DynamicTestFull.java

public class TestAcceptedMediaTypes {

	private static final MediaType[] SUPPORTED_MEDIA_TYPES = new MediaType[] { MediaType.APPLICATION_JSON,
			MediaType.APPLICATION_XML };

	@TestFactory
	Collection<DynamicTest> testAcceptedMediaTypes() throws Exception {

		// Creating a classpath scanner to find all controller classes in project
		ClassPathBeanDefinitionScanner scanner = new ClassPathBeanDefinitionScanner(new DefaultListableBeanFactory(),
				false);
		scanner.addIncludeFilter(new AnnotationTypeFilter(RestController.class));
		Set<BeanDefinition> beanDefinitons = scanner.findCandidateComponents("com.bk.hotel");
		Set<Object> controllers = new HashSet<>();
		Set<Class<?>> controllersClasses = new HashSet<>();

		// Instantiating controller classes
		for (BeanDefinition beanDefiniton : beanDefinitons) {
			String className = beanDefiniton.getBeanClassName();
			Class<?> controllerClazz = ClassLoader.getSystemClassLoader().loadClass(className);
			controllersClasses.add(controllerClazz);

			Constructor<?> constructor = controllerClazz.getDeclaredConstructors()[0];
			Object[] arguments = new Object[constructor.getParameterTypes().length];
			int i = 0;
			for (Class<?> parameterType : constructor.getParameterTypes()) {
				arguments[i] = mock(parameterType);
				i++;
			}
			controllers.add(constructor.newInstance(arguments));
		}

		MockMvc mockMvc = MockMvcBuilders.standaloneSetup(controllers.toArray()).build();
		List<DynamicTest> generatedTests = new ArrayList<>();

		// Check if controller has a POST endpoint and call it with all the different
		// mediatypes, throw an error in a 415 (unsupported media type) is returned
		for (Class<?> controllerClazz : controllersClasses) {
			RequestMapping mapping = controllerClazz.getAnnotationsByType(RequestMapping.class)[0];
			StringBuilder builder = new StringBuilder();
			builder.append(mapping.value()[0]);
			for (Method method : controllerClazz.getMethods()) {
				if (method.isAnnotationPresent(PostMapping.class)) {
					for (MediaType mediaType : SUPPORTED_MEDIA_TYPES) {
						generatedTests.add(dynamicTest(builder.toString() + " " + mediaType,
								() -> mockMvc.perform(post(builder.toString()).accept(mediaType).contentType(mediaType))
										.andExpect(status().is(IsNot.not(415)))));
					}
				}
			}

		}

		return generatedTests;
	}
}