huskies: merge 572_story_edit_criterion_mcp_tool_to_update_acceptance_criteria_text

server/src/http/workflow/story_ops.rs

@@ -126,6 +126,64 @@ pub fn check_criterion_in_file(
     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
+/// of checked state) and replaces its text with `new_text`.
+pub fn edit_criterion_in_file(
+    project_root: &Path,
+    story_id: &str,
+    criterion_index: usize,
+    new_text: &str,
+) -> 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()
+        .map(|line| {
+            let trimmed = line.trim();
+            let prefix = if trimmed.starts_with("- [ ] ") {
+                Some("- [ ] ")
+            } else if trimmed.starts_with("- [x] ") {
+                Some("- [x] ")
+            } else {
+                None
+            };
+            if let Some(p) = prefix {
+                if count == criterion_index {
+                    count += 1;
+                    found = true;
+                    let indent_len = line.len() - trimmed.len();
+                    let indent = &line[..indent_len];
+                    return format!("{indent}{p}{new_text}");
+                }
+                count += 1;
+            }
+            line.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(())
+}
+
 /// Add a new acceptance criterion to a story.
 ///
 /// Appends `- [ ] {criterion}` after the last existing criterion line in the