Fix generic pack crash (#404)

* Handle generic and variadic packs

* Update tests

* Update changelog

* Redo tests

CHANGELOG.md

@@ -5,6 +5,8 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
 ## [Unreleased]
+### Fixed
+- Fixed crashed due to unhandled generic type packs under the `luau` feature flag. ([#403](https://github.com/JohnnyMorganz/StyLua/issues/403))
 
 ## [0.12.4] - 2022-03-02
 ### Fixed

src/formatters/trivia_util.rs

@@ -192,6 +192,7 @@ pub fn type_info_trailing_trivia(type_info: &TypeInfo) -> Vec<Token> {
             let (_, end_brace) = arrows.tokens();
             end_brace.trailing_trivia().map(|x| x.to_owned()).collect()
         }
+        TypeInfo::GenericPack { ellipse, .. } => ellipse.trailing_trivia().cloned().collect(),
 
         TypeInfo::Intersection { right, .. } => type_info_trailing_trivia(right),
 
@@ -219,7 +220,7 @@ pub fn type_info_trailing_trivia(type_info: &TypeInfo) -> Vec<Token> {
 
         TypeInfo::Union { right, .. } => type_info_trailing_trivia(right),
         TypeInfo::Variadic { type_info, .. } => type_info_trailing_trivia(type_info),
-
+        TypeInfo::VariadicPack { name, .. } => name.trailing_trivia().cloned().collect(),
         other => panic!("unknown node {:?}", other),
     }
 }

tests/inputs-luau/types-generic-pack.lua

@@ -0,0 +1,3 @@
+type X = {
+	useMemo: <T...>(nextCreate: () -> T..., deps: Array<any> | nil) -> T...,
+}

tests/snapshots/tests__luau@types-generic-pack.lua.snap

@@ -0,0 +1,10 @@
+---
+source: tests/tests.rs
+assertion_line: 30
+expression: format(&contents)
+
+---
+type X = {
+	useMemo: <T...>(nextCreate: () -> T..., deps: Array<any> | nil) -> T...,
+}
+