client/js: When using Hardhat, fetchRuntimePublicKey falls through to fetchRuntimePublicKeyByChainId

[CedarMist]

There is a problem when using CI or a multi-container environment, for example Hardhat with the sapphire-dev where both are in containers on the same Docker network, where both containers have separate 172.16.x IP addresses.

The fetchRuntimePublicKey function isn't using the configured upstream JSON-RPC provider to request the call data public key. This means it's trying to access 127.0.0.1:8545 which won't work - because the sapphire-dev container is on another 172.x IP.

This is causing hardhat test to fail, but it works when running the tests locally, or when running the tests on the CI host rather than inside a container.

While this is annoying for CI, the more general problem is the provider detection code in fetchRuntimePublicKey doesn't seem to be functioning 100%.

---

One of the problems is there's duplicated logic to find the correct .send method inside fetchRuntimePublicKey because it's being called prior to wrapping the provider.

If it's moved until after the provider has been wrapped, then it can use the consistent EIP-1193 .request method.

sapphire-paratime/clients/js/src/compat.ts

Line 628 in 54ca5fc

export async function fetchRuntimePublicKey(

is called from

sapphire-paratime/clients/js/src/compat.ts

Line 265 in 54ca5fc

function getCipher(provider: UpstreamProvider): Cipher {

which is called from the top of the wrap function at:

sapphire-paratime/clients/js/src/compat.ts

Line 131 in 54ca5fc

const provider = new JsonRpcProvider(upstream);

and

sapphire-paratime/clients/js/src/compat.ts

Line 142 in 54ca5fc

const cipher = customCipher ?? getCipher(upstream);

---

Some notes on .send, if the provider isn't EIP-1193 compatible which has a standardized .request method. It will fall back to having to use .send which is wildly inconsistent across implementations.

• Ethers (v5 & v6) JSON-RPC provider = send(method:string,params[]) -> Promise
• Truffle = send(payload, callback) -> void

With .request it can be simplified as:

+    // EIP-1193 provider
+    if( 'request' in provider ) {
+      const {key} = await (provider as EIP1193Provider).request({method: OASIS_CALL_DATA_PUBLIC_KEY}) as {key:string};
+      if( key ) return arrayify(key);
+    }

Truffle HDWallet-provider: https://github.com/trufflesuite/truffle/blob/a6fb238ef954d3ad4c6fd4181b78ee3dc047c8bf/packages/hdwallet-provider/src/index.ts#L364-L368

public send(
    payload: JSONRPCRequestPayload,
    // @ts-ignore we patch this method so it doesn't conform to type
    callback: (error: null | Error, response: JSONRPCResponsePayload) => void
  ): void

EIP-1193: https://eips.ethereum.org/EIPS/eip-1193#appendix-i-consumer-facing-api-documentation

interface RequestArguments {
  readonly method: string;
  readonly params?: readonly unknown[] | object;
}

Provider.request(args: RequestArguments): Promise<unknown>;

Ethers JSON-RPC provider: https://github.com/ethers-io/ethers.js/blob/9197f9f938b5f3b5f97c043f2dab06854656c932/src.ts/providers/provider-jsonrpc.ts#L1139

async send(method: string, params: Array<any> | Record<string, any>): Promise<any> {

Web3 provider .send: https://docs.web3js.org/api/web3-providers-http/class/HttpProvider#send which notes the interface is deprecated and to use .request instead.

The big problem seems to be that neither Truffle nor Ethers support .request...

The isEthersSend function tries to determine between them:

sapphire-paratime/clients/js/src/compat.ts

Lines 248 to 263 in 54ca5fc

	function isEthersSend(
	send?: AsyncSend | JsonRpcProvider['send'],
	): send is JsonRpcProvider['send'] {
	if (!send) return false;
	// If the function is async, it's likely ethers send.
	try {
	const res = (send as any)(); // either rejects or calls back with an error
	if (res instanceof Promise) {
	res.catch(() => void {}); // handle the rejection before the next tick
	return true;
	}
	} catch {
	// This is prophyalictic. Neither kind of `send` should synchronously throw.
	}
	return false;
	}

And I used a bad hack to detect Truffle HDWallet provider:

sapphire-paratime/clients/js/src/compat.ts

Lines 648 to 655 in 54ca5fc

	const arg =
	'engine' in provider
	? // eslint-disable-next-line @typescript-eslint/no-unused-vars
	function (err: any, ok?: any) {
	return;
	}
	: [];
	const { key } = await source.send(OASIS_CALL_DATA_PUBLIC_KEY, arg);

But this needs cleaning up to make sure it's compatible with:

• Truffle
• Hardhat
• Metamask
• EIP-1193
• Ethers