feat(canvas): 自由画布 - 增强空白起点、外观设置与节点连接体验 (#356)

web/test/canvas-connected-node-placement.test.ts

@@ -0,0 +1,13 @@
+import { describe, expect, it } from "bun:test";
+
+import { connectedNodeCenterFromEdgeDrop } from "@/lib/canvas/canvas-connected-node-placement";
+
+describe("connectedNodeCenterFromEdgeDrop", () => {
+    it("uses an output drop as the new target node's left-edge midpoint", () => {
+        expect(connectedNodeCenterFromEdgeDrop({ x: 900, y: 320 }, { width: 720, height: 405 }, "source")).toEqual({ x: 1260, y: 320 });
+    });
+
+    it("uses an input drop as the new source node's right-edge midpoint", () => {
+        expect(connectedNodeCenterFromEdgeDrop({ x: 900, y: 320 }, { width: 340, height: 120 }, "target")).toEqual({ x: 730, y: 320 });
+    });
+});