Add safe default fallback for scrollEventThrottle and remove return from queueMicrotask

src/reanimated2/NativeReanimated/index.ts

@@ -2,11 +2,6 @@ import reanimatedJS from '../js-reanimated';
 import { shouldBeUseWeb } from '../PlatformChecker';
 import { NativeReanimated } from './NativeReanimated';
 
-let exportedModule;
-if (shouldBeUseWeb()) {
-  exportedModule = reanimatedJS;
-} else {
-  exportedModule = new NativeReanimated();
-}
-
-export default exportedModule as NativeReanimated;
+export default (shouldBeUseWeb()
+  ? reanimatedJS
+  : new NativeReanimated()) as NativeReanimated;

src/reanimated2/component/FlatList.tsx

@@ -62,6 +62,15 @@ export const ReanimatedFlatList = forwardRef(
         : styles.verticallyInverted
       : undefined;
 
+    // Set default scrollEventThrottle, because user expects
+    // to have continuous scroll events and
+    // react-native defaults it to 50 for FlatLists.
+    // We set it to 1 so we have peace until
+    // there are 960 fps screens.
+    if (!('scrollEventThrottle' in restProps)) {
+      restProps.scrollEventThrottle = 1;
+    }
+
     const cellRenderer = React.useMemo(
       () => createCellRenderer(itemLayoutAnimation, cellStyle),
       [cellStyle]

src/reanimated2/component/ScrollView.tsx

@@ -41,10 +41,12 @@ export const AnimatedScrollView: AnimatedScrollView = forwardRef(
       );
     }
 
-    if (!restProps.scrollEventThrottle) {
-      // Set default scrollEventThrottle to 8, because user expects
-      // to have continuous scroll events
-      restProps.scrollEventThrottle = 8;
+    // Set default scrollEventThrottle, because user expects
+    // to have continuous scroll events.
+    // We set it to 1 so we have peace until
+    // there are 960 fps screens.
+    if (!('scrollEventThrottle' in restProps)) {
+      restProps.scrollEventThrottle = 1;
     }
 
     return <AnimatedScrollViewComponent ref={aref} {...restProps} />;

src/reanimated2/threads.ts

@@ -16,11 +16,8 @@ export function setupMicrotasks() {
 
   let microtasksQueue: Array<() => void> = [];
   let isExecutingMicrotasksQueue = false;
-
-  // @ts-ignore – typescript expects this to conform to NodeJS definition and expects the return value to be NodeJS.Immediate which is an object and not a number
-  global.queueMicrotask = (callback: () => void): number => {
+  global.queueMicrotask = (callback: () => void) => {
     microtasksQueue.push(callback);
-    return -1;
   };
 
   global.__callMicrotasks = () => {