Wiremock property injection for SpringBootTests

ExampleTest.java

@SpringBootTest
@WithWiremock(injectHostInto = "your.application.property.serviceUrl")
public class ExampleTest {
    @Autowired
    private WiremockServcer wiremock;
    @Value("${your.application.property.serviceUrl}")
    private String serviceUrl;
    
    @Test
    void testWiremock() {
        wiremock.stubFor(...):
        WebClient.create(serviceUrl).post()....
        wiremock.verify(...);
    }
}

WiremockInitializer.java

import java.util.Map;

import org.springframework.boot.test.util.TestPropertyValues;
import org.springframework.context.ApplicationContextInitializer;
import org.springframework.context.ConfigurableApplicationContext;
import org.springframework.context.event.ContextClosedEvent;
import org.springframework.test.context.event.AfterTestExecutionEvent;

import com.github.tomakehurst.wiremock.WireMockServer;
import com.github.tomakehurst.wiremock.core.WireMockConfiguration;
import com.google.common.base.Preconditions;

class WiremockInitializer implements ApplicationContextInitializer<ConfigurableApplicationContext> {

    private static final String INJECT_PROPERTY = "wiremock.injectHostInto";

    @Override
    public void initialize(ConfigurableApplicationContext configurableApplicationContext) {
        final WireMockServer wiremockServer = startWiremock();
        injectWiremockHostIntoProperty(configurableApplicationContext, wiremockServer);
        registerWiremockServerAsBean(configurableApplicationContext, wiremockServer);
        addLifecycleEvents(configurableApplicationContext, wiremockServer);
    }

    private WireMockServer startWiremock() {
        final WireMockServer wiremockServer = new WireMockServer(new WireMockConfiguration()
                .dynamicPort());
        wiremockServer.start();
        return wiremockServer;
    }

    private void injectWiremockHostIntoProperty(ConfigurableApplicationContext applicationContext,
            WireMockServer wiremockServer) {
        final String injectPropertyName = applicationContext.getEnvironment()
                .getProperty(INJECT_PROPERTY);
        Preconditions.checkState(injectPropertyName != null,
                "You need to define the property '%s' to hold the name of the "
                        + "property into which the wiremock host will be injected",
                INJECT_PROPERTY);
        TestPropertyValues
                .of(Map.of(injectPropertyName, wiremockServer.baseUrl()))
                .applyTo(applicationContext);
    }

    private void registerWiremockServerAsBean(ConfigurableApplicationContext applicationContext,
            WireMockServer wiremockServer) {
        applicationContext
                .getBeanFactory()
                .registerSingleton("wiremockServer", wiremockServer);
    }

    private void addLifecycleEvents(ConfigurableApplicationContext applicationContext,
            WireMockServer wiremockServer) {
        applicationContext.addApplicationListener(applicationEvent -> {
            if (applicationEvent instanceof AfterTestExecutionEvent) {
                wiremockServer.resetAll();
            }
            if (applicationEvent instanceof ContextClosedEvent) {
                wiremockServer.stop();
            }
        });
    }
}

WithWiremock.java

import static java.lang.annotation.ElementType.TYPE;
import static java.lang.annotation.RetentionPolicy.RUNTIME;

import java.lang.annotation.Retention;
import java.lang.annotation.Target;

import org.springframework.boot.test.autoconfigure.properties.PropertyMapping;
import org.springframework.test.context.ContextConfiguration;

@Retention(RUNTIME)
@Target(TYPE)
@ContextConfiguration(initializers = WiremockInitializer.class)
@PropertyMapping("wiremock")
public @interface WithWiremock {
    @PropertyMapping("injectHostInto")
    String injectHostInto() default "";
}