Does Hamcrest contain test runner or should I use a runner from another framework?

Question

I've found only Hamcrest assertions in Hamcrest project.

Tests in the applications I saw are run with JUnit runner.

Is there a way to run tests with Hamcrest or is Hamcrest not for this?

Answer 1

Hamcrest is not a testing framework, it is an assertions library which tries to make tests more readable.

JUnit 4 (and Hamcrest itself) provides an assertThat() method which accepts a Hamcrest matcher, for example:

import static org.hamcrest.Matchers.is;
import static org.junit.Assert.assertThat;

import org.junit.Test;

public class ATest {
    @Test
    public void someTest() {
        String expected = "...";

        String actual = doSomething();

        assertThat(actual, is(expected));

    }
}

So, a typical usage pattern is:

• Run your tests with a JUnit runner
• Use Hamcrest's matchers to assert the success (or otherwise) of your tests

More details on Hamcrest here and on its use alongside JUnit here.