fix: Should not trigger observe repeatly

fix ant-design/ant-design#19129

Author: zombieJ

src/index.tsx

@@ -31,7 +31,7 @@ class ReactResizeObserver extends React.Component<
 
   childNode: RefNode = null;
 
-  currentElement: HTMLElement | null = null;
+  currentElement: Element | null = null;
 
   state = {
     width: 0,
@@ -64,6 +64,7 @@ class ReactResizeObserver extends React.Component<
     const elementChanged = element !== this.currentElement;
     if (elementChanged) {
       this.destroyObserver();
+      this.currentElement = element;
     }
 
     if (!this.resizeObserver && element) {

tests/index.spec.js

@@ -83,6 +83,7 @@ describe('ResizeObserver', () => {
 
     wrapper.triggerResize();
 
+    expect(wrapper.instance().currentElement).toBeTruthy();
     expect(onResize).toHaveBeenCalled();
   });