From 399a786986841b089cc68b5a5f06fc7b95e6b16a Mon Sep 17 00:00:00 2001
From: Perryvw <perryvw@users.noreply.github.com>
Date: Sat, 23 Sep 2023 17:23:37 +0200
Subject: [PATCH] Do not cause unrelated exception when throwing Error object
 in environment without debug module

---
 src/lualib/Error.ts     |  7 +++++--
 test/unit/error.spec.ts | 19 +++++++++++++++++++
 2 files changed, 24 insertions(+), 2 deletions(-)

diff --git a/src/lualib/Error.ts b/src/lualib/Error.ts
index fa1fa0bc0..ea9cba478 100644
--- a/src/lualib/Error.ts
+++ b/src/lualib/Error.ts
@@ -3,7 +3,10 @@ interface ErrorType {
     new (...args: any[]): Error;
 }
 
-function getErrorStack(constructor: () => any): string {
+function getErrorStack(constructor: () => any): string | undefined {
+    // If debug module is not available in this environment, don't bother trying to get stack trace
+    if (debug === undefined) return undefined;
+
     let level = 1;
     while (true) {
         const info = debug.getinfo(level, "f");
@@ -49,7 +52,7 @@ function initErrorClass(Type: ErrorType, name: string): any {
 export const Error: ErrorConstructor = initErrorClass(
     class implements Error {
         public name = "Error";
-        public stack: string;
+        public stack?: string;
 
         constructor(public message = "") {
             this.stack = getErrorStack((this.constructor as any).new);
diff --git a/test/unit/error.spec.ts b/test/unit/error.spec.ts
index 705ee77f0..388fee290 100644
--- a/test/unit/error.spec.ts
+++ b/test/unit/error.spec.ts
@@ -324,3 +324,22 @@ test.each([...builtinErrors, "CustomError"])("get stack from %s", errorType => {
     expect(stack).toMatch("innerFunction");
     expect(stack).toMatch("outerFunction");
 });
+
+test("still works without debug module", () => {
+    util.testFunction`
+        try
+        {
+            throw new Error("hello, world");
+        }
+        catch (e)
+        {
+            return e;
+        }
+    `
+        .setLuaHeader("debug = nil")
+        .expectToEqual({
+            message: "hello, world",
+            name: "Error",
+            stack: undefined,
+        });
+});