add comparison of data via compare config

[darrenjennings]

swr uses a compare function to detect changes to see if the cache needs to be updated. Would be a nice addition before setting the cache. vercel/swr#219

[bikingbadger]

Trying to get involved in open source and would like to tackle this one. Might just need to pick your brain a bit to exactly understand what you mean. From what I understand you want the same functionality of using compare in swrv as it is in swr?

[darrenjennings]

@bikingbadger yes we are looking to have some parity re: vercel/swr#655

1. yarn add dequal
2. add compare as a function to the config https://github.com/Kong/swrv/blob/master/src/use-swrv.ts#L43 with the default of import { dequal } from 'dequal/lite
3. compare the values in the cache before setting the data here: https://github.com/Kong/swrv/blob/master/src/use-swrv.ts#L234
4. add a test should allow use custom isEqual method similar to: https://github.com/vercel/swr/blame/a9c10f74963bbe3b566201ef9f43a2242440f0f1/test/use-swr-refresh.test.tsx#L250

[bikingbadger]

Great. Thanks for the run down. I will start taking a look at it and working on a solution. Appreciate the help @darrenjennings