Hardhat: Unlock any signer on mainnet forking

hardhat-unlock-signer.js

// MIT License
// Copyright (c) 2021 Dũng Trần a.k.a Chiro Hiro <chiro8x@gmail.com>

import { Signer } from '@ethersproject/abstract-signer'
import { Contract } from '@ethersproject/contracts'
import hre from 'hardhat'

interface IKeyValues {
  [key: string]: string
}

interface ISignerCache {
  [key: string]: Signer
}

const signers: ISignerCache = {}

const signerAlias: IKeyValues = {}

export async function unlockSigner(alias: string): Promise<Signer>

export async function unlockSigner(alias: string, address: string): Promise<Signer>

export async function unlockSigner(...params: string[]): Promise<Signer> {
  if (params.length === 1) {
    const [alias] = params
    if (typeof alias !== 'string') throw new Error('Alias was not a string')
    if (typeof signerAlias[alias] === 'undefined') throw new Error('Alias was not defined')
    if (typeof signers[signerAlias[alias]] === 'undefined') throw new Error('Signer was not unblocked')
    // We will get unlocked signer by alias
    return signers[signerAlias[alias]]
  } else if (params.length === 2) {
    const [alias, address] = params
    // Prevent case sensitive
    const key = address.toLowerCase()
    if (typeof signers[address] === 'undefined') {
      if (typeof signerAlias[alias] === 'undefined') {
        signerAlias[alias] = key
      }
      await hre.network.provider.request({
        method: 'hardhat_impersonateAccount',
        params: [address]
      })
      signers[address] = await hre.ethers.provider.getSigner(address)
    }
    return signers[address]
  }
  throw new Error('Number of parameters was not match')
}