Function error_context 

pub fn error_context(status: u16, headers: &Headers) -> ErrorContext

The diagnostic context of an HTTP error response, read from its status and headers:

• status;
• request_id from x-request-id or request-id;
• retry_after from Retry-After or retry-after-ms (see Headers::retry_after);
• server_retry_directive from x-should-retry: true or false; any other value is no directive.

Every bundled HTTP provider builds its error context here, so a header rule added later reaches third-party providers that call it too. Attach it with Error::with_context, which merges: it sets the fields read here, keeps the others, and never changes the message origin. A provider that names its request id or retry hint header differently sets that field after attaching this context (with_request_id, with_retry_after), so a standard header does not overwrite it.

use allama::Error;
use allama_http::{Headers, error_context, error_envelope, status_error};

fn map_http_error(status: u16, headers: &Headers, body: &str) -> Error {
    let error = status_error(status, format!("HTTP {status}"));
    error_envelope(body)
        .unwrap_or_default()
        .apply(error.with_context(error_context(status, headers)).authored())
        .with_body(body.to_owned())
}

let headers: Headers = [
    ("x-request-id", "req_1"),
    ("retry-after", "2"),
    ("x-should-retry", "false"),
]
.into_iter()
.collect();
let err = map_http_error(429, &headers, r#"{"error": {"message": "slow down"}}"#);
assert_eq!(err.status(), Some(429));
assert_eq!(err.request_id(), Some("req_1"));
assert_eq!(err.retry_after(), Some(std::time::Duration::from_secs(2)));
assert_eq!(err.server_retry_directive(), Some(false));
assert_eq!(err.upstream_message(), Some("slow down"));