useTabster is unsafe for strict mode/concurrent rendering in React 18 #24085
Description
Tabster is created in useMemo from #23811 which is unsafe for concurrent rendering.
In general singletons will be problematic in concurrent rendering because there is no built in way to ensure a singleton constructor is called once:
// all the below call the `createSingleton` function twice on mount
React.useState(() => createSingleton());
React.useMemo(() => createSingleton(), []);
React.useEffect(() => {
createSingleton();
}, [])
React.useLayoutEffect(() => {
createSingleton();
}, [])The above can be observed https://codesandbox.io/s/damp-glade-r7xb2x?file=/src/index.js