Fix syntax error when comment appears between index and table call

CHANGELOG.md

@@ -11,6 +11,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 - Added flag `--no-ignore-vcs` to continue formatting files listed in a `.gitignore` file, instead of skipping over them ([#895](https://github.com/JohnnyMorganz/StyLua/issues/895))
 
+### Fixed
+
+- Fixed syntax error in output when a single-line comment appears between an index suffix and a table call argument, e.g. `foo.bar -- comment { }` ([#873](https://github.com/JohnnyMorganz/StyLua/issues/873))
+
 ## [2.3.1] - 2025-11-01
 
 ### Fixed

src/formatters/functions.rs

@@ -1141,10 +1141,18 @@ pub fn format_function_call(
 
         let mut suffix = format_suffix(ctx, suffix, current_shape, ambiguous_next_suffix);
 
+        // Check if the previous suffix has trailing single-line comments.
+        // If it does, we MUST hang the AnonymousCall to avoid the opening parenthesis being commented out
+        let previous_suffix_has_trailing_singleline_comment = formatted_suffixes
+            .last()
+            .map(|s: &Suffix| s.has_trailing_comments(CommentSearch::Single))
+            .unwrap_or(false);
+
         // Hang the call, but don't hang if the previous suffix was an index and this is an anonymous call, i.e. `.foo()`
         if will_hang
             && !(previous_suffix_was_index
-                && matches!(suffix, Suffix::Call(Call::AnonymousCall(_))))
+                && matches!(suffix, Suffix::Call(Call::AnonymousCall(_)))
+                && !previous_suffix_has_trailing_singleline_comment)
         {
             suffix = trivia_util::prepend_newline_indent(ctx, &suffix, current_shape);
         }

tests/inputs/hang-call-chain-comments-4.lua

@@ -0,0 +1,15 @@
+-- https://github.com/JohnnyMorganz/StyLua/issues/873
+
+x = a.b -- comment
+{
+  y
+}
+
+console.dialog = iup.dialog
+{
+  iup.hbox -- use it to inherit margins
+  {
+    console.prompt,
+  },
+  title = "Command:",
+}

tests/snapshots/tests__standard@hang-call-chain-comments-4.lua.snap

@@ -0,0 +1,21 @@
+---
+source: tests/tests.rs
+expression: "format(&contents, LuaVersion::Lua51)"
+input_file: tests/inputs/hang-call-chain-comments-4.lua
+---
+-- https://github.com/JohnnyMorganz/StyLua/issues/873
+
+x = a
+	.b -- comment
+	({
+		y,
+	})
+
+console.dialog = iup.dialog({
+	iup
+		.hbox -- use it to inherit margins
+		({
+			console.prompt,
+		}),
+	title = "Command:",
+})