hardhat.config.js

require('@nomicfoundation/hardhat-toolbox');
require('hardhat-preprocessor');
const fs = require('fs');

function getRemappings() {
  return fs
    .readFileSync('remappings.txt', 'utf8')
    .split('\n')
    .filter(Boolean) // remove empty lines
    .filter((line) => !line.includes('node_modules')) // remove node_modules remappings
    .map((line) => line.trim().split('='));
}

/** @type import('hardhat/config').HardhatUserConfig */
module.exports = {
  solidity: {
    version: '0.8.20',
    settings: {
      optimizer: {
        enabled: true,
        runs: 200,
      },
    }
  },
  preprocess: {
    eachLine: (hre) => ({
      transform: (line) => {
        if (line.match(/^\s*import /i)) {
          for (const [from, to] of getRemappings()) {
            if (line.includes(from)) {
              line = line.replace(from, to);
              break;
            }
          }
        }
        return line;
      },
    }),
  },
  paths: {
    sources: './contracts',
    cache: './cache_hardhat',
    tests: './test/hardhat',
  },
};