### Question:
WebConfigurer implements ServletContextInitializer, EmbeddedServletContainerCustomizer { @Override public void onStartup(ServletContext servletContext) throws ServletException { if (env.getActiveProfiles().length != 0) { log.info("Web application configuration, using profiles: {}", (Object[]) env.getActiveProfiles()); } EnumSet<DispatcherType> disps = EnumSet.of(DispatcherType.REQUEST, DispatcherType.FORWARD, DispatcherType.ASYNC); initMetrics(servletContext, disps); if (env.acceptsProfiles(JHipsterConstants.SPRING_PROFILE_DEVELOPMENT)) { initH2Console(servletContext); } log.info("Web application fully configured"); } WebConfigurer(Environment env, JHipsterProperties jHipsterProperties); @Override void onStartup(ServletContext servletContext); @Override void customize(ConfigurableEmbeddedServletContainer container); @Bean CorsFilter corsFilter(); @Autowired(required = false) void setMetricRegistry(MetricRegistry metricRegistry);  }### Answer:
@Test public void testStartUpProdServletContext() throws ServletException { env.setActiveProfiles(JHipsterConstants.SPRING_PROFILE_PRODUCTION); webConfigurer.onStartup(servletContext); assertThat(servletContext.getAttribute(InstrumentedFilter.REGISTRY_ATTRIBUTE)).isEqualTo(metricRegistry); assertThat(servletContext.getAttribute(MetricsServlet.METRICS_REGISTRY)).isEqualTo(metricRegistry); verify(servletContext).addFilter(eq("webappMetricsFilter"), any(InstrumentedFilter.class)); verify(servletContext).addServlet(eq("metricsServlet"), any(MetricsServlet.class)); verify(servletContext, never()).addServlet(eq("H2Console"), any(WebServlet.class)); }
@Test public void testStartUpDevServletContext() throws ServletException { env.setActiveProfiles(JHipsterConstants.SPRING_PROFILE_DEVELOPMENT); webConfigurer.onStartup(servletContext); assertThat(servletContext.getAttribute(InstrumentedFilter.REGISTRY_ATTRIBUTE)).isEqualTo(metricRegistry); assertThat(servletContext.getAttribute(MetricsServlet.METRICS_REGISTRY)).isEqualTo(metricRegistry); verify(servletContext).addFilter(eq("webappMetricsFilter"), any(InstrumentedFilter.class)); verify(servletContext).addServlet(eq("metricsServlet"), any(MetricsServlet.class)); verify(servletContext).addServlet(eq("H2Console"), any(WebServlet.class)); }