Linear erc20 swap offer enforcer #26
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This is my current best draft of a preprompt to help development of caveat enforcers. It will need to be kept up to date when we change interfaces. I believe I have it up to date with main now.
| bytes4 selector = bytes4(callData_[0:4]); | ||
| require(selector == IERC20.transfer.selector || selector == IERC20.transferFrom.selector, "SwapOfferEnforcer:invalid-method"); | ||
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| uint256 amount = uint256(bytes32(callData_[36:68])); |
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The amount should be extracted from different ranges if it is transfer [36:68] or transferFrom [68:100]
| require(offer.tokenIn == terms.tokenIn && offer.tokenOut == terms.tokenOut && | ||
| offer.amountIn == terms.amountIn && offer.amountOut == terms.amountOut && | ||
| offer.recipient == terms.recipient, | ||
| "SwapOfferEnforcer:terms-mismatch"); | ||
| } |
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I'm not sure if it would be more expensive to read it like this rather than to create a copy in memory.
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It would be good to have a test for erc20.transferFrom
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| struct SwapOfferArgs { | ||
| uint256 claimedAmount; | ||
| IDelegationManager delegationManager; |
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It is safer not to allow the redeemer to provide the delegationManager address in the args, instead always use msg.sender as the other enforcers. As it is right now someone could call the beforeHook directly and modify values that he shouldn't.
| override | ||
| onlySingleExecutionMode(_mode) | ||
| { | ||
| SwapOfferArgs memory args = abi.decode(_args, (SwapOfferArgs)); |
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Underscore in variable names
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| require(offer.amountOutFilled + amount <= offer.amountOut, "SwapOfferEnforcer:exceeds-output-amount"); | ||
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| amountInFilled_ = offer.amountInFilled + _claimedAmount; |
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I wonder why we read these offer.amountInFilled and offer.amountOutFilled instead of resetting them to 0 if the offer already existed
Allows offering an amount of an ERC20 in exchange for any number of partial orders of another ERC20 at a given rate.