hardhat-swapper-util-ts

recompiles various UniswapV2 contracts.

Note: this differs from the existing hardhat-plugin-deploy-v3 in that it completely recompiles the Uniswap V2 contracts. As the Uniswap periphery library depends on a hash of the V2Pair contract, I have also build a package to compensate for the hardcoded hash (link).

Installation

1. Install: npm install --save-dev @jgensler8_2/hardhat-swapper-util-ts .

• Note: this has several common peer dependencies and might cause errors if you already have those as devDependencies.

2. Install contract dependencies: npx hardhat run install-deps .

• Note: rather than overriding hardhats internal build chain, hardhad-swapper-utils-ts installs contracts to allow native import to build the correct dependency tree.

3. Update your hardhat config:

// file: hardhat.config.js

// 3.1 import 
const swapper_utils = require('@jgensler8_2/hardhat-swapper-utils-ts');

{
// 3.2: uniswap depends on older version of compilers, use ones exposed by this package
  solidity: {
    compilers: [
      ...swapper_utils.compilers
    ],
  },
// 3.3: recompiling uniswap leads to larger bytecode
  networks: {
    hardhat: {
      allowUnlimitedContractSize: true,
    }
  },
}

4. Access Swapper utils via HRE:

// file: your-script.js

const hre = require("hardhat");

async function main() {
    let su = hre.su
    let state = su.defaultState()
    // deploy all at once
    state = await su.autoDeployAll(state)
    /*
    // or deploy manually
    state = await su.autoDeployTokens(state)
    state = await su.autoDeployUniswapV2Factory(state)
    state = await su.autoDeployUniswapV2Pairs(state)
    state = await su.autoDeployUniswapV2Router(state)
    state = await su.autoDripAndInitializePools(state)
    */

    const amountAIn = 10000
    const tokenA = state.tokens["TOKA"]
    const tokenB = state.tokens["TOKB"]
    let amounts = await state.uniswapV2Router02.getAmountsOut(amountAIn, [tokenA.address, tokenB.address])

    console.log(`amounts: ${amounts}`)
}

main()
    .then(() => process.exit(0))
    .catch(error => {
        console.error(error);
        process.exit(1);
    });

5. Finally, run your script:

$ npx hardhat run your-script.js
amounts: 10000,906

Testing

Running npm run test will run every test located in the test/ folder. They use mocha and chai, but you can customize them.

Linting and autoformat

All of Hardhat projects use prettier and tslint.

You can check if your code style is correct by running npm run lint, and fix it with npm run lint:fix.

Building the project

Just run npm run build ️👷