refactor: use SWRGlobalState to store preloading requests

_internal/types.ts

@@ -5,6 +5,7 @@ export type GlobalState = [
   Record<string, RevalidateCallback[]>, // EVENT_REVALIDATORS
   Record<string, [number, number]>, // MUTATION: [ts, end_ts]
   Record<string, [any, number]>, // FETCH: [data, ts]
+  Record<string, FetcherResponse<any>>, // PRELOAD
   ScopedMutator, // Mutator
   (key: string, value: any, prev: any) => void, // Setter
   (key: string, callback: (current: any, prev: any) => void) => () => void // Subscriber

_internal/utils/cache.ts

@@ -79,6 +79,7 @@ export const initCache = <Data = any>(
           EVENT_REVALIDATORS,
           {},
           {},
+          {},
           mutate,
           setter,
           subscribe
@@ -132,5 +133,5 @@ export const initCache = <Data = any>(
     return [provider, mutate, initProvider, unmount]
   }
 
-  return [provider, (SWRGlobalState.get(provider) as GlobalState)[3]]
+  return [provider, (SWRGlobalState.get(provider) as GlobalState)[4]]
 }

_internal/utils/helper.ts

@@ -36,9 +36,9 @@ export const createCacheHelper = <Data = any, T = State<Data, any>>(
     // Setter
     (info: T) => {
       const prev = cache.get(key)
-      state[4](key as string, mergeObjects(prev, info), prev || EMPTY_CACHE)
+      state[5](key as string, mergeObjects(prev, info), prev || EMPTY_CACHE)
     },
     // Subscriber
-    state[5]
+    state[6]
   ] as const
 }

_internal/utils/preload.ts

@@ -1,12 +1,13 @@
-import { Middleware, Key, BareFetcher, FetcherResponse } from '../types'
+import { Middleware, Key, BareFetcher, GlobalState } from '../types'
 import { serialize } from './serialize'
-
-const REQUEST = new Map<string, FetcherResponse<any>>()
+import { cache } from './config'
+import { SWRGlobalState } from './global-state'
 
 export const preload = <Data = any>(key_: Key, fetcher: BareFetcher<Data>) => {
   const req = fetcher(key_)
   const key = serialize(key_)[0]
-  REQUEST.set(key, req)
+  const [, , , PRELOAD] = SWRGlobalState.get(cache) as GlobalState
+  PRELOAD[key] = req
   return req
 }
 
@@ -17,9 +18,10 @@ export const middleware: Middleware =
       fetcher_ &&
       ((...args: any[]) => {
         const key = serialize(key_)[0]
-        const req = REQUEST.get(key)
+        const [, , , PRELOAD] = SWRGlobalState.get(cache) as GlobalState
+        const req = PRELOAD[key]
         if (req) {
-          REQUEST.delete(key)
+          delete PRELOAD[key]
           return req
         }
         return fetcher_(...args)