Router: Use a single RouterContext (#9792)

packages/router/src/router-context.tsx

@@ -1,4 +1,4 @@
-import React, { useReducer, createContext, useContext } from 'react'
+import React, { createContext, useContext, useMemo } from 'react'
 
 import type { AuthContextInterface } from '@redwoodjs/auth'
 import { useNoAuth } from '@redwoodjs/auth'
@@ -27,46 +27,28 @@ export interface RouterState {
 
 const RouterStateContext = createContext<RouterState | undefined>(undefined)
 
-export interface RouterSetContextProps {
-  setState: (newState: Partial<RouterState>) => void
-}
-
-const RouterSetContext = createContext<
-  React.Dispatch<Partial<RouterState>> | undefined
->(undefined)
-
-/***
- *
- * This file splits the context into getter and setter contexts.
- * This was originally meant to optimize the number of redraws
- * See https://kentcdodds.com/blog/how-to-optimize-your-context-value
- *
- */
 export interface RouterContextProviderProps
   extends Omit<RouterState, 'useAuth'> {
   useAuth?: UseAuth
   children: React.ReactNode
 }
 
-function stateReducer(state: RouterState, newState: Partial<RouterState>) {
-  return { ...state, ...newState }
-}
-
 export const RouterContextProvider: React.FC<RouterContextProviderProps> = ({
   useAuth,
   paramTypes,
   children,
 }) => {
-  const [state, setState] = useReducer(stateReducer, {
-    useAuth: useAuth || useNoAuth,
-    paramTypes,
-  })
+  const state = useMemo(
+    () => ({
+      useAuth: useAuth || useNoAuth,
+      paramTypes,
+    }),
+    [useAuth, paramTypes]
+  )
 
   return (
     <RouterStateContext.Provider value={state}>
-      <RouterSetContext.Provider value={setState}>
-        {children}
-      </RouterSetContext.Provider>
+      {children}
     </RouterStateContext.Provider>
   )
 }