Function application_error_headers

pub fn application_error_headers(
    custom_user_data: &mut Vec<(String, String)>,
    application_error_code: String,
    application_error_payload: String,
) -> Result<(), String>

Helper function to add user-defined application error headers to a [Vec<(String, String)>] to be used as the custom_user_data on the Response.

custom_user_data can be an empty Vec or an existing Vec of custom user data. This function will add the application error headers to this Vec. application_error_code required to be a non-empty String. application_error_payload is optional and can be an empty String, in which case it is ignored and not added to custom_user_data. It is conventionally, but not necessarily, a stringified JSON object/value/array.

Returns Ok(()) if the properties are added to custom_user_data. If an error is returned, custom_user_data won’t get modified.

Errors

Returns an Error with the String “application_error_code cannot be empty” if application_error_code is an empty string.