Assert equals between 2 Lists in Junit

Kamal picture Kamal · Jul 13, 2010 · Viewed 221.8k times · Source

How can I make an equality assertion between lists in a JUnit test case? Equality should be between the content of the list.

For example:

List<String> numbers = Arrays.asList("one", "two", "three");
List<String> numbers2 = Arrays.asList("one", "two", "three");
List<String> numbers3 = Arrays.asList("one", "two", "four"); 

// numbers should be equal to numbers2
//numbers should not be equal to numbers3

Answer

djeikyb picture djeikyb · May 19, 2012

For junit4! This question deserves a new answer written for junit5.

I realise this answer is written a couple years after the question, probably this feature wasn't around then. But now, it's easy to just do this:

@Test
public void test_array_pass()
{
  List<String> actual = Arrays.asList("fee", "fi", "foe");
  List<String> expected = Arrays.asList("fee", "fi", "foe");

  assertThat(actual, is(expected));
  assertThat(actual, is(not(expected)));
}

If you have a recent version of Junit installed with hamcrest, just add these imports:

import static org.junit.Assert.*;
import static org.hamcrest.CoreMatchers.*;

http://junit.org/junit4/javadoc/latest/org/junit/Assert.html#assertThat(T, org.hamcrest.Matcher)

http://junit.org/junit4/javadoc/latest/org/hamcrest/CoreMatchers.html

http://junit.org/junit4/javadoc/latest/org/hamcrest/core/Is.html