swapper-contract

A smart contract to swap any two ERC20 tokens

Setup

Install deps

yarn

Start a forked node

yarn hardhat node --fork https://<your-mainnet-rpc-url>

Create and fill the swap parameters in .env
```
cp .env.example .env
```

Deploy contract

yarn hardhat run scripts/deploy.js --network localhost

Export the deployed address of the contract or update in .env

export DEPLOYED_ADDRESS=0x9852795dbb01913439f534b4984fBf74aC8AfA12

Mint WETH9 tokens

yarn hardhat run scripts/mint.js --network localhost

Approve SwapRouter contract

yarn hardhat run scripts/approve.js --network localhost

Swap tokens

yarn hardhat run scripts/swap.js --network localhost

Testing

Start a forked node

yarn hardhat node --fork https://<your-mainnet-rpc-url>

Run hardhat tests

yarn hardhat test test/swapper.js --network localhost

Sample output:

yarn run v1.22.19
$ /home/dfqm8/work/plena/swapper-contract/node_modules/.bin/hardhat test test/swapper.js --network localhost


Swapper
    Single-hop Swaps: WETH9 -> USDC
    ✔ Should check signer to own some amount of WETH9
    ✔ Swap should fail without WETH9 approval (577ms)
    ✔ Contract should be approved
Swapping 0.01 WETH9 with USDC using deployed Swapper contract
WETH9 before swap: 50000000000000000000n
USDC before swap: 0n
WETH9 after swap: 49990000000000000000n
USDC after swap: 23434863n
    ✔ Should swap tokens post approval (5106ms)
    Multi-hop Swaps: USDC -> USDT
    ✔ Should check signer to own some amount of USDC
    ✔ Swap should fail without USDC approval (506ms)
    ✔ Contract should be approved
Swapping 10 USDC Tokens with USDT using deployed Swapper contract
USDC before swap: 23434863n
USDT before swap: 77916n
USDC after swap: 13434863n
USDT after swap: 10008926n
    ✔ Should swap USDC with USDT and via WETH9 (4819ms)


8 passing (13s)

Done in 13.88s.

dafaqdhruv/swapper-contract

swapper-contract

Setup

Testing