types: Update Cache Interface types (#2554)

* update Cache.keys iterator type from string to Key

* revert lockfile

* use string as key for cache interface

* revert String coercion

_internal/types.ts

@@ -429,9 +429,9 @@ export type RevalidateCallback = <K extends RevalidateEvent>(
 
 export interface Cache<Data = any> {
  keys(): IterableIterator<string>
- get(key: Key): State<Data> | undefined
- set(key: Key, value: State<Data>): void
- delete(key: Key): void
+ get(key: string): State<Data> | undefined
+ set(key: string, value: State<Data>): void
+ delete(key: string): void
 }
 
 export interface StateDependencies {

_internal/utils/helper.ts

@@ -36,7 +36,7 @@ export const createCacheHelper = <Data = any, T = State<Data, any>>(
  const state = SWRGlobalState.get(cache) as GlobalState
  return [
  // Getter
- () => (cache.get(key) || EMPTY_CACHE) as T,
+ () => ((!isUndefined(key) && cache.get(key)) || EMPTY_CACHE) as T,
  // Setter
  (info: T) => {
  if (!isUndefined(key)) {
@@ -61,7 +61,7 @@ export const createCacheHelper = <Data = any, T = State<Data, any>>(
  }
 
  // If we haven't done any client-side updates, we return the current value.
- return (cache.get(key) || EMPTY_CACHE) as T
+ return ((!isUndefined(key) && cache.get(key)) || EMPTY_CACHE) as T
  }
  ] as const
 }