huskies: merge 573_story_remove_criterion_mcp_tool_to_delete_an_acceptance_criterion

server/src/http/workflow/story_ops.rs

@@ -126,6 +126,53 @@ pub fn check_criterion_in_file(
     Ok(())
 }
 
+/// Remove an acceptance criterion from a story by its 0-based index (counting all criteria,
+/// both checked and unchecked). Returns an error if the index is out of range.
+pub fn remove_criterion_from_file(
+    project_root: &Path,
+    story_id: &str,
+    criterion_index: usize,
+) -> Result<(), String> {
+    let contents = read_story_content(project_root, story_id)?;
+
+    let mut count: usize = 0;
+    let mut found = false;
+    let new_lines: Vec<String> = contents
+        .lines()
+        .filter(|line| {
+            let trimmed = line.trim();
+            if trimmed.starts_with("- [ ] ") || trimmed.starts_with("- [x] ") {
+                if count == criterion_index {
+                    count += 1;
+                    found = true;
+                    return false;
+                }
+                count += 1;
+            }
+            true
+        })
+        .map(|s| s.to_string())
+        .collect();
+
+    if !found {
+        return Err(format!(
+            "Criterion index {criterion_index} out of range. Story '{story_id}' has \
+             {count} criteria (indices 0..{}).",
+            count.saturating_sub(1)
+        ));
+    }
+
+    let mut new_str = new_lines.join("\n");
+    if contents.ends_with('\n') {
+        new_str.push('\n');
+    }
+
+    let stage = story_stage(story_id).unwrap_or_else(|| "2_current".to_string());
+    write_story_content(project_root, story_id, &stage, &new_str);
+
+    Ok(())
+}
+
 /// Edit the text of an existing acceptance criterion without changing its checked state.
 ///
 /// Finds the criterion at `criterion_index` (0-based, counting all criteria regardless
@@ -578,6 +625,61 @@ mod tests {
         assert!(result.unwrap_err().contains("Acceptance Criteria"));
     }
 
+    // ── remove_criterion_from_file tests ──────────────────────────────────────
+
+    #[test]
+    fn remove_criterion_removes_by_index() {
+        let tmp = tempfile::tempdir().unwrap();
+        setup_story_in_fs(
+            tmp.path(),
+            "20_remove_test",
+            &story_with_ac_section(&["First", "Second", "Third"]),
+        );
+
+        remove_criterion_from_file(tmp.path(), "20_remove_test", 1).unwrap();
+
+        let contents = read_story_content(tmp.path(), "20_remove_test").unwrap();
+        assert!(contents.contains("- [ ] First"), "First should remain");
+        assert!(!contents.contains("Second"), "Second should be removed");
+        assert!(contents.contains("- [ ] Third"), "Third should remain");
+    }
+
+    #[test]
+    fn remove_criterion_shifts_indices() {
+        let tmp = tempfile::tempdir().unwrap();
+        setup_story_in_fs(
+            tmp.path(),
+            "21_remove_test",
+            &story_with_ac_section(&["A", "B", "C"]),
+        );
+
+        remove_criterion_from_file(tmp.path(), "21_remove_test", 0).unwrap();
+
+        let contents = read_story_content(tmp.path(), "21_remove_test").unwrap();
+        assert!(!contents.contains("- [ ] A"), "A should be removed");
+        assert!(contents.contains("- [ ] B"), "B should remain");
+        assert!(contents.contains("- [ ] C"), "C should remain");
+        // B is now at index 0, C at index 1 — verify by removing B next
+        remove_criterion_from_file(tmp.path(), "21_remove_test", 0).unwrap();
+        let contents2 = read_story_content(tmp.path(), "21_remove_test").unwrap();
+        assert!(!contents2.contains("- [ ] B"), "B should now be removed");
+        assert!(contents2.contains("- [ ] C"), "C should still remain");
+    }
+
+    #[test]
+    fn remove_criterion_out_of_range_returns_error() {
+        let tmp = tempfile::tempdir().unwrap();
+        setup_story_in_fs(
+            tmp.path(),
+            "22_remove_test",
+            &story_with_ac_section(&["Only"]),
+        );
+
+        let result = remove_criterion_from_file(tmp.path(), "22_remove_test", 5);
+        assert!(result.is_err(), "should fail for out-of-range index");
+        assert!(result.unwrap_err().contains("out of range"));
+    }
+
     // ── update_story_in_file tests ─────────────────────────────────────────────
 
     #[test]