mod tests {
    use super::*;
    #[test]
    fn transformations_preserve_distinct_set_cookie_fields() {
        let source = r#"{"request":[],"response":[{"op":"remove","name":"server"},{"op":"set","name":"x-test","value":"one"},{"op":"append","name":"x-test","value":"two"},{"op":"append","name":"set-cookie","value":"b=2"}]}"#;
        let rules: HeaderRules = serde_json::from_str(source).unwrap();
        let compiled = rules.compile().unwrap();
        let mut headers = HeaderMap::new();
        headers.insert("server", "upstream".parse().unwrap());
        headers.append("set-cookie", "a=1".parse().unwrap());
        apply(&mut headers, &compiled.response);
        assert!(!headers.contains_key("server"));
        assert_eq!(headers.get_all("x-test").iter().count(), 2);
        assert_eq!(headers.get_all("set-cookie").iter().count(), 2);
    }
    #[test]
    fn transport_identity_and_crlf_are_rejected() {
        for name in [
            "Host",
            "Connection",
            "Content-Length",
            "x-forwarded-for",
            "Upgrade",
            "X-RustProxy-Backend",
            "X-Rust-Proxy-Backend",
            "X-RustProxy-Backend-Time",
            "X-Rust-Proxy-Backend-Time",
        ] {
            let rules = HeaderRules {
                request: vec![Rule {
                    op: Operation::Set,
                    name: name.into(),
                    value: Some("x".into()),
                }],
                response: vec![],
            };
            assert!(rules.compile().is_err(), "{name}");
            let response_rules = HeaderRules { request: vec![], response: rules.request };
            assert!(response_rules.compile().is_err(), "response {name}");
        }
        let rules = HeaderRules {
            request: vec![Rule {
                op: Operation::Set,
                name: "x-test".into(),
                value: Some("hello\r\ninjected: yes".into()),
            }],
            response: vec![],
        };
        assert!(rules.compile().is_err());
    }

    #[test]
    fn response_age_is_allowed_but_applied_only_at_wire_stage() {
        let request_age = HeaderRules {
            request: vec![Rule {
                op: Operation::Set,
                name: "Age".into(),
                value: Some("7".into()),
            }],
            response: vec![],
        };
        let request_compiled = request_age.compile().unwrap();
        let mut request_headers = HeaderMap::new();
        apply(&mut request_headers, &request_compiled.request);
        assert_eq!(request_headers["age"], "7");

        let response_age = HeaderRules {
            request: vec![],
            response: vec![Rule {
                op: Operation::Remove,
                name: "Age".into(),
                value: None,
            }],
        };
        let compiled = response_age.compile().unwrap();
        let mut headers = HeaderMap::new();
        headers.insert("age", HeaderValue::from_static("42"));
        apply(&mut headers, &compiled.response);
        assert_eq!(headers["age"], "42");
        apply_wire_age(&mut headers, &compiled.response);
        assert!(!headers.contains_key("age"));
    }

    #[test]
    fn response_age_keeps_0266_rule_compatibility() {
        let rules = HeaderRules {
            request: vec![],
            response: vec![
                Rule {
                    op: Operation::Set,
                    name: "age".into(),
                    value: Some("custom".into()),
                },
                Rule {
                    op: Operation::Append,
                    name: "age".into(),
                    value: Some("7".into()),
                },
            ],
        };
        let compiled = rules.compile().unwrap();
        let mut headers = HeaderMap::new();
        headers.insert("age", HeaderValue::from_static("42"));
        apply(&mut headers, &compiled.response);
        assert_eq!(headers["age"], "42");
        apply_wire_age(&mut headers, &compiled.response);
        assert_eq!(headers.get_all("age").iter().count(), 2);
    }
}