@nomicfoundation/hardhat-ethers/src/internal/signers/signers.ts

Hardhat plugin for ethers

import type { HardhatEthersSigner as HardhatEthersSignerI } from "../../types.js";
import type { HardhatEthersProvider } from "../hardhat-ethers-provider/hardhat-ethers-provider.js";
import type {
  BlockTag,
  TransactionRequest,
  ethers,
  AuthorizationRequest,
  Authorization,
} from "ethers";
import type {
  EdrNetworkAccountsConfig,
  HttpNetworkAccountsConfig,
  NetworkConfig,
} from "hardhat/types/config";

import { HardhatError } from "@nomicfoundation/hardhat-errors";
import {
  assertArgument,
  computeAddress,
  getAddress,
  hexlify,
  resolveAddress,
  toUtf8Bytes,
  TypedDataEncoder,
  Wallet,
} from "ethers";

import { getRpcTransaction } from "../ethers-utils/ethers-utils.js";

import { deepCopy } from "./deep-copy.js";
import { derivePrivateKeys } from "./derive-private-key.js";
import { populate } from "./populate.js";

type SignerAccounts =
  | {
      type: "http";
      accounts: HttpNetworkAccountsConfig;
    }
  | {
      type: "edr-simulated";
      accounts: EdrNetworkAccountsConfig;
    };

export class HardhatEthersSigner implements HardhatEthersSignerI {
  readonly #gasLimit: bigint | undefined;
  readonly #signerAccounts: SignerAccounts;
  #cachedPrivateKey: string | undefined;

  public readonly address: string;
  public readonly provider: ethers.JsonRpcProvider | HardhatEthersProvider;
  public static networkName: string;
  public static networkConfig: NetworkConfig;

  public static async create(
    provider: HardhatEthersProvider,
    networkName: string,
    networkConfig: NetworkConfig,
    address: string,
  ): Promise<HardhatEthersSigner> {
    this.networkName = networkName;
    this.networkConfig = networkConfig;

    let gasLimit: bigint | undefined;

    if (networkConfig.gas !== "auto") {
      gasLimit = networkConfig.gas;
    }

    const signerAccounts: SignerAccounts =
      networkConfig.type === "http"
        ? { type: "http", accounts: networkConfig.accounts }
        : { type: "edr-simulated", accounts: networkConfig.accounts };

    return new HardhatEthersSigner(address, provider, signerAccounts, gasLimit);
  }

  private constructor(
    address: string,
    provider: ethers.JsonRpcProvider | HardhatEthersProvider,
    signerAccounts: SignerAccounts,
    gasLimit?: bigint | undefined,
  ) {
    this.address = getAddress(address);
    this.provider = provider;
    this.#gasLimit = gasLimit;

    this.#signerAccounts = signerAccounts;
  }

  public connect(
    provider: ethers.JsonRpcProvider | HardhatEthersProvider,
  ): ethers.Signer {
    return new HardhatEthersSigner(
      this.address,
      provider,
      this.#signerAccounts,
      this.#gasLimit,
    );
  }

  public async authorize(auth: AuthorizationRequest): Promise<Authorization> {
    const privateKey = await this.#getPrivateKey();

    if (privateKey === undefined) {
      throw new HardhatError(
        HardhatError.ERRORS.HARDHAT_ETHERS.GENERAL.NO_PRIVATE_KEY_FOR_ADDRESS,
        {
          address: this.address,
        },
      );
    }

    const wallet = new Wallet(privateKey, this.provider);

    return wallet.authorize(auth);
  }

  public async populateAuthorization(
    _auth: AuthorizationRequest,
  ): Promise<AuthorizationRequest> {
    const auth = { ..._auth };

    // Add a chain ID if not explicitly set to 0
    if (auth.chainId === null || auth.chainId === undefined) {
      auth.chainId = (await this.provider.getNetwork()).chainId;
    }

    if (auth.nonce === null || auth.nonce === undefined) {
      auth.nonce = await this.getNonce();
    }

    return auth;
  }

  public getNonce(blockTag?: BlockTag | undefined): Promise<number> {
    return this.provider.getTransactionCount(this.address, blockTag);
  }

  public populateCall(
    tx: TransactionRequest,
  ): Promise<ethers.TransactionLike<string>> {
    return populate(this, tx);
  }

  public populateTransaction(
    tx: TransactionRequest,
  ): Promise<ethers.TransactionLike<string>> {
    return this.populateCall(tx);
  }

  public async estimateGas(tx: TransactionRequest): Promise<bigint> {
    return this.provider.estimateGas(await this.populateCall(tx));
  }

  public async call(tx: TransactionRequest): Promise<string> {
    return this.provider.call(await this.populateCall(tx));
  }

  public resolveName(name: string): Promise<string | null> {
    return this.provider.resolveName(name);
  }

  public async signTransaction(_tx: TransactionRequest): Promise<string> {
    // TODO if we split the signer for the in-process and json-rpc networks,
    // we can enable this method when using the in-process network or when the
    // json-rpc network has a private key
    throw new HardhatError(
      HardhatError.ERRORS.HARDHAT_ETHERS.GENERAL.METHOD_NOT_IMPLEMENTED,
      {
        method: "HardhatEthersSigner.signTransaction",
      },
    );
  }

  public async sendTransaction(
    tx: TransactionRequest,
  ): Promise<ethers.TransactionResponse> {
    // This cannot be mined any earlier than any recent block

    const blockNumber = await this.provider.getBlockNumber();

    // Send the transaction
    const hash = await this.#sendUncheckedTransaction(tx);

    // Unfortunately, JSON-RPC only provides and opaque transaction hash
    // for a response, and we need the actual transaction, so we poll
    // for it; it should show up very quickly

    return new Promise((resolve) => {
      const timeouts = [1000, 100];
      const checkTx = async () => {
        // Try getting the transaction
        const txPolled = await this.provider.getTransaction(hash);
        if (txPolled !== null) {
          resolve(txPolled.replaceableTransaction(blockNumber));
          return;
        }

        // Wait another 4 seconds
        setTimeout(() => {
          // eslint-disable-next-line @typescript-eslint/no-floating-promises -- this check must be done in an async way
          checkTx();
        }, timeouts.pop() ?? 4000);
      };

      // eslint-disable-next-line @typescript-eslint/no-floating-promises -- this check must be done in an async way
      checkTx();
    });
  }

  public signMessage(message: string | Uint8Array): Promise<string> {
    const resolvedMessage =
      typeof message === "string" ? toUtf8Bytes(message) : message;
    return this.provider.send("personal_sign", [
      hexlify(resolvedMessage),
      this.address.toLowerCase(),
    ]);
  }

  public async signTypedData(
    domain: ethers.TypedDataDomain,
    types: Record<string, ethers.TypedDataField[]>,
    value: Record<string, any>,
  ): Promise<string> {
    const copiedValue = await deepCopy(value);

    // Populate any ENS names (in-place)
    const populated = await TypedDataEncoder.resolveNames(
      domain,
      types,
      copiedValue,
      async (v: string) => {
        return v;
      },
    );

    return this.provider.send("eth_signTypedData_v4", [
      this.address.toLowerCase(),
      JSON.stringify(
        TypedDataEncoder.getPayload(populated.domain, types, populated.value),
        (_k, v) => {
          if (typeof v === "bigint") {
            return v.toString();
          }

          return v;
        },
      ),
    ]);
  }

  public async getAddress(): Promise<string> {
    return this.address;
  }

  public toJSON() {
    return `<SignerWithAddress ${this.address}>`;
  }

  async #sendUncheckedTransaction(tx: TransactionRequest): Promise<string> {
    const resolvedTx = await deepCopy(tx);

    const promises: Array<Promise<void>> = [];

    // Make sure the from matches the sender
    if (resolvedTx.from !== null && resolvedTx.from !== undefined) {
      const _from = resolvedTx.from;
      promises.push(
        (async () => {
          const from = await resolveAddress(_from, this.provider);
          assertArgument(
            from !== null &&
              from !== undefined &&
              from.toLowerCase() === this.address.toLowerCase(),
            "from address mismatch",
            "transaction",
            tx,
          );
          resolvedTx.from = from;
        })(),
      );
    } else {
      resolvedTx.from = this.address;
    }

    if (resolvedTx.gasLimit === null || resolvedTx.gasLimit === undefined) {
      if (this.#gasLimit !== undefined) {
        resolvedTx.gasLimit = this.#gasLimit;
      } else {
        promises.push(
          (async () => {
            resolvedTx.gasLimit = await this.provider.estimateGas({
              ...resolvedTx,
              from: this.address,
            });
          })(),
        );
      }
    }

    // The address may be an ENS name or Addressable
    if (resolvedTx.to !== null && resolvedTx.to !== undefined) {
      const _to = resolvedTx.to;
      promises.push(
        (async () => {
          resolvedTx.to = await resolveAddress(_to, this.provider);
        })(),
      );
    }

    // Wait until all of our properties are filled in
    if (promises.length > 0) {
      await Promise.all(promises);
    }

    const hexTx = getRpcTransaction(resolvedTx);

    return this.provider.send("eth_sendTransaction", [hexTx]);
  }

  async #getPrivateKey(): Promise<string | undefined> {
    if (this.#cachedPrivateKey === undefined) {
      const privateKeys = await this.#getPrivateKeys();

      this.#cachedPrivateKey = privateKeys.find(
        (key) => computeAddress(key) === this.address,
      );
    }

    return this.#cachedPrivateKey;
  }

  async #getPrivateKeys(): Promise<string[]> {
    const { type, accounts } = this.#signerAccounts;

    if (type === "http") {
      if (accounts === "remote") {
        throw new HardhatError(
          HardhatError.ERRORS.HARDHAT_ETHERS.GENERAL.ACCOUNTS_OF_TYPE_REMOTE,
        );
      }

      if (Array.isArray(accounts)) {
        return Promise.all(accounts.map((acc) => acc.get()));
      }

      if ("mnemonic" in accounts) {
        return derivePrivateKeys(accounts);
      }
    }

    if (type === "edr-simulated") {
      if (Array.isArray(accounts)) {
        return Promise.all(accounts.map((acc) => acc.privateKey.get()));
      }

      if ("mnemonic" in accounts) {
        return derivePrivateKeys(accounts);
      }
    }

    throw new HardhatError(
      HardhatError.ERRORS.HARDHAT_ETHERS.GENERAL.WRONG_ACCOUNTS_FORMAT,
    );
  }
}

// exported as an alias to make migration easier
export { HardhatEthersSigner as SignerWithAddress };