test: fix test case

Author: zombieJ

src/Preview/CloseBtn.tsx

@@ -9,10 +9,6 @@ export interface CloseBtnProps {
 export default function CloseBtn(props: CloseBtnProps) {
   const { prefixCls, icon, onClick } = props;
 
-  if (icon === false || icon === null) {
-    return null;
-  }
-
   return (
     <button className={`${prefixCls}-close`} onClick={onClick}>
       {icon}

src/Preview/index.tsx

@@ -421,11 +421,13 @@ const Preview: React.FC<PreviewProps> = props => {
               </div>
 
               {/* Close Button */}
-              <CloseBtn
-                prefixCls={prefixCls}
-                icon={closeIcon === false ? closeIcon : closeIcon || icons.close}
-                onClick={onClose}
-              />
+              {closeIcon !== false && closeIcon !== null && (
+                <CloseBtn
+                  prefixCls={prefixCls}
+                  icon={closeIcon === true ? icons.close : closeIcon || icons.close}
+                  onClick={onClose}
+                />
+              )}
 
               {/* Switch prev or next */}
               {showLeftOrRightSwitches && (

tests/preview.test.tsx

@@ -660,7 +660,7 @@ describe('Preview', () => {
       }),
     );
 
-    expect(container.querySelector('.rc-image-preview-close')).toBeFalsy();
+    expect(document.querySelector('.rc-image-preview-close')).toBeFalsy();
   });
 
   it('Customize Group preview props', () => {