TS Strict ButtonGroup (adobe#3185)

* TS Strict ButtonGroup

Author: snowystinger

packages/@react-aria/utils/src/useResizeObserver.ts

@@ -5,7 +5,7 @@ function hasResizeObserver() {
 }
 
 type useResizeObserverOptionsType<T> = {
-  ref: RefObject<T>,
+  ref: RefObject<T | undefined>,
   onResize: () => void
 }
 

packages/@react-spectrum/buttongroup/src/ButtonGroup.tsx

@@ -75,7 +75,9 @@ function ButtonGroup(props: SpectrumButtonGroupProps, ref: DOMRef<HTMLDivElement
   // 2. External changes: buttongroup won't change size due to any parents changing size, so listen to its container for size changes to figure out if we should remeasure
   let parent = useRef<HTMLElement>();
   useLayoutEffect(() => {
-    parent.current = domRef.current.parentElement;
+    if (domRef.current) {
+      parent.current = domRef.current.parentElement as HTMLElement;
+    }
   }, [domRef.current]);
   useResizeObserver({ref: parent, onResize: checkForOverflow});
 

tsconfig.json

@@ -33,7 +33,7 @@
       {
         "name": "typescript-strict-plugin",
         "paths": [
-          "./packages/@react-spectrum/button/s",
+          "./packages/@react-spectrum/button",
         ]
       }
     ]