Function useState

packages/react-reconciler/src/ReactFiberHooks.js:4096–4108

(
      initialState: (() => S) | S,
    )

      return mountRef(initialValue);
    },
    useState<S>(
      initialState: (() => S) | S,
    ): [S, Dispatch<BasicStateAction<S>>] {
      currentHookNameInDev = 'useState';
      mountHookTypesDev();
      const prevDispatcher = ReactSharedInternals.H;
      ReactSharedInternals.H = InvalidNestedHooksDispatcherOnMountInDEV;
      try {
        return mountState(initialState);
      } finally {
        ReactSharedInternals.H = prevDispatcher;
      }
    },
    useDebugValue<T>(value: T, formatterFn: ?(value: T) => mixed): void {
      currentHookNameInDev = 'useDebugValue';
      mountHookTypesDev();