Request current scroll position on initial mount

Author: sebmarkbage

packages/react-devtools-shared/src/backend/views/Highlighter/index.js

@@ -29,6 +29,7 @@ export default function setupHighlighter(
   bridge.addListener('startInspectingHost', startInspectingHost);
   bridge.addListener('stopInspectingHost', stopInspectingHost);
   bridge.addListener('scrollTo', scrollDocumentTo);
+  bridge.addListener('requestScrollPosition', sendScroll);
 
   let applyingScroll = false;
 

packages/react-devtools-shared/src/bridge.js

@@ -256,6 +256,7 @@ type FrontendEvents = {
   startProfiling: [StartProfilingParams],
   stopInspectingHost: [boolean],
   scrollTo: [{x: number, y: number}],
+  requestScrollPosition: [],
   stopProfiling: [],
   storeAsGlobal: [StoreAsGlobalParams],
   updateComponentFilters: [Array<ComponentFilter>],

packages/react-devtools-shared/src/devtools/views/SuspenseTab/SuspenseTab.js

@@ -248,6 +248,8 @@ function SynchronizedScrollContainer({
   useEffect(() => {
     const callback = scrollContainerTo;
     bridge.addListener('scrollTo', callback);
+    // Ask for the current scroll position when we mount so we can attach ourselves to it.
+    bridge.send('requestScrollPosition');
     return () => bridge.removeListener('scrollTo', callback);
   }, [bridge]);