Flip unstable_useTransition array params + edit eslint test

types/react/experimental.d.ts

@@ -142,16 +142,16 @@ declare module '.' {
      *
      * The `useTransition` hook returns two values in an array.
      *
-     * The first is a function that takes a callback. We can use it to tell React which state we want to defer.
-     * The seconda boolean. It’s React’s way of informing us whether we’re waiting for the transition to finish.
+     * The first is boolean, React’s way of informing us whether we’re waiting for the transition to finish.
+     * The seconda is a function that takes a callback. We can use it to tell React which state we want to defer.
      *
      * **If some state update causes a component to suspend, that state update should be wrapped in a transition.**
      *
      * @param config An optional object with `timeoutMs`
      *
      * @see https://reactjs.org/docs/concurrent-mode-reference.html#usetransition
      */
-    export function unstable_useTransition(): [TransitionStartFunction, boolean];
+    export function unstable_useTransition(): [boolean, TransitionStartFunction];
 
     const opaqueIdentifierBranding: unique symbol;
     /**

types/react/test/experimental.tsx

@@ -5,7 +5,7 @@ import React = require('react');
 function useExperimentalHooks() {
     const [toggle, setToggle] = React.useState(false);
 
-    const [startTransition, done] = React.unstable_useTransition();
+    const [done, startTransition] = React.unstable_useTransition();
     // $ExpectType boolean
     done;