Nested Hamcrest Matcher

ServiceExceptionTest.java

@Test
public void shouldCheckWhetherWeHaveAnUsernameAlreadyInUseErrorCode() {
    ServiceException e = new ServiceException("ERR500|532323");
    assertThat(e, hasErrorCode(usernameAlreadyInUse()));
}

TypeSafeMatcher.java

import org.hamcrest.Description;
import org.hamcrest.Factory;
import org.hamcrest.Matcher;
import org.hamcrest.TypeSafeMatcher;

public class ServiceExceptionMatcher extends TypeSafeMatcher<ServiceException> {
    
    private Matcher<?> matcher;

    public ServiceExceptionMatcher(Matcher<?> matcher) {
        this.matcher = matcher;
    }

    @Override
    public void describeTo(Description description) {
        description.appendDescriptionOf(matcher);
    }

    @Override
    public boolean matchesSafely(ServiceException item) {
        return matcher.matches(item);
    }
    
    @Factory
    public static <T> Matcher<ServiceException> hasErrorCode(Matcher<?> matcher) {
      return new ServiceExceptionMatcher(matcher);
    }
    
    public static Matcher<?> usernameAlreadyInUse() {
        return org.hamcrest.Matchers.hasProperty("errorCode", org.hamcrest.core.IsEqual.equalTo("ERR500|532121"));
    }
    
    public static Matcher<?> invalidCredentials() {
        return org.hamcrest.Matchers.hasProperty("errorCode", org.hamcrest.text.IsEqualIgnoringCase.equalToIgnoringCase("ERR500|532126"));
    }
    
    public static Matcher<?> ldapAccessErrorInvalidCredentials() {
        return org.hamcrest.Matchers.hasProperty("errorCode", org.hamcrest.text.IsEqualIgnoringCase.equalToIgnoringCase("ERR500|532343"));
    }
    
    public static Matcher<?> ldapAccessErrorInsufficientCredentials() {
        return org.hamcrest.Matchers.hasProperty("errorCode", org.hamcrest.text.IsEqualIgnoringCase.equalToIgnoringCase("ERR500|532323"));
    }
    
    public static Matcher<?> ldapAccessErrorInvalidUsernameOrPassword() {
        return org.hamcrest.Matchers.hasProperty("errorCode", org.hamcrest.text.IsEqualIgnoringCase.equalToIgnoringCase("ERR500|5321230"));
    }
    
}