I have previously blogged about Hamcrest, and using its assertThat methods in preference to JUnit’s Assert.
However, I quickly after discovered FEST Assertions, and happily switched to it. It provides the same improved test readability and improves failure messages as Hamcrest, but has the extra benefit of enabling IDE auto completion, rather than having to search through package and class docs to find the right matcher.
Unfortunately, Fest seems to not longer be actively developed. The last stable release of the 1.x branch, 1.4, was released way back in 2011, and the new 2.x branch never made it to a stable release and hasn’t had a commit since June 2013.
Enter AssertJ…
Assert J
AssertJ is a fork of Fest Assert, and seems to provide all the benefits plus a bunch of new features.
Collections
For example, it has all the nifty collections handling I so liked from Fest:
List<String> stringList = Lists.newArrayList("A", "B", "C");
assertThat(stringList).contains("A"); //true
assertThat(stringList).doesNotContain("D"); //true
assertThat(stringList).containsOnly("A"); //false
assertThat(stringList).containsExactly("A", "C", "B"); //false
assertThat(stringList).containsExactly("A", "B", "C"); //trueCollect all errors before failing
It also has the ability to catch all failures before failing. For example, the above eample would fail as the first failed assumpion. The below example allows you to see all failed assertions:
List<String> stringList = Lists.newArrayList("A", "B", "C");
SoftAssertions softly = new SoftAssertions();
softly.assertThat(stringList).contains("A"); //true
softly.assertThat(stringList).containsOnly("A"); //false
softly.assertThat(stringList).containsExactly("A", "C", "B"); //false
softly.assertThat(stringList).containsExactly("A", "B", "C"); //true
// Don't forget to call SoftAssertions global verification!
softly.assertAll();And results in a message like this:
The following 2 assertions failed: 1) Expecting: <["A", "B", "C"]> to contain only: <["A"]> elements not found: <[]> and elements not expected: <["B", "C"]>
2) Actual and expected have the same elements but not in the same order, at index 1 actual element was: <"B"> whereas expected element was: <"C">
Definitely worth a look. AssertJ core code and issue tracker are hosted on github.
| Reference: | AssertJ > Fest > Hamcrest from our JCG partner Shaun Abram at the Shaun Abram’s blog blog. |
