From 24257de8a631cd61604eb08015e32cf2fab4acc7 Mon Sep 17 00:00:00 2001
From: darshanr0107 <darshan@mermaid.com>
Date: Tue, 24 Jun 2025 14:50:20 +0530
Subject: [PATCH] fix state diagram edge label position

---
 .../rendering-util/rendering-elements/edges.js  |  4 ++++
 packages/mermaid/src/utils.ts                   | 17 +++++++++++++++++
 2 files changed, 21 insertions(+)

diff --git a/packages/mermaid/src/rendering-util/rendering-elements/edges.js b/packages/mermaid/src/rendering-util/rendering-elements/edges.js
index a97668d5f..154040d87 100644
--- a/packages/mermaid/src/rendering-util/rendering-elements/edges.js
+++ b/packages/mermaid/src/rendering-util/rendering-elements/edges.js
@@ -638,6 +638,10 @@ export const insertEdge = function (elem, edge, clusterDb, diagramType, startNod
 
   addEdgeMarkers(svgPath, edge, url, id, diagramType, strokeColor);
 
+  if (!utils.isPointInDAttr(points, svgPath.attr('d'))) {
+    pointsHasChanged = true;
+  }
+
   let paths = {};
   if (pointsHasChanged) {
     paths.updatedPath = points;
diff --git a/packages/mermaid/src/utils.ts b/packages/mermaid/src/utils.ts
index 6ed935cf6..61157f827 100644
--- a/packages/mermaid/src/utils.ts
+++ b/packages/mermaid/src/utils.ts
@@ -884,6 +884,7 @@ export default {
   runFunc,
   entityDecode,
   insertTitle,
+  isPointInDAttr,
   parseFontSize,
   InitIDGenerator,
 };
@@ -960,3 +961,19 @@ export function handleUndefinedAttr(
 ) {
   return attrValue ?? null;
 }
+
+export function isPointInDAttr(points: Point[], dAttr: string) {
+  if (!points || points.length < 2 || !dAttr) {
+    return false;
+  }
+
+  const point = points[1];
+  const roundedX = Math.round(point.x);
+  const roundedY = Math.round(point.y);
+
+  const sanitizedD = dAttr.replace(/(\d+\.\d+)/g, (match) =>
+    Math.round(parseFloat(match)).toString()
+  );
+
+  return sanitizedD.includes(roundedX.toString()) || sanitizedD.includes(roundedY.toString());
+}