Uniswap v2 fork

This repository contains a fork of UniswapV2 contracts (core and periphery) using hardhat and hardhat-deploy.

First things to do after cloning is to install dependencies:

npm install

You need to create a .env file that match the hardhat.config.ts:

PRIVATE_KEY=<your-private-key>
SECOND_PRIVATE_KEY=<your-private-key>

SEPOLIA_RPC_URL=https://eth-sepolia.g.alchemy.com/v2/<your-api-key>
ETHERSCAN_API_KEY=<your-api-key>

MUMBAI_RPC_URL=https://polygon-mumbai.g.alchemy.com/v2/<your-api-key>
POLYGONSCAN_API_KEY=<your-api-key>

ETHERLINK_RPC_URL=https://node.ghostnet.etherlink.com
ETHERLINK_API_KEY=YOUCANCOPYME0000000000000000000000

NIGHTLY_RPC_URL=https://node.<deployment-date>.etherlink-nightly.tzalpha.net/
NIGHTLY_EXPLORER=https://explorer.<deployment-date>.etherlink-nightly.tzalpha.net/
NIGHTLY_CHAINID=<deployment-date>
NIGHTLY_PRIVATE_KEY=<nightly-private-key>

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0. Deploy Uniswap v2 protocol

Deploy factory (core)

You can then start by deploying the factory of UniswapV2 from the core:

npx hardhat deploy --tags UniswapV2Factory --network <your-network>

Important: you need to copy the code hash printed during the deployment. If you missed it, you can go on the explorer and in the read contract part, find the INIT_CODE_PAIR_HASH.

Deploy Router (periphery)

The first thing you need to do is to modify the hash in the library contracts/periphery/libraries/UniswapV2Library.sol line 24 with your own code hash from the deployment of your factory (without the 0x):

hex'96e8ac4277198ff8b6f785478aa9a39f403cb768dd02cbee326c3e7da348845f' // init code hash

Then you have two possibilities:

1. you want to deploy a new WETH contract with the router
2. you want to use an already deployd WETH contract

Deploy with a new WETH contract

You don't need to change anything in the code, just run the command:

npx hardhat deploy --tags UniswapV2Router02 --network <your-network>

Deploy without a new WETH contract

You need to remove "WETH9" the line 41 in the deploy/periphery/02-deploy-UniswapV2Router02.ts like so:

deployUniswapV2Router02.dependencies = ["UniswapV2Factory"]; // remove "WETH9" if you want to deploy the Router without deploying a WETH contract

Then you can specify the address of the WETH contract you want to use on the line 19 in the same file:

// const wethAddress = await (await ethers.getContract("WETH9")).getAddress();
const wethAddress = "weth_address";

You can finally run the command:

npx hardhat deploy --tags UniswapV2Router02 --network <your-network>

1. Set up the pair

You should have the protocol itself deployed. You now need to create a pair from the factory.

Here is the command to deploy 2 new ERC20 tokens and their pair on the Uniswap protocol:

npx hardhat deploy --tags UniswapV2Pair --network <your-network>

Note: if you want to use 2 existing tokens for the pair, you have to modify the deploy/core/02-deploy-UniswapV2Pair.ts script.

2., 3. and 4. Tests

If you want to launch the tests, you can run:

npx hardhat test test/periphery/UniswapV2Router02.ts --network <your-network>

Note: you can the launch each test individually by using the --grep flag and the name of the test after. Example:

npx hardhat test test/periphery/UniswapV2Router02.ts --network <your-network> --grep "addLiquidity"

NEW. Scenario create pair + add liquidity in one tx

Instead of setting up the pair, we will just deploy the tokens and then let the router with addLiquidity both deploys the pair and adds liquidity.

Note: Remember that you still have to deploy the factory and the router before you can use it!

Deploy the 2 tokens:

npx hardhat deploy --tags Tokens --network <your-network>

By default the test is disabled, you have to remove the 'x' in front of the test line 286 in test/periphery/UniswapV2Router02.ts.

Then you can run the script like so:

npx hardhat test test/periphery/UniswapV2Router02.ts --network <your-network> --grep "SPECIAL TEST"