hardhat-deal

This plugin allows the developer to deal arbitrary amount of ERC20 tokens to any account on the hardhat network, to ease test development. The storage value of the mapping balanceOf is manipulated in order to manipulate the balance of the given user.

The plugin is shipped with a list of storage slots, which enable faster deals. Additionnally, the developer can provide a mapping of storage slots on custom ERC20s or edit the hardhat configuration on-the-fly (for example when deploying custom ERC20s during tests). If the ERC20 is not found in the configuration, the plugin automatically tries to brute-force the storage slot of the mapping balanceOf, and throws an error if it cannot.

Installation

npm install hardhat-deal

yarn add hardhat-deal

Import the plugin in your hardhat.config.js:

require("hardhat-deal");

Or if you are using TypeScript, in your hardhat.config.ts:

import "hardhat-deal";

Usage

Testing

import { deal } from "hardhat-deal";

const lusd = "0x5f98805A4E8be255a32880FDeC7F6728C6568bA0";
const user = "0x7Ef4174aFdF4514F556439fa2822212278151Db6";
const amount = "10000000000000000000"; // 10 LUSD

// Deal 10 LUSD to the user
await deal(lusd, user, amount);

// Optionnally provide a last parameter specifying how far to brute-force the storage slot (default: 12)
await deal(lusd, user, amount, 15);

Standalone task

This plugin also provides a task deal that can be called with hardhat to deal ERC20 tokens on a separate hardhat node:

npx hardhat deal <recipient> <ERC20 symbol or address> <amount> --network localhost

For example:

npx hardhat deal <recipient> WETH 2000000000000000000 --network localhost

Run npx hardhat deal --help to see the list of supported ERC20 symbols.

Configuration

This plugin extends HardhatUserConfig object with an optional dealSlots field, allowing one to customize the default storage slots used to deal ERC20 tokens, for faster usage (because the plugin no longer needs to brute-force the ERC20 storage slot).

This is an example of how to set it:

module.exports = {
  networks: {
    // If using an external network, you can optionnally provide a custom rpc endpoint to manipulate the network's storage.
    tenderly: {
      rpcEndpoints: {
        setStorageAt: "tenderly_setStorageAt",
      },
    },
  },
  dealSlots: {
    "0x5f98805A4E8be255a32880FDeC7F6728C6568bA0": 2, // LUSD
  },
};