(persisted) - Add generateHash option to the persistedFetchExchange

[lorenries]

Summary

This PR adds support for a custom hash function in the persisted query exchange. This is useful for non-browser environments like react-native, where you might want to use a different crypto API (like Expo's, for instance).

Usage:

import sha256 from "my-library";

const client = createClient({
  url: 'http://localhost:1234/graphql',
  exchanges: [
    dedupExchange,
    cacheExchange,
    persistedFetchExchange({ generateHash: sha256 }),
    fetchExchange
  ],
});

Set of changes

Adds an argument to the persistedFetchExchange factory. No breaking changes.

[changeset-bot]

🦋 Changeset is good to go

Latest commit: 861cc51

We got this.

This PR includes changesets to release 1 package

Name	Type
@urql/exchange-persisted-fetch	Minor

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[JoviDeCroock]

This is looking great already, do you mind adding a changeset by doing yarn changeset at the root and indicating this as a minor version bump

[kitten]

Thanks for picking this up! We really haven’t had time to look into React Native support and different avenues, but seeing how simple this addition is it just makes more sense 👍

[kitten]

Thanks again! This has now been published as 1.1.0 https://github.com/FormidableLabs/urql/blob/main/exchanges/persisted-fetch/CHANGELOG.md#110

[lorenries]

Cool! Thank you both ❤️