@Test
public void test_flatMap_null_right() {
// prepare
final String left = "foo";
Pair<String> pair = new Pair<>(left, null);
// action
Pair<Integer> result =
pair.flatMap(
(l, r) -> {
final int lengthL = (l == null ? 0 : l.length());
final int lengthR = (r == null ? 0 : r.length());
Pair<Integer> tmp = new Pair<>(lengthL, lengthR);
reverse(tmp);
return tmp;
});
// check
assertEquals(left.length(), result.getRight().intValue());
assertEquals(0, result.getLeft().intValue());
}
private <T> void reverse(Pair<T> pair) {
final T left = pair.getLeft();
pair.setLeft(pair.getRight());
pair.setRight(left);
}