fix(parse): ignore mid-line '@' in doc cmnts

crates/parse/src/parser/mod.rs

@@ -749,7 +749,7 @@ impl<'sess, 'ast> Parser<'sess, 'ast> {
         while let Some((is_doc, kind, symbol)) = self.token.comment() {
             if is_doc {
                 let natspec = if let Some(items) =
-                    parse_natspec(self.token.span, symbol, self.in_yul, self.dcx())
+                    parse_natspec(self.token.span, symbol, kind, self.in_yul, self.dcx())
                 {
                     self.alloc_smallvec(items)
                 } else {
@@ -1039,6 +1039,7 @@ impl<'sess, 'ast> Parser<'sess, 'ast> {
 fn parse_natspec(
     comment_span: Span,
     comment_symbol: Symbol,
+    comment_kind: ast::CommentKind,
     in_yul: bool,
     dcx: &DiagCtxt,
 ) -> Option<SmallVec<[ast::NatSpecItem; 6]>> {
@@ -1084,10 +1085,27 @@ fn parse_natspec(
         }
     }
 
+    // Check if '@' is located at the logical start of the line.
+    let is_line_start = |line_start: usize, at_pos: usize| {
+        match comment_kind {
+            // can only be followed by whitespace
+            ast::CommentKind::Line => bytes[line_start..at_pos].trim_ascii().is_empty(),
+
+            // can only be followed by whitespaces + ('*') + whitespaces
+            ast::CommentKind::Block => {
+                let trimmed = &bytes[line_start..at_pos].trim_ascii_start();
+                trimmed.is_empty()
+                    || (trimmed.starts_with(b"*") && trimmed[1..].trim_ascii_end().is_empty())
+            }
+        }
+    };
+
     // Iterate over each line and look for tags.
     let mut prev_line_end = 0;
     for line_end in memchr::memchr_iter(b'\n', bytes).chain(std::iter::once(bytes.len())) {
-        if let Some(tag_offset) = memchr::memchr(b'@', &bytes[line_start..line_end]) {
+        if let Some(tag_offset) = memchr::memchr(b'@', &bytes[line_start..line_end])
+            && is_line_start(line_start, line_start + tag_offset)
+        {
             let tag_start = line_start + tag_offset + 1;
             flush_item(&mut items, &mut kind, &mut span, content_start, prev_line_end);
 

tests/ui/natspec/natspec.sol

@@ -89,4 +89,13 @@ contract YulContext {
 }
 
 /// @ author whitespace before tag is valid
-contract Repro {}
+/// @notice it is valid to add '@'s in the middle of a comment
+///   * Solve: 2yr @ 5% == 1yr @ 0% + 1yr @ x => x = 10.00%
+contract ReproLineComment {}
+
+/**
+* @ author whitespace before tag is valid
+* @notice it is valid to add '@'s in the middle of a comment
+*    Solve: 2yr @ 5% == 1yr @ 0% + 1yr @ x => x = 10.00%
+**/
+contract ReproBlockComment {}