How can I test whether a list is sorted with AssertJ

Question

Given

List<Integer> list = ...

I would like to test with AssertJ whether it is sorted. Something like:

assertThat(list).isSorted()

Is it possible?

score 5 · Accepted Answer · answered Mar 04 '22 at 11:12

5

AssertJ offers out of the box isSorted() and isSortedAccordingTo(Comparator) for list assertions:

List<String> strings = List.of("abc", "DEF");

assertThat(strings).isSorted(); // fails as "abc" is after "DEF" lexicographically
assertThat(strings).isSortedAccordingTo(String.CASE_INSENSITIVE_ORDER); // succeeds

answered Mar 04 '22 at 11:12

Stefano Cordio

1,687
10
20

In case somebody else faces the same issue: I was testing `assertThat(CollectionObject).isSorted()`, which doesn't compile. I should have done something like: `assertThat(ListObject).isSorted()`. – user3429660 Mar 04 '22 at 20:01

score 0 · Answer 2 · answered Mar 04 '22 at 01:00

0

import com.google.common.collect.Ordering;

And

assertTrue(Ordering.natural().isOrdered(list));

answered Mar 04 '22 at 01:00

Landry Toutou

90
4

1

The question is about AssertJ but `assertTrue` probably comes from the testing framework (JUnit / TestNG) – Stefano Cordio Mar 04 '22 at 11:13

How can I test whether a list is sorted with AssertJ

2 Answers2