Flatten fix (#68)

Ref
foundry-rs/foundry#6936 (comment)

Not sure why exactly this unwrap is failing, adding `None` variant
handling and some logs to debug it.

---------

Co-authored-by: Matthias Seitz <matthias.seitz@outlook.de>

src/flatten.rs

@@ -382,6 +382,7 @@ impl Flattener {
  /// We will either replace contract name or remove @inheritdoc tag completely to avoid
  /// generating invalid source code.
  fn update_inheritdocs(&self, top_level_names: &HashMap<usize, String>, updates: &mut Updates) {
+ trace!("updating @inheritdoc tags");
  for (path, ast) in &self.asts {
  // Collect all exported symbols for this source unit
  // @inheritdoc value is either one of those or qualified import path which we don't
@@ -434,7 +435,9 @@ impl Flattener {
  // slashes and we can't use if to find positions.
  let content: &str = &self.sources.get(path).unwrap().content[src_start..src_end];
  let tag_len = "@inheritdoc".len();
+
  if let Some(tag_start) = content.find("@inheritdoc") {
+ trace!("processing doc with content {:?}", content);
  if let Some(name_start) = content[tag_start + tag_len..]
  .find(|c| c != ' ')
  .map(|p| p + tag_start + tag_len)
@@ -445,15 +448,27 @@ impl Flattener {
  .unwrap_or(content.len());
 
  let name = &content[name_start..name_end];
+ trace!("found name {name}");
+
+ let mut new_name = None;
 
  if let Some(ast_id) = exported_symbols.get(name) {
- let new_name = top_level_names.get(ast_id).unwrap();
+ if let Some(name) = top_level_names.get(ast_id) {
+ new_name = Some(name);
+ } else {
+ trace!(identifiers=?top_level_names, "ast id {ast_id} cannot be matched to top-level identifier");
+ }
+ }
+
+ if let Some(new_name) = new_name {
+ trace!("updating tag value with {new_name}");
  updates.entry(path.to_path_buf()).or_default().insert((
  src_start + name_start,
  src_start + name_end,
  new_name.to_string(),
  ));
  } else {
+ trace!("name is unknown, removing @inheritdoc tag");
  updates.entry(path.to_path_buf()).or_default().insert((
  src_start + tag_start,
  src_start + name_end,