From 12d1cdf8f1c4dcd8c258134a296dfedbd1d9198e Mon Sep 17 00:00:00 2001
From: Guilhem <guilhemlemouel@gmail.com>
Date: Wed, 4 Mar 2026 12:55:28 +0000
Subject: [PATCH] fix(frontend): guard data.module.value access in ModuleNode

When rapidly clicking expand/collapse on a subflow, the graph rebuilds
and data.module can be transiently undefined. Add optional chaining to
prevent "Cannot read properties of undefined (reading 'value')" errors.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
---
 .../graph/renderers/nodes/ModuleNode.svelte           | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/frontend/src/lib/components/graph/renderers/nodes/ModuleNode.svelte b/frontend/src/lib/components/graph/renderers/nodes/ModuleNode.svelte
index df9631db0e..ba9c0659e1 100644
--- a/frontend/src/lib/components/graph/renderers/nodes/ModuleNode.svelte
+++ b/frontend/src/lib/components/graph/renderers/nodes/ModuleNode.svelte
@@ -93,7 +93,7 @@
 			moduleAction={data.moduleAction}
 			{menuItems}
 			annotation={flowJobs &&
-			(data.module.value.type === 'forloopflow' || data.module.value.type === 'whileloopflow')
+			(data.module?.value?.type === 'forloopflow' || data.module?.value?.type === 'whileloopflow')
 				? 'Iteration: ' +
 					((state?.selectedForloopIndex ?? 0) >= 0
 						? (state?.selectedForloopIndex ?? 0) + 1
@@ -130,15 +130,18 @@
 			onEditInput={data.eventHandlers.editInput}
 			flowJob={data.flowJob}
 			isOwner={data.isOwner}
-			maximizeSubflow={data.module.value.type == 'flow' && 'path' in data.module.value
+			maximizeSubflow={data.module?.value?.type == 'flow' && 'path' in data.module.value
 				? () => {
-						data.eventHandlers.expandSubflow(data.id, data.module.value['path'])
+						const path = data.module?.value && 'path' in data.module.value ? data.module.value['path'] as string : undefined
+						if (path) {
+							data.eventHandlers.expandSubflow(data.id, path)
+						}
 					}
 				: undefined}
 		/>
 
 		<div class="absolute -bottom-10 left-1/2 transform -translate-x-1/2 z-10">
-			{#if (data.module.value.type === 'branchall' || data.module.value.type === 'branchone') && data.insertable}
+			{#if (data.module?.value?.type === 'branchall' || data.module?.value?.type === 'branchone') && data.insertable}
 				<button
 					title="Add branch"
 					class="rounded text-secondary border hover:bg-surface-hover bg-surface p-1"