storkit: merge 440_refactor_consolidate_is_permission_approval_into_chat_util

server/src/chat/util.rs

@@ -3,6 +3,27 @@
 //! These functions are transport-agnostic helpers for processing chat messages:
 //! prefix stripping, bot-mention handling, and paragraph buffering.
 
+/// Returns `true` if the message body is an affirmative permission response.
+///
+/// Recognised affirmative tokens (case-insensitive): `yes`, `y`, `approve`,
+/// `allow`, `ok`. Anything else — including ambiguous text — is treated as
+/// denial (fail-closed).
+///
+/// A leading `@mention` (e.g. `"@timmy yes"`) is stripped before checking, so
+/// the bot name does not interfere with the result.
+pub fn is_permission_approval(body: &str) -> bool {
+    // Strip a leading @mention (e.g. "@timmy yes") so the bot name doesn't
+    // interfere with the check.
+    let trimmed = body
+        .trim()
+        .trim_start_matches('@')
+        .split_whitespace()
+        .last()
+        .unwrap_or("")
+        .to_ascii_lowercase();
+    matches!(trimmed.as_str(), "yes" | "y" | "approve" | "allow" | "ok")
+}
+
 /// Case-insensitive prefix strip that also requires the match to end at a
 /// word boundary (whitespace, punctuation, or end-of-string).
 pub fn strip_prefix_ci<'a>(text: &'a str, prefix: &str) -> Option<&'a str> {
@@ -190,6 +211,45 @@ pub fn normalize_line_breaks(text: &str) -> String {
 mod tests {
     use super::*;
 
+    // -- is_permission_approval ---------------------------------------------
+
+    #[test]
+    fn is_permission_approval_accepts_yes_variants() {
+        assert!(is_permission_approval("yes"));
+        assert!(is_permission_approval("Yes"));
+        assert!(is_permission_approval("YES"));
+        assert!(is_permission_approval("y"));
+        assert!(is_permission_approval("Y"));
+        assert!(is_permission_approval("approve"));
+        assert!(is_permission_approval("allow"));
+        assert!(is_permission_approval("ok"));
+        assert!(is_permission_approval("OK"));
+    }
+
+    #[test]
+    fn is_permission_approval_denies_no_and_other() {
+        assert!(!is_permission_approval("no"));
+        assert!(!is_permission_approval("No"));
+        assert!(!is_permission_approval("n"));
+        assert!(!is_permission_approval("deny"));
+        assert!(!is_permission_approval("reject"));
+        assert!(!is_permission_approval("maybe"));
+        assert!(!is_permission_approval(""));
+        assert!(!is_permission_approval("yes please do it"));
+    }
+
+    #[test]
+    fn is_permission_approval_strips_at_mention_prefix() {
+        assert!(is_permission_approval("@timmy yes"));
+        assert!(!is_permission_approval("@timmy no"));
+    }
+
+    #[test]
+    fn is_permission_approval_handles_whitespace() {
+        assert!(is_permission_approval("  yes  "));
+        assert!(is_permission_approval("\tyes\n"));
+    }
+
     // -- strip_prefix_ci ----------------------------------------------------
 
     #[test]