public void testAllEqual() {
Ordering<Object> comparator = Ordering.allEqual();
assertSame(comparator, comparator.reverse());
assertEquals(comparator.compare(null, null), 0);
assertEquals(comparator.compare(new Object(), new Object()), 0);
assertEquals(comparator.compare("apples", "oranges"), 0);
assertSame(comparator, reserialize(comparator));
assertEquals("Ordering.allEqual()", comparator.toString());
List<String> strings = ImmutableList.of("b", "a", "d", "c");
assertEquals(strings, comparator.sortedCopy(strings));
assertEquals(strings, comparator.immutableSortedCopy(strings));
}
// A more limited test than the one that follows, but this one uses the
// actual public API.
public void testArbitrary_withoutCollisions() {
List<Object> list = Lists.newArrayList();
for (int i = 0; i < 50; i++) {
list.add(new Object());
}
Ordering<Object> arbitrary = Ordering.arbitrary();
Collections.sort(list, arbitrary);
// Now we don't care what order it's put the list in, only that
// comparing any pair of elements gives the answer we expect.
Helpers.testComparator(arbitrary, list);
assertEquals("Ordering.arbitrary()", arbitrary.toString());
}
public void testNatural() {
Ordering<Integer> comparator = Ordering.natural();
Helpers.testComparator(comparator, Integer.MIN_VALUE, -1, 0, 1, Integer.MAX_VALUE);
try {
comparator.compare(1, null);
fail();
} catch (NullPointerException expected) {
}
try {
comparator.compare(null, 2);
fail();
} catch (NullPointerException expected) {
}
try {
comparator.compare(null, null);
fail();
} catch (NullPointerException expected) {
}
assertSame(comparator, reserialize(comparator));
assertEquals("Ordering.natural()", comparator.toString());
}
public void testUsingToString() {
Ordering<Object> ordering = Ordering.usingToString();
Helpers.testComparator(ordering, 1, 12, 124, 2);
assertEquals("Ordering.usingToString()", ordering.toString());
assertSame(ordering, reserialize(ordering));
}