permissionless/utils/toOwner.ts

A utility library for working with ERC-4337

import {
    type Account,
    type Address,
    type Chain,
    type EIP1193Provider,
    type LocalAccount,
    type OneOf,
    type Transport,
    type WalletClient,
    createWalletClient,
    custom
} from "viem"
import { toAccount } from "viem/accounts"

import { signTypedData } from "viem/actions"
import { getAction } from "viem/utils"

export type EthereumProvider = OneOf<
    { request(...args: any): Promise<any> } | EIP1193Provider
>

export async function toOwner<provider extends EthereumProvider>({
    owner,
    address
}: {
    owner: OneOf<
        | provider
        | WalletClient<Transport, Chain | undefined, Account>
        | LocalAccount
    >
    address?: Address
}): Promise<LocalAccount> {
    if ("type" in owner && owner.type === "local") {
        return owner as LocalAccount
    }

    let walletClient:
        | WalletClient<Transport, Chain | undefined, Account>
        | undefined = undefined

    if ("request" in owner) {
        if (!address) {
            try {
                ;[address] = await (owner as EthereumProvider).request({
                    method: "eth_requestAccounts"
                })
            } catch {
                ;[address] = await (owner as EthereumProvider).request({
                    method: "eth_accounts"
                })
            }
        }
        if (!address) {
            // For TS to be happy
            throw new Error("address is required")
        }
        walletClient = createWalletClient({
            account: address,
            transport: custom(owner as EthereumProvider)
        })
    }

    if (!walletClient) {
        walletClient = owner as WalletClient<
            Transport,
            Chain | undefined,
            Account
        >
    }

    return toAccount({
        address: walletClient.account.address,
        async signMessage({ message }) {
            return walletClient.signMessage({ message })
        },
        async signTypedData(typedData) {
            return getAction(
                walletClient,
                signTypedData,
                "signTypedData"
            )(typedData as any)
        },
        async signTransaction(_) {
            throw new Error(
                "Smart account signer doesn't need to sign transactions"
            )
        }
    })
}