Mismatch between documented and actual message code handling for ErrorResponse

[ZeroCyan]

There is a discrepancy between the documentation and the actual implementation regarding the message codes for ErrorResponses.

https://docs.spring.io/spring-framework/reference/web/webmvc/mvc-ann-rest-exceptions.html#mvc-ann-rest-exceptions-i18n describes the following pattern:

The default strategy for message codes follows the pattern: problemDetail.[type|title|detail].[fully qualified exception class name]

As you can see in the following references, detail is not used when searching for the message code. This does happen for problemDetail.title and problemDetail.type

spring-framework/spring-web/src/main/java/org/springframework/web/ErrorResponse.java

Line 162 in 0435e9c

return "problemDetail.type." + exceptionType.getName();

spring-framework/spring-web/src/main/java/org/springframework/web/ErrorResponse.java

Line 172 in 0435e9c

return "problemDetail.title." + exceptionType.getName();

spring-framework/spring-web/src/main/java/org/springframework/web/ErrorResponse.java

Line 184 in 0435e9c

return "problemDetail." + exceptionType.getName() + (suffix != null ? "." + suffix : "");

Expected message code according to documentation:

• problemDetail.detail.org.springframework.web.bind.MethodArgumentNotValidException

Actual message code that gets resolved

• problemDetail.org.springframework.web.bind.MethodArgumentNotValidException

[snicoll]

Closing in favor of PR #32446