Error message caught by Axios is undefined in production, but works locally?

Issue

I have a function that sends an axios rrequest to my springboot backend.

  async createUser(user) {
    return axios.post(API_BASE_URL + "users/register", user).catch((error) => {
      console.log("the error: " + error.response.data.message);
      throw error.response.data.message;
    });
  }

For some reason, when I run the project locally, I am able to get the error message above, but when I deploy the project to production, the error message is undefined.

Example of the above print statement^:

Error message when ran locally: the error: Email must be a work email. The email zx is NOT allowed.

Error message when deployed: the error: undefined

Code from my backend: The controller:

    @PostMapping("/api/users/register")
    public User registerUser(@RequestBody User user) {
        return userServices.createUser(user);
    }

    public User createUser(User userDetails) {
        if (Boolean.TRUE.equals(emailExists(userDetails.getEmail()))) {
            throw new DuplicateResourceException(
                    "There is already an account with that email address: " +
                            userDetails.getEmail());
        }
        if (!userDetails.getEmail().toLowerCase().endsWith("@company.com")) {
            throw new NotAllowedException(
                    "Email must be a work email. The email " +
                            userDetails.getEmail() + " is NOT allowed.");
        }
        if (!userDetails.getCompanyPasscode().equals(env.getProperty("company.passcode"))) {
            throw new NotAllowedException(
                    "Incorrect company passcode");
        }
        User user = new User();
        user.setEmail(userDetails.getEmail());
        user.setPassword(passwordEncoder.encode(userDetails.getPassword()));
        return userRepo.save(user);
    }

So if you look that the above function, you can see that when I run the project locally, I can get the NotAllowedException to be thrown back to my frontend, but not when deplpyed.

I read online that it could be due to a CORS header issue, but I don't think so because this is my CORS configuration and it still isn't working:

    @Bean
    CorsConfigurationSource corsConfigurationSource() {
        final CorsConfiguration config = new CorsConfiguration();

        config.setAllowedMethods(Arrays.asList("GET", "POST", "OPTIONS", "DELETE", "PUT", "PATCH"));
        config.setAllowedHeaders(Arrays.asList("*"));
        config.setAllowedOrigins(Arrays.asList("*"));

        UrlBasedCorsConfigurationSource source = new UrlBasedCorsConfigurationSource();
        source.registerCorsConfiguration("/**", new CorsConfiguration().applyPermitDefaultValues());
        return source;

    }

This is an example of one of my custom Exception classes:

import org.springframework.http.HttpStatus;
import org.springframework.web.bind.annotation.ResponseStatus;

@ResponseStatus(value = HttpStatus.BAD_REQUEST)
public class NotAllowedException extends RuntimeException {

    private static final long serialVersionUID = 1L;

    public NotAllowedException(String message) {
        super(message);
    }
}

Solution

I believe that you should enable this application properties in application configuration.

server:
  error:
  include-message: always

More details here.

Answered By - Vinh Truong