Convex frxETH/WETH strategy

[naddison36]

This implementation of the Convex frxETH/WETH strategy uses Curve solidity libraries to abstract whether the Curve pool has two or three coins.

The other implementation clones BaseCurveStrategy to BaseTwoAssetCurveStrategy and ConvexStrategy to ConvexTwoAssetStrategy. #1842

Changes Summary

• Removed unused imports from the Harvester contracts
• I've moved the curve mocks into a mocks/curve folder
• Curve pool and gauge mocks now burn the LP token on remove liquidity instead of transferring it back to the pool
• Added calc_token_amount and fee functions to the abstract Curve Metapool. Also added remove_liquidity_imbalance with receiver override.
• Changes to other strategies to fit strategy behaviour
  • Aave - added Withdrawal event to withdrawAll
  • Compound - added Withdrawal event to withdrawAll
  • Generalized 4626 - only emit Withdrawal event if there was a withdraw amount in withdrawAll
• OSUD AMO and 3Pool strategies updated to new BaseConvexStrategy
• Moved Curve interfaces in the strategies folder into a curve subfolder
• Add new Curve pool libraries that abstract the number of coins in a pool
• deployWithConfirmation in utils/deploy.js now supports linked libraries
• Moved replaceContractAt and hardhatSetBalance from utils/deploy.js to utils/hardhat.js
• Added reusable unit tests for governable, harvester and strategy behaviours
• Added ConvexFrxEthWethStrategyProxy that delegates to ConvexStrategy and is linked to the CurveTwoCoinLib library
• Added 078_convex_frax_strategy deploy script for the new Convex strategy that uses the frxETH/WETH Curve pool

Design decisions

https://www.notion.so/originprotocol/Design-of-frxETH-WETH-Strategy-7cf0ddf4f14746a2a433b15cd7aa67a5

Contracts

The new strategy is in green

Value Flow

Tests

Unit tests

yarn test ./test/strategies/convexFrxEthWeth.js

Fork tests

yarn test:fork ./test/strategies/convex-frxeth.fork-test.js

Deploy

The contracts/deploy/078_convex_frax_strategy.js script will deploy the new strategy and propose the required governance acrtions.

Review

If you made a contract change, make sure to complete the checklist below before merging it in master.

Refer to our documentation for more details about contract security best practices.

Contract change checklist:

• Code reviewed by 2 reviewers.
• Copy & paste code review security checklist below this checklist.
• Unit tests pass
• Slither tests pass with no warning
• Echidna tests pass if PR includes changes to OUSD contract (not automated, run manually on local)

[github-actions]

	Warnings
⚠️	👀 This PR needs at least 2 reviewers

Generated by 🚫 dangerJS against f98accd