Support asynchronous methods in ICacheStore

[therealsujitk]

It would be great if asynchronous methods were supported in ICacheStore for when developers need to implement custom caching that cannot be called synchronously.

• Original issue - spotify/spotify-web-api-ts-sdk#114
• Pull Request - spotify/spotify-web-api-ts-sdk#115

@fostertheweb it would be great if you could review & test this PR and merge it to this fork if you think everything looks good. Thanks!

[fostertheweb]

Sorry, I need to figure out my GitHub notifications. Could we avoid making this many changes by adding an IAsyncCacheStore?

export interface IAsyncCacheStore {
  get(key: string): Promise<string | null>;
  set(key: string, value: string): Promise<void>;
  remove(key: string): Promise<void>;
}

[therealsujitk]

@fostertheweb we could create a separate IAsyncCacheStore instead of modifying the current one, but it would be pointless to be honest. The rest of the changes will have to remain the same since they still have to be awaited.

Since I made the functions in ICacheStore asynchronous, we need to await all the function calls to this, and some of those function calls weren't in async functions itself, so they had to be made asynchronous as well and so on.

If we create a separate IAsyncCacheStore, we'll need to make even more changes so typescript knows that the cache store can be either ICacheStore or IAsyncCacheStore. I feel the current modification is better as it also supports the current synchronous cache store and doesn't include any breaking changes (except maybe the asynchronous logout function as mentioned in the third point under Changes).

[fostertheweb]

Ah yeah for whatever reason I was thinking you created a fully custom caching strategy, instead of extending GenericCache. This makes sense, I'll copy the PR over here.

[fostertheweb]

Solved with #18

[fostertheweb]

@therealsujitk Version 1.3.0 published to npm

[therealsujitk]

@fostertheweb Thankyou!