A simple way to generate query-hash for `apollo client:extract`

persistedLink.ts

import { defaultOperationRegistrySignature, operationHash } from 'apollo-graphql/lib/operationId'

const persistedLink = createPersistedQueryLink({
	generateHash: (document) => {
		const operationName = document.definitions.find(
			(definition) => definition.kind === 'OperationDefinition',
			// @ts-ignore
		)!.name.value
		const printed = defaultOperationRegistrySignature(document, operationName)
		return operationHash(printed)
	},
})

// Trade off:
// - Spend more cpu time 3-15 ms for creating hash. (depend on string length)
// - Additional Chunk size 40KB GZip. (by apollo-graphql package)
// Ref: https://github.com/apollographql/apollo-client/issues/7032

/*
// Note: If you are using V8 (e.g. cloudflare worker). You can replace `operationHash` with this custom function.

const toHex = (hashBuffer: ArrayBuffer) => {
	const hashArray = Array.from(new Uint8Array(hashBuffer))
	return hashArray.map((b) => `00${b.toString(16)}`.slice(-2)).join('')
}
const operationHash = async (message: string) => {
	const msgBuffer = new TextEncoder().encode(message)
	const hashBuffer = await crypto.subtle.digest('SHA-256', msgBuffer)
	const result = toHex(hashBuffer)
	return result
}
*/