fix(connections): guard isPointInStroke before graph initialization

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();
   }
 

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();
+  });
+});

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;