PreconditionsTest.java

package org.needle4j.common;

import static org.needle4j.common.Preconditions.checkState;

import org.junit.Rule;
import org.junit.Test;
import org.junit.rules.ExpectedException;

public class PreconditionsTest {

    @Rule
    public final ExpectedException thrown = ExpectedException.none();

    @Test
    public void shouldThrowIllegalStateException() {
        thrown.expect(IllegalStateException.class);
        thrown.expectMessage("failed with param=foo");

        checkState(false, "failed with param=%s", "foo");
    }

    @Test
    public void shouldPassWithoutException() {
        checkState(true, "should pass");
        // success if no exception thrown
    }

}