初始化

client/test/domrect.js

@@ -0,0 +1,16 @@
+// mock class
+
+export class DOMRect {
+  constructor(x, y, width, height) {
+    this.x = x;
+    this.y = y;
+    this.width = width;
+    this.height = height;
+  }
+  get left() {
+    return this.x;
+  }
+  get top() {
+    return this.y;
+  }
+}