From 8f6c7109d8e6245234a63f9d0e94eecef2dbd962 Mon Sep 17 00:00:00 2001
From: Michael Trosper <mtrosper36@gmail.com>
Date: Thu, 20 Aug 2026 08:10:02 -0600
Subject: [PATCH] Fix TypeError crash in GraphLaTeX renderer when nodes/links
 are missing

problemData.nodes.map() threw "Cannot read properties of undefined
(reading 'map')" whenever a frame arrived without a nodes or links
array, crashing DFA/NFA Acceptance visualizations. Normalize both to
[] before use, matching the same guard already in
StandardGraphSvgReact.js (the D3 graph renderer).

Fixes #168

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_011M2KW5z36iHV1StfmfeMvU
---
 components/Visualization/svgs/LaTeXGraphSvgReact.js | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/components/Visualization/svgs/LaTeXGraphSvgReact.js b/components/Visualization/svgs/LaTeXGraphSvgReact.js
index 077d63aa..b0f56302 100644
--- a/components/Visualization/svgs/LaTeXGraphSvgReact.js
+++ b/components/Visualization/svgs/LaTeXGraphSvgReact.js
@@ -51,7 +51,7 @@ function LaTeXGraphSvgReact({ problemData }) {
 
       const rand = seededRandom(12345);
 
-      const nodes = problemData.nodes.map((n) => ({
+      const nodes = (problemData.nodes || []).map((n) => ({
         ...n,
         x: rand() * 10,
         y: rand() * 10,
@@ -59,7 +59,7 @@ function LaTeXGraphSvgReact({ problemData }) {
         vy: 0,
       }));
 
-      const links = problemData.links;
+      const links = problemData.links || [];
 
       const iterations = 200;
       const repulsion = 0.4;