Readable streams can be passed to opts.fileCache

[sebdeckers]

Allows stream.Readable instances in fileCache. Duck-typing the stream so other allowed types (String/Buffer) will not be affected.

Seemed like there is no provided way to persist the cache. I'm using a Proxy's getOwnPropertyDescriptor trap (triggered by xhas) to dynamically populate the cache with asynchronous fs.readFile calls.

Would otherwise suggest having an asynchronous fileRead API with a cache lookup callback in the options.

[goto-bus-stop]

I think this need is addressed by the persistentCache option that was added in #124?