Install Brownie & Ganache-CLI, if you haven't already.
Sign up for Infura and generate an API key. Store it in the WEB3_INFURA_PROJECT_ID
environment variable.
export WEB3_INFURA_PROJECT_ID=YourProjectID
ETHERSCAN_TOKEN
environment variable.export ETHERSCAN_TOKEN=YourApiToken
.env.example
ETHERSCAN_TOKEN
and WEB3_INFURA_PROJECT_ID
NOTE: If you set up a global environment variable, that will take precedencebrownie bake yearn-strategy
To deploy the demo Yearn Strategy in a development environment:
$ brownie console
>>> vault = Vault.at("0xBFa4D8AA6d8a379aBFe7793399D3DdaCC5bBECBB") # yvDAI (v0.2.2)
>>> token = Token.at("0x6b175474e89094c44da98b954eedeac495271d0f") # DAI
>>> gov = "ychad.eth" # ENS for Yearn Governance Multisig
Strategy.sol
contract.>>> strategy = Strategy.deploy(vault, {"from": accounts[0]})
Transaction sent: 0xc8a35b3ecbbed196a344ed6b5c7ee6f50faf9b7eee836044d1c7ffe10093ef45
Gas price: 0.0 gwei Gas limit: 6721975
Flashloan.constructor confirmed - Block: 9995378 Gas used: 796934 (11.86%)
Flashloan deployed at: 0x3194cBDC3dbcd3E11a07892e7bA5c3394048Cc87
# 1000 DAI debt limit, no rate limit, 50 bps strategist fee
>>> vault.addStrategy(strategy, Wei("1000 ether"), 2 ** 256 - 1, 50, {"from": gov})
Transaction sent: 0xa70b90eb9a9899e8f6e709c53a436976315b4279c4b6797d0a293e169f94d5b4
Gas price: 0.0 gwei Gas limit: 6721975
Transaction confirmed - Block: 9995379 Gas used: 21055 (0.31%)
>>> harvest_tx = strategy.harvest({"from": accounts[0]}) # perform as many time as desired...
contracts/Strategy.sol
is where you implement your own logic for your strategy. In particular:
Strategy.name()
.Strategy.adjustPosition()
.Strategy.prepareReturn()
.Strategy.liquidatePosition()
.Strategy.exitPosition()
.want
tokens managed by the strategy via Strategy.estimatedTotalAssets()
.Strategy.prepareMigration()
.Strategy.protectedTokens()
.To run the tests:
brownie test
The example tests provided in this mix start by deploying and approving your Strategy.sol
contract. This ensures that the loan executes succesfully without any custom logic. Once you have built your own logic, you should edit tests/test_flashloan.py
and remove this initial funding logic.
See the Brownie documentation for more detailed information on testing your project.
Use the --interactive
flag to open a console immediatly after each failing test:
brownie test --interactive
Within the console, transaction data is available in the history
container:
>>> history
[<Transaction '0x50f41e2a3c3f44e5d57ae294a8f872f7b97de0cb79b2a4f43cf9f2b6bac61fb4'>,
<Transaction '0xb05a87885790b579982983e7079d811c1e269b2c678d99ecb0a3a5104a666138'>]
Examine the TransactionReceipt
for the failed test to determine what went wrong. For example, to view a traceback:
>>> tx = history[-1]
>>> tx.traceback()
To view a tree map of how the transaction executed:
>>> tx.call_trace()
See the Brownie documentation for more detailed information on debugging failed transactions.
If you are using Ganache to fork a network, then you may have issues with the blockchain archive state every 30 minutes. This is due to your node provider (i.e. Infura) only allowing free users access to 30 minutes of archive state. To solve this, upgrade to a paid plan, or simply restart your ganache instance and redploy your contracts.