- The example hook Counter.sol demonstrates the
beforeSwap()andafterSwap()hooks - The test template Counter.t.sol preconfigures the v4 pool manager, test tokens, and test liquidity.
Updating to v4-template:latest
This template is actively maintained -- you can update the v4 dependencies, scripts, and helpers:
git remote add template https://github.com/uniswapfoundation/v4-template
git fetch template
git merge template/main <BRANCH> --allow-unrelated-historiesrequires foundry
forge install
forge test
Other than writing unit tests (recommended!), you can only deploy & test hooks on anvil
# start anvil with TSTORE support
# (`foundryup`` to update if cancun is not an option)
anvil --hardfork cancun
# in a new terminal
forge script script/Anvil.s.sol \
--rpc-url http://localhost:8545 \
--private-key 0xac0974bec39a17e36ba4a6b4d238ff944bacb478cbed5efcae784d7bf4f2ff80 \
--broadcastNOTE: 11/21/2023, the Goerli deployment is out of sync with the latest v4. It is recommend to use local testing instead
For testing on Goerli Testnet the Uniswap Foundation team has deployed a slimmed down version of the V4 contract (due to current contract size limits) on the network.
The relevant addresses for testing on Goerli are the ones below
POOL_MANAGER = 0x0
POOL_MODIFY_POSITION_TEST = 0x0
SWAP_ROUTER = 0x0Update the following command with your own private key:
forge script script/00_Counter.s.sol \
--rpc-url https://rpc.ankr.com/eth_goerli \
--private-key [your_private_key_on_goerli_here] \
--broadcast
Because V4 is still in testing mode, most networks don't have liquidity pools live on V4 testnets. We recommend launching your own test tokens and expirementing with them that. We've included in the templace a Mock UNI and Mock USDC contract for easier testing. You can deploy the contracts and when you do you'll have 1 million mock tokens to test with for each contract. See deployment commands below
forge create script/mocks/mUNI.sol:MockUNI \
--rpc-url [your_rpc_url_here] \
--private-key [your_private_key_on_goerli_here]
forge create script/mocks/mUSDC.sol:MockUSDC \
--rpc-url [your_rpc_url_here] \
--private-key [your_private_key_on_goerli_here]
When installing dependencies with forge install, Github may throw a Permission Denied error
Typically caused by missing Github SSH keys, and can be resolved by following the steps here
Or adding the keys to your ssh-agent, if you have already uploaded SSH keys
Hook deployment failures are caused by incorrect flags or incorrect salt mining
- Verify the flags are in agreement:
getHookCalls()returns the correct flagsflagsprovided toHookMiner.find(...)
- Verify salt mining is correct:
- In forge test: the deployer for:
new Hook{salt: salt}(...)andHookMiner.find(deployer, ...)are the same. This will beaddress(this). If usingvm.prank, the deployer will be the pranking address - In forge script: the deployer must be the CREATE2 Proxy:
0x4e59b44847b379578588920cA78FbF26c0B4956C- If anvil does not have the CREATE2 deployer, your foundry may be out of date. You can update it with
foundryup
- If anvil does not have the CREATE2 deployer, your foundry may be out of date. You can update it with
- In forge test: the deployer for:
Additional resources:
v4-periphery contains advanced hook implementations that serve as a great reference
