cardano-graphql Provider

[rhyslbw]

1. Hoist the Provider to the core package

The prototype modelled the concept of remote wallets, and required the Provider to be typed as either Cardano or Wallet. We have de-scoped this to focus exclusively on client-side wallets, so the concept can be reduced to what is observed here:

cardano-js-sdk/prototype/src/Provider/CardanoProvider.ts

Lines 10 to 15 in 854cf42

	export interface CardanoProvider extends BaseProvider {
	submitTransaction: SubmitTransaction
	queryUtxosByAddress: QueryUtxosByAddress
	queryTransactionsByAddress: QueryTransactionsByAddress
	queryTransactionsById: QueryTransactionsById
	}

Align the Provider interface with the API defined by Ogmios, as this is a reflection of the Cardano model. i.e :

• submitTransaction -> submitTx
• queryUtxosByAddress -> utxo

Replace the types defined here with what can be imported by the @cardano-ogmios/client package:

cardano-js-sdk/prototype/src/Provider/CardanoProvider.ts

Lines 5 to 8 in 854cf42

	export type SubmitTransaction = (signedTransaction: string) => Promise<boolean>
	export type QueryUtxosByAddress = (addresses: string[]) => Promise<Utxo[]>
	export type QueryTransactionsByAddress = (addresses: string[]) => Promise<{ id: string, inputs: TransactionInput[], outputs: TransactionOutput[] }[]>
	export type QueryTransactionsById = (ids: string[]) => Promise<any[]>

We will add other methods in later tasks.

2. Create a new package called @cardano-sdk/cardano-graphql-provider

Create an implementation of the provider using @cardano-graphql/client-ts.
Here's a sample from the prototype:

cardano-js-sdk/prototype/src/lib/Providers/ClientHttpProvider.ts

Lines 1 to 11 in 854cf42

	import { CardanoProvider } from '../../Provider'
	export function ClientHttpProvider (_uri: string): CardanoProvider {
	// To be implemented by: https://github.com/input-output-hk/cardano-js-sdk/issues/4
	// This will likely convert this interface to interact with Jormangandr and remove the any
	// type casting
	return {
	submitTransaction: (_signedTransaction: string) => new Error('Not yet implemented'),
	queryUtxo: (_utxos: string[]) => new Error('Not yet implemented')
	} as any
	}

Use the public testnet for basic tests where applicable, selecting a random address using the explorer. It's acceptable to defer tests for the submitTx until we have covered this feature.