guardian: move rejection rationales into turn extension state

codex-rs/ext/guardian/src/lib.rs

@@ -15,6 +15,7 @@ use codex_protocol::protocol::AskForApproval;
 
 mod approval_request;
 mod circuit_breaker;
+mod rejection_store;
 mod truncation;
 
 pub use approval_request::FormattedGuardianAction;
@@ -29,6 +30,8 @@ pub use circuit_breaker::GuardianRejectionCircuitBreaker;
 pub use circuit_breaker::GuardianRejectionCircuitBreakerAction;
 pub use circuit_breaker::MAX_CONSECUTIVE_GUARDIAN_DENIALS_PER_TURN;
 pub use circuit_breaker::MAX_RECENT_AUTO_REVIEW_DENIALS_PER_TURN;
+pub use rejection_store::GuardianRejection;
+pub use rejection_store::GuardianRejectionStore;
 pub use truncation::guardian_truncate_text;
 
 /// Guardian extension dependencies supplied by the host at construction time.

codex-rs/ext/guardian/src/rejection_store.rs

@@ -0,0 +1,37 @@
+use std::collections::HashMap;
+
+use codex_protocol::protocol::GuardianAssessmentDecisionSource;
+
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct GuardianRejection {
+    pub rationale: String,
+    pub source: GuardianAssessmentDecisionSource,
+}
+
+/// Rejection rationales awaiting delivery to callers for one turn.
+#[derive(Debug, Default, PartialEq, Eq)]
+pub struct GuardianRejectionStore {
+    rejections: HashMap<String, GuardianRejection>,
+}
+
+impl GuardianRejectionStore {
+    pub fn insert(
+        &mut self,
+        review_id: String,
+        rejection: GuardianRejection,
+    ) -> Option<GuardianRejection> {
+        self.rejections.insert(review_id, rejection)
+    }
+
+    pub fn remove(&mut self, review_id: &str) -> Option<GuardianRejection> {
+        self.rejections.remove(review_id)
+    }
+
+    pub fn contains(&self, review_id: &str) -> bool {
+        self.rejections.contains_key(review_id)
+    }
+}
+
+#[cfg(test)]
+#[path = "rejection_store_tests.rs"]
+mod tests;

codex-rs/ext/guardian/src/rejection_store_tests.rs

@@ -0,0 +1,30 @@
+use std::collections::HashMap;
+
+use codex_protocol::protocol::GuardianAssessmentDecisionSource;
+use pretty_assertions::assert_eq;
+
+use super::*;
+
+#[test]
+fn stores_rejections_by_review_id_and_removes_them_once() {
+    let rejection = GuardianRejection {
+        rationale: "unsafe command".to_string(),
+        source: GuardianAssessmentDecisionSource::Agent,
+    };
+    let mut store = GuardianRejectionStore::default();
+
+    assert_eq!(
+        store.insert("review-1".to_string(), rejection.clone()),
+        None
+    );
+    assert!(store.contains("review-1"));
+    assert_eq!(
+        store,
+        GuardianRejectionStore {
+            rejections: HashMap::from([("review-1".to_string(), rejection.clone())]),
+        }
+    );
+    assert_eq!(store.remove("review-1"), Some(rejection));
+    assert_eq!(store.remove("review-1"), None);
+    assert_eq!(store, GuardianRejectionStore::default());
+}