Have you ever written an equals method, along with five screens of unit tests to test it? Or worse: not bothered to test it at all, because “the IDE generates it anyway”?
EqualsVerifier helps you. Testing equals can be as simple as:
@Test
public void equalsContract() {
EqualsVerifier.forClass(Foo.class).verify();
}If you feel EqualsVerifier is too strict, you can make it more lenient:
@Test
public void simpleEqualsContract() {
EqualsVerifier.simple().forClass(Foo.class).verify();
}And EqualsVerifier even gives you 100% coverage on equals and hashCode methods.
Don’t forget to add it to your build!
<dependency>
<groupId>nl.jqno.equalsverifier</groupId>
<artifactId>equalsverifier</artifactId>
<version>3.8.2</version>
<scope>test</scope>
</dependency>