From ce2e13d9e4e0c1c6396f17e8c4012fbbf50629f0 Mon Sep 17 00:00:00 2001
From: Sipke Schoorstra <sipkeschoorstra@outlook.com>
Date: Wed, 28 Apr 2021 22:22:55 +0200
Subject: [PATCH] Prevent dagre error by checking if source node actually
 exists before creating edge

---
 .../tree/elsa-designer-tree/elsa-designer-tree.tsx     | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/src/designer/elsa-workflows-studio/src/components/designers/tree/elsa-designer-tree/elsa-designer-tree.tsx b/src/designer/elsa-workflows-studio/src/components/designers/tree/elsa-designer-tree/elsa-designer-tree.tsx
index 02299c499..565c92474 100644
--- a/src/designer/elsa-workflows-studio/src/components/designers/tree/elsa-designer-tree/elsa-designer-tree.tsx
+++ b/src/designer/elsa-workflows-studio/src/components/designers/tree/elsa-designer-tree/elsa-designer-tree.tsx
@@ -338,7 +338,15 @@ export class ElsaWorkflowDesigner {
     });
 
     this.workflowModel.connections.forEach(({sourceId, targetId, outcome}) => {
-      this.graph.setEdge(`${sourceId}/${outcome}`, targetId, {arrowhead: 'undirected'});
+      const sourceName = `${sourceId}/${outcome}`;
+      
+      if(!this.graph.hasNode(sourceName))
+      {
+        console.warn(`No source node with ID '${sourceName}' exists.`);
+        return;
+      }
+      
+      this.graph.setEdge(sourceName, targetId, {arrowhead: 'undirected'});
     });
   }