YearnVaultV2Helper

Git Source

Helper functions for Yearn Vault V2 contracts. Since Yearn Vault V2 contracts are not ERC-4626 compliant, they do not provide previewDeposit, previewMint, previewRedeem, and previewWithdraw functions. This library provides these functions for previewing share based deposit/mint/redeem/withdraw estimations.

These functions are only to be used off-chain for previewing. Due to how Yearn Vault V2 contracts work, share based withdraw/redeem estimations may not be accurate if the vault incurs a loss, thus share price changes. Coverage is currently disabled for this library due to forge limitations. TODO: Once the fix PR is merged, https://github.com/foundry-rs/foundry/pull/7510 coverage should be re-enabled.

Functions

freeFunds

Calculates the currently free funds in a Yearn Vault V2 contract.

This is based on Yearn Vault V2 contract's free funds calculation logic. https://github.com/yearn/yearn-vaults/blob/97ca1b2e4fcf20f4be0ff456dabd020bfeb6697b/contracts/Vault.vy#L844-L847

function freeFunds(IYearnVaultV2 vault) internal view returns (uint256);

Parameters

Name	Type	Description
`vault`	`IYearnVaultV2`	The Yearn Vault V2 contract.

Returns

Name	Type	Description
`<none>`	`uint256`	The free funds in the vault.

previewDeposit

Preview the amount of shares to be issued for a given deposit amount.

function previewDeposit(IYearnVaultV2 vault, uint256 assetsIn) internal view returns (uint256);

Parameters

Name	Type	Description
`vault`	`IYearnVaultV2`	The Yearn Vault V2 contract.
`assetsIn`	`uint256`	The amount of assets to be deposited.

Returns

Name	Type	Description
`<none>`	`uint256`	The number of shares that would be issued for the deposited assets.

previewMint

Preview the amount of assets required to mint a given amount of shares.

function previewMint(IYearnVaultV2 vault, uint256 sharesOut) internal view returns (uint256);

Parameters

Name	Type	Description
`vault`	`IYearnVaultV2`	The Yearn Vault V2 contract.
`sharesOut`	`uint256`	The number of shares to be minted.

Returns

Name	Type	Description
`<none>`	`uint256`	The amount of assets required to mint the specified number of shares.

previewRedeem

Preview the amount of assets to be received for redeeming a given amount of shares.

function previewRedeem(IYearnVaultV2 vault, uint256 sharesIn) internal view returns (uint256);

Parameters

Name	Type	Description
`vault`	`IYearnVaultV2`	The Yearn Vault V2 contract.
`sharesIn`	`uint256`	The number of shares to be redeemed.

Returns

Name	Type	Description
`<none>`	`uint256`	The amount of assets that would be received for the redeemed shares.

previewWithdraw

Preview the number of shares to be redeemed for a given withdrawal amount of assets.

function previewWithdraw(IYearnVaultV2 vault, uint256 assetsOut) internal view returns (uint256);

Parameters

Name	Type	Description
`vault`	`IYearnVaultV2`	The Yearn Vault V2 contract.
`assetsOut`	`uint256`	The amount of assets to be withdrawn.

Returns

Name	Type	Description
`<none>`	`uint256`	The number of shares that would be redeemed for the withdrawn assets.