[@types/react-redux] add types for hook factories (#39216)

* [@types/react-redux] add types for hook factories

* [@types/react-redux] add test of createSelectorHook+TypedUseSelectorHook

types/react-redux/index.d.ts

@@ -13,6 +13,7 @@
 //                 Boris Sergeyev <https://github.com/surgeboris>
 //                 Søren Bruus Frank <https://github.com/soerenbf>
 //                 Jonathan Ziller <https://github.com/mrwolfz>
+//                 Dylan Vann <https://github.com/dylanvann>
 // Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
 // TypeScript Version: 3.0
 
@@ -578,4 +579,28 @@ export interface TypedUseSelectorHook<TState> {
  */
 export function useStore<S = any, A extends Action = AnyAction>(): Store<S, A>;
 
+/**
+ * Hook factory, which creates a `useSelector` hook bound to a given context.
+ *
+ * @param Context passed to your `<Provider>`.
+ * @returns A `useSelector` hook bound to the specified context.
+ */
+export function createSelectorHook(context?: Context<ReactReduxContextValue>): typeof useSelector;
+
+/**
+ * Hook factory, which creates a `useStore` hook bound to a given context.
+ *
+ * @param Context passed to your `<Provider>`.
+ * @returns A `useStore` hook bound to the specified context.
+ */
+export function createStoreHook(context?: Context<ReactReduxContextValue>): typeof useStore;
+
+/**
+ * Hook factory, which creates a `useDispatch` hook bound to a given context.
+ *
+ * @param Context passed to your `<Provider>`.
+ * @returns A `useDispatch` hook bound to the specified context.
+ */
+export function createDispatchHook(context?: Context<ReactReduxContextValue>): typeof useDispatch;
+
 // tslint:enable:no-unnecessary-generics

types/react-redux/react-redux-tests.tsx

@@ -26,6 +26,9 @@ import {
     useDispatch,
     useSelector,
     useStore,
+    createDispatchHook,
+    createSelectorHook,
+    createStoreHook,
     TypedUseSelectorHook,
 } from 'react-redux';
 import objectAssign = require('object-assign');
@@ -1393,6 +1396,21 @@ function testUseStore() {
     typedState.things.stuff; // $ExpectError
 }
 
+// These should match the types of the hooks.
+function testCreateHookFunctions() {
+    // $ExpectType { <TDispatch = Dispatch<any>>(): TDispatch; <A extends Action<any> = AnyAction>(): Dispatch<A>; }
+    createDispatchHook();
+    // $ExpectType <TState, TSelected>(selector: (state: TState) => TSelected, equalityFn?: ((left: TSelected, right: TSelected) => boolean) | undefined) => TSelected
+    createSelectorHook();
+    interface RootState {
+        property: string;
+    }
+    // Should be able to create a version typed for a specific root state.
+    const useTypedSelector: TypedUseSelectorHook<RootState> = createSelectorHook();
+    // $ExpectType <S = any, A extends Action<any> = AnyAction>() => Store<S, A>
+    createStoreHook();
+}
+
 function testConnectedProps() {
     interface OwnProps {
         own: string;