huskies: merge 619_story_service_common_consolidation_sweep

server/src/service/common/item_id.rs

@@ -0,0 +1,70 @@
+//! Pure helpers for pipeline item ID parsing.
+//!
+//! Pipeline item IDs share the format `{number}_{type}_{slug}`, e.g.
+//! `"42_story_foo"`, `"7_bug_bar"`, `"100_refactor_baz"`. The functions here
+//! extract or validate the leading numeric segment without performing any I/O.
+
+/// Extract the numeric prefix from a pipeline item ID.
+///
+/// Returns the leading digit sequence from IDs like `"42_story_foo"` → `"42"`.
+/// Returns `None` if the ID has no leading digit sequence.
+pub fn extract_item_number(item_id: &str) -> Option<&str> {
+    item_id
+        .split('_')
+        .next()
+        .filter(|s| !s.is_empty() && s.chars().all(|c| c.is_ascii_digit()))
+}
+
+#[allow(dead_code)]
+/// Return `true` if `item_id` has a valid `{digits}_` prefix format.
+///
+/// Valid: `"42_story_foo"`, `"1_bug_bar"`.
+/// Invalid: `"story_without_number"`, `""`, `"abc_story"`.
+pub fn has_valid_id_prefix(item_id: &str) -> bool {
+    extract_item_number(item_id).is_some()
+}
+
+// ── Tests ─────────────────────────────────────────────────────────────────────
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn extract_item_number_extracts_prefix() {
+        assert_eq!(extract_item_number("42_story_foo"), Some("42"));
+        assert_eq!(extract_item_number("1_bug_bar"), Some("1"));
+        assert_eq!(extract_item_number("100_refactor_baz"), Some("100"));
+        assert_eq!(
+            extract_item_number("261_story_bot_notifications"),
+            Some("261")
+        );
+        assert_eq!(extract_item_number("1_spike_research"), Some("1"));
+    }
+
+    #[test]
+    fn extract_item_number_returns_none_for_no_numeric_prefix() {
+        assert_eq!(extract_item_number("story_without_number"), None);
+        assert_eq!(extract_item_number("abc_story"), None);
+        assert_eq!(extract_item_number("abc_story_thing"), None);
+        assert_eq!(extract_item_number(""), None);
+    }
+
+    #[test]
+    fn extract_item_number_returns_none_for_empty_first_segment() {
+        // Leading underscore: first segment is "".
+        assert_eq!(extract_item_number("_story_thing"), None);
+    }
+
+    #[test]
+    fn has_valid_id_prefix_returns_true_for_valid_ids() {
+        assert!(has_valid_id_prefix("42_story_foo"));
+        assert!(has_valid_id_prefix("1_bug_bar"));
+    }
+
+    #[test]
+    fn has_valid_id_prefix_returns_false_for_invalid_ids() {
+        assert!(!has_valid_id_prefix("story_no_number"));
+        assert!(!has_valid_id_prefix(""));
+    }
+}