DynamicContainers.java

public class TestAcceptedMediaTypes {

	private static final MediaType[] SUPPORTED_MEDIA_TYPES = new MediaType[] { MediaType.APPLICATION_JSON_UTF8,
			MediaType.APPLICATION_JSON, MediaType.APPLICATION_XML };

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

		...
		List<DynamicContainer> dynamicContainers = 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)) {
					List<DynamicTest> dynamicTests = new ArrayList<>();
					for (MediaType mediaType : SUPPORTED_MEDIA_TYPES) {
						dynamicTests.add(dynamicTest(mediaType.toString(),
								() -> mockMvc.perform(post(builder.toString()).contentType(mediaType))
										.andExpect(status().is(IsNot.not(415)))));
					}
					dynamicContainers.add(dynamicContainer(builder.toString(), dynamicTests));
				}
			}
		}
		return dynamicContainers;
	}
}