void testEmpty() {
Interleaver<String> interleaver = new Interleaver<>();
assertFalse(interleaver.hasNext());
assertFalse(interleaver.hasPrevious());
interleaver = new Interleaver<>(new ReversibleAdapter<>());
assertFalse(interleaver.hasNext());
assertFalse(interleaver.hasPrevious());
}
@Test(expected = NoSuchElementException.class)
public void testHasPreviousError() {
ReversibleAdapter<String> a = new ReversibleAdapter<>("1", "2", "3");
ReversibleAdapter<String> b = new ReversibleAdapter<>("a");
Interleaver<String> interleaver = new Interleaver<>(a, b);
assertEquals("1", interleaver.next());
assertEquals("a", interleaver.next());
assertEquals("a", interleaver.previous());
assertEquals("1", interleaver.previous());
assertFalse(interleaver.hasPrevious());
interleaver.previous();
}
@Test
public void testInterleaver() {
ReversibleAdapter<String> a = new ReversibleAdapter<>("1", "2", "3");
ReversibleAdapter<String> b = new ReversibleAdapter<>("Z");
ReversibleAdapter<String> c = new ReversibleAdapter<>("a", "b", "c");
Interleaver<String> interleaver = new Interleaver<>(a, b, c);
assertEquals("1", interleaver.next());
assertEquals("Z", interleaver.next());
assertEquals("a", interleaver.next());
assertEquals("2", interleaver.next());
assertEquals("b", interleaver.next());
assertEquals("3", interleaver.next());
assertEquals("c", interleaver.next());
assertFalse(interleaver.hasNext());
assertEquals("c", interleaver.previous());
assertEquals("3", interleaver.previous());
assertEquals("b", interleaver.previous());
assertEquals("2", interleaver.previous());
assertEquals("a", interleaver.previous());
assertEquals("Z", interleaver.previous());
assertEquals("1", interleaver.previous());
assertFalse(interleaver.hasPrevious());
assertEquals("1", interleaver.next());
assertEquals("Z", interleaver.next());
assertEquals("a", interleaver.next());
assertEquals("2", interleaver.next());
assertTrue(interleaver.hasNext());
assertTrue(interleaver.hasPrevious());
assertEquals("2", interleaver.previous());
assertEquals("a", interleaver.previous());
assertEquals("Z", interleaver.previous());
assertEquals("1", interleaver.previous());
assertFalse(interleaver.hasPrevious());
}