migrate VisualViewport to ts

src/libs/VisualViewport/index.native.js → src/libs/VisualViewport/index.native.ts

@@ -1,10 +1,8 @@
+import AddViewportResizeListener from './types';
+
 /**
  * Visual Viewport is not available on native, so return an empty function.
- *
- * @returns {Function}
  */
-function addViewportResizeListener() {
-    return () => {};
-}
+const addViewportResizeListener: AddViewportResizeListener = () => () => {};
 
 export default addViewportResizeListener;

src/libs/VisualViewport/index.js → src/libs/VisualViewport/index.ts

@@ -1,16 +1,15 @@
+import AddViewportResizeListener from './types';
+
 /**
  * Add a visual viewport resize listener if available. Return a function to remove the listener.
- *
- * @param {Function} onViewportResize
- * @returns {Function}
  */
-function addViewportResizeListener(onViewportResize) {
+const addViewportResizeListener: AddViewportResizeListener = (onViewportResize) => {
     if (!window.visualViewport) {
         return () => {};
     }
 
     window.visualViewport.addEventListener('resize', onViewportResize);
-    return () => window.visualViewport.removeEventListener('resize', onViewportResize);
-}
+    return () => window.visualViewport?.removeEventListener('resize', onViewportResize);
+};
 
 export default addViewportResizeListener;

src/libs/VisualViewport/types.ts

@@ -0,0 +1,3 @@
+type AddViewportResizeListener = (onViewportResize: (e: Event) => void) => () => void;
+
+export default AddViewportResizeListener;