What is the best way to assert items in an iterable

July 13, 2022

I’ve got the following iterable changes (don’t ask why it’s not in my control). And I want to ensure there are specific items in the changes and I used the following:

Iterable<ChangedValue> changes = record.getValues();

assertEquals(2, Iterables.size(changes));

changes.forEach(entry -> {
    if (entry.getName().equals("Title")) {
        assertEquals("old name", entry.getFrom());
        assertEquals("new name", entry.getTo());
    } else if (entry.getName().equals("Description")) {
        assertEquals("old description", entry.getFrom());
        assertEquals("new description", entry.getTo());
    }
});

The problem with the above is that the above test case passes if the 2nd "change" is something else other than "Description". If changes was a list I would’ve done something like:

assertEquals(2, changes.size());

assertEquals("Title", changes.get(0).getName());
assertEquals("old name", changes.get(0).getFrom());
assertEquals("new name", changes.get(0).getTo());

assertEquals("Description", changes.get(1).getName());
assertEquals("old description", changes.get(1).getFrom());
assertEquals("new description", changes.get(1).getTo());

So my question is, how can I achieve assertions similar to the above with an iterable?

>Solution :

Use an explicit Iterator:

Iterator<ChangedValue> changes = record.getValues().iterator();

assertTrue(changes.hasNext());
ChangedValue change = changes.next();
assertEquals("Title", change.getName());
assertEquals("old name", change.getFrom());
assertEquals("new name", change.getTo());

assertTrue(changes.hasNext());
change = changes.next();
assertEquals("Description", change.getName());
assertEquals("old description", change.getFrom());
assertEquals("new description", change.getTo());

assertFalse(changes.hasNext());