refactor createCache

Author: shuding

src/cache.ts

@@ -1,45 +1,24 @@
 import { serialize } from './libs/serialize'
-import {
-  Cache as CacheType,
-  Key,
-  Provider,
-  Mutator,
-  ScopedMutator
-} from './types'
+import { Cache, Key } from './types'
 
-// The factory that binds the `mutate` function to the specific cache object.
-export function getCacheFactory(internalMutate: any) {
-  return function createCache<Data>(
-    provider: Provider
-  ): {
-    cache: CacheType
-    mutate: ScopedMutator<Data>
-  } {
-    function cacheSet(key: Key, value: any) {
-      const _key = typeof key === 'string' ? key : serialize(key)[0]
-      provider.set(_key, value)
-    }
-
-    function cacheDelete(key: Key) {
-      const [_key] = serialize(key)
-      provider.delete(_key)
-    }
+export function wrapCache(provider: Cache): Cache {
+  function cacheSet(key: Key, value: any) {
+    const _key = typeof key === 'string' ? key : serialize(key)[0]
+    provider.set(_key, value)
+  }
 
-    function cacheGet(key: Key): any {
-      return provider.get(key)
-    }
+  function cacheDelete(key: Key) {
+    const [_key] = serialize(key)
+    provider.delete(_key)
+  }
 
-    const cache = {
-      set: cacheSet,
-      get: cacheGet,
-      delete: cacheDelete
-    }
+  function cacheGet(key: Key): any {
+    return provider.get(key)
+  }
 
-    return {
-      cache,
-      mutate: (internalMutate as Mutator<Data>).bind(null, cache)
-    }
+  return {
+    set: cacheSet,
+    get: cacheGet,
+    delete: cacheDelete
   }
 }
-
-export const defaultCache = getCacheFactory(() => {})(new Map()).cache

src/config.ts

@@ -1,6 +1,6 @@
 import { dequal } from 'dequal/lite'
 
-import { defaultCache } from './cache'
+import { wrapCache } from './cache'
 import webPreset from './libs/web-preset'
 import { Configuration, RevalidatorOptions, Revalidator } from './types'
 
@@ -68,7 +68,7 @@ const defaultConfig = {
   fetcher,
 
   isPaused: () => false,
-  cache: defaultCache
+  cache: wrapCache(new Map())
 } as const
 
 export default defaultConfig

src/types.ts

@@ -214,9 +214,3 @@ export interface Cache {
   set(key: Key, value: any): any
   delete(key: Key): void
 }
-
-export interface Provider {
-  get(key: Key): any
-  set(key: Key, value: any): any
-  delete(key: Key): void
-}

src/use-swr.ts

@@ -3,7 +3,7 @@ import { useCallback, useRef, useDebugValue } from 'react'
 
 import defaultConfig from './config'
 import webPreset from './libs/web-preset'
-import { getCacheFactory } from './cache'
+import { wrapCache } from './cache'
 import { IS_SERVER, rAF, useIsomorphicLayoutEffect } from './env'
 import { serialize } from './libs/serialize'
 import SWRConfigContext from './config-context'
@@ -19,7 +19,8 @@ import {
   RevalidatorOptions,
   Updater,
   SWRConfiguration,
-  Cache
+  Cache,
+  ScopedMutator
 } from './types'
 
 type Revalidator = (...args: any[]) => void
@@ -681,6 +682,21 @@ Object.defineProperty(SWRConfigContext.Provider, 'default', {
 export const SWRConfig = SWRConfigContext.Provider as typeof SWRConfigContext.Provider & {
   default: SWRConfiguration
 }
-export const mutate = internalMutate.bind(null, defaultConfig.cache)
-export const createCache = getCacheFactory(internalMutate)
+export const mutate = internalMutate.bind(
+  null,
+  defaultConfig.cache
+) as ScopedMutator<any>
+export function createCache<Data>(
+  provider: Cache
+): {
+  cache: Cache
+  mutate: ScopedMutator<Data>
+} {
+  const cache = wrapCache(provider)
+  return {
+    cache,
+    mutate: internalMutate.bind(null, cache) as ScopedMutator<Data>
+  }
+}
+
 export default useSWR