From 28a2f8c3e2093404f844a2742891252920b19089 Mon Sep 17 00:00:00 2001
From: draedful <aschetinin@yandex-team.ru>
Date: Wed, 1 Jul 2026 17:28:42 +0300
Subject: [PATCH 1/2] fix(connections): guard isPointInStroke before graph
 initialization

Prevent TypeError when mouse moves before connection Path2D is ready by
validating path/context in isPointInStroke and generating path on geometry update.

Co-authored-by: Cursor <cursoragent@cursor.com>
---
 .../canvas/connections/BlockConnection.ts     |  3 +-
 .../canvas/connections/bezierHelpers.test.ts  | 29 +++++++++++++++++++
 .../canvas/connections/bezierHelpers.ts       | 12 +++++++-
 3 files changed, 42 insertions(+), 2 deletions(-)
 create mode 100644 src/components/canvas/connections/bezierHelpers.test.ts

diff --git a/src/components/canvas/connections/BlockConnection.ts b/src/components/canvas/connections/BlockConnection.ts
index 581d6f7b..7390ee05 100644
--- a/src/components/canvas/connections/BlockConnection.ts
+++ b/src/components/canvas/connections/BlockConnection.ts
@@ -33,7 +33,7 @@ export class BlockConnection<T extends TConnection>
 {
   public readonly cursor = "pointer";
 
-  protected path2d: Path2D;
+  protected path2d: Path2D = new Path2D();
 
   protected labelGeometry: { x: number; y: number; width: number; height: number } | undefined = undefined;
 
@@ -238,6 +238,7 @@ export class BlockConnection<T extends TConnection>
     this.geometry.x2 = this.connectionPoints[1].x;
     this.geometry.y2 = this.connectionPoints[1].y;
 
+    this.generatePath();
     this.applyShape();
   }
 
diff --git a/src/components/canvas/connections/bezierHelpers.test.ts b/src/components/canvas/connections/bezierHelpers.test.ts
new file mode 100644
index 00000000..a65dfc73
--- /dev/null
+++ b/src/components/canvas/connections/bezierHelpers.test.ts
@@ -0,0 +1,29 @@
+import { isPointInStroke } from "./bezierHelpers";
+
+describe("isPointInStroke", () => {
+  it("returns false when path is undefined", () => {
+    const ctx = document.createElement("canvas").getContext("2d");
+
+    expect(isPointInStroke(ctx, undefined, 0, 0)).toBe(false);
+  });
+
+  it("returns false when path is not a Path2D instance", () => {
+    const ctx = document.createElement("canvas").getContext("2d");
+
+    expect(isPointInStroke(ctx, {} as Path2D, 0, 0)).toBe(false);
+  });
+
+  it("returns false when context is missing", () => {
+    const path = new Path2D();
+
+    expect(isPointInStroke(null, path, 0, 0)).toBe(false);
+  });
+
+  it("does not throw when path is invalid", () => {
+    const ctx = document.createElement("canvas").getContext("2d");
+
+    expect(() => isPointInStroke(ctx, undefined, 0, 0)).not.toThrow();
+    expect(() => isPointInStroke(ctx, {} as Path2D, 0, 0)).not.toThrow();
+    expect(() => isPointInStroke(null, new Path2D(), 0, 0)).not.toThrow();
+  });
+});
diff --git a/src/components/canvas/connections/bezierHelpers.ts b/src/components/canvas/connections/bezierHelpers.ts
index c0e9ee2f..ab08a04f 100644
--- a/src/components/canvas/connections/bezierHelpers.ts
+++ b/src/components/canvas/connections/bezierHelpers.ts
@@ -57,7 +57,17 @@ export function getPointOfBezierCurve(
   /* eslint-enable no-restricted-properties */
 }
 
-export function isPointInStroke(ctx: CanvasRenderingContext2D, path: Path2D, x: number, y: number, threshold?: number) {
+export function isPointInStroke(
+  ctx: CanvasRenderingContext2D | undefined | null,
+  path: Path2D | undefined | null,
+  x: number,
+  y: number,
+  threshold?: number,
+): boolean {
+  if (!ctx || !path || !(path instanceof Path2D)) {
+    return false;
+  }
+
   const l = ctx.lineWidth;
   if (threshold) {
     ctx.lineWidth = threshold;

From dca32fdb4b078430351ab726453d0ccf0b75012d Mon Sep 17 00:00:00 2001
From: draedful <aschetinin@yandex-team.ru>
Date: Wed, 1 Jul 2026 18:49:47 +0300
Subject: [PATCH 2/2] fix(connections): fix prettier trailing comma in
 isPointInStroke

Co-authored-by: Cursor <cursoragent@cursor.com>
---
 src/components/canvas/connections/bezierHelpers.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/components/canvas/connections/bezierHelpers.ts b/src/components/canvas/connections/bezierHelpers.ts
index ab08a04f..4aa6014e 100644
--- a/src/components/canvas/connections/bezierHelpers.ts
+++ b/src/components/canvas/connections/bezierHelpers.ts
@@ -62,7 +62,7 @@ export function isPointInStroke(
   path: Path2D | undefined | null,
   x: number,
   y: number,
-  threshold?: number,
+  threshold?: number
 ): boolean {
   if (!ctx || !path || !(path instanceof Path2D)) {
     return false;