Why TypeScript definition for cache object is not complete?

[ansavchenco]

Current TypeScript definition for cache object is the following:

export interface Cache<Data = any> {
    get(key: Key): Data | null | undefined;
    set(key: Key, value: Data): void;
    delete(key: Key): void;
}

The default cache object (when no provided specified) is however a regular js map with all the map methods on it. I sometimes need to use regular map methods like keys() and getting TypeScript complaining that there is no such method (even though there is) is very annoying.

So, is there a particular reason why Cache is typed this way and not as a regular map?

[koba04]

SWR uses Map as the default cache, but also provides a way to define a custom Cache, so the interface has only methods SWR needed.
In v2, SWR adds keys() to the interface, so you can use keys() without a TS error.