When using WebFlux, server.error.include-binding-errors=ALWAYS no longer has an effect when the BindingResult exception is the cause of a ResponseStatusException #41984
Description
Background
Since Boot 2.3 binding errors are no longer included in the default error page by default.
The resolution, until this commit, was to set this property accordingly.
server.error.include-binding-errors=ALWAYS
Unfortunately this no longer works in Boot 3.2.6+.
Expected Behaviour/Repro
Full repro here
Code
@SpringBootApplication public class DemoApplication { public static void main(String[] args) { System.setProperty("server.error.include-message", "ALWAYS"); System.setProperty("server.error.include-binding-errors", "ALWAYS"); SpringApplication.run(DemoApplication.class, args); } @RestController public static class Controller { @GetMapping("/manualBindError") public Mono<ResponseEntity<String>> repro() { BindException bindException = new BindException(new RuntimeException("error"), "oh oh"); ObjectError objectError = new ObjectError("oh oh", new String[] {"CODE"}, null, "MESSAGE"); bindException.addError(objectError); throw new ResponseStatusException(400, "a reason", bindException); } } }When we hit http://localhost:8080/manualBindError
Expected
Something resembling the below - with errors intact.
{ "timestamp": "2024-08-21T13:20:39.377+00:00", "path": "/manualBindError", "status": 400, "error": "Bad Request", "message": "a reason", "requestId": "d4b54677-3", "errors": [ { "codes": [ "CODE" ], "arguments": null, "defaultMessage": "MESSAGE", "objectName": "oh oh", "code": "CODE" } ] }Actual
Errors are missing.
{ "timestamp": "2024-08-21T13:27:27.504+00:00", "path": "/manualBindError", "status": 400, "error": "Bad Request", "requestId": "ae84da6d-1", "message": "a reason" }Root Cause
The code below was removed from DefaultErrorAttributes.
private Throwable determineException(Throwable error) { if (error instanceof ResponseStatusException) { return (error.getCause() != null) ? error.getCause() : error; } return error; }This is problematic if the cause was an instance of BindingResult as this is no longer true, so the errors aren't added regardless of property value....
private void handleException(Map<String, Object> errorAttributes, Throwable error, MergedAnnotation<ResponseStatus> responseStatusAnnotation, boolean includeStackTrace) { Throwable exception; if (error instanceof BindingResult bindingResult) { errorAttributes.put("message", error.getMessage()); errorAttributes.put("errors", bindingResult.getAllErrors()); exception = error; }Resolution?
I can fix this by exposing a custom ErrorAttributes Bean in each app. However, is this the intention or is this a bug? If it's the former then a documentation update would be handy as this is a breaking change.