@Test
    void testHealthCheckService() throws Exception {
        final WebClient client = WebClient.of(newUrl("h1c"));

        HttpResponse response = client.get("/internal/healthcheck");
        AggregatedHttpResponse res = response.aggregate().get();
        assertThat(res.status()).isEqualTo(HttpStatus.OK);

        response = client.post("/internal/healthcheck", "{\"healthy\":false}");
        res = response.aggregate().get();
        assertThat(res.status()).isEqualTo(HttpStatus.SERVICE_UNAVAILABLE);
    }
This uses {@link ArmeriaAutoConfiguration} for integration tests.
application-autoConfTest.yml will be loaded with minimal settings to make it work.
spring/boot3-autoconfigure/src/test/java/com/linecorp/armeria/spring/ArmeriaAutoConfigurationTest.java