RUSDT -> USDT0 converter #565
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Pull request overview
This PR implements a RUSDT to USDT0 token swap contract for the Rootstock network. The contract acts as an ERC777 recipient that automatically converts incoming RUSDT tokens to USDT0 tokens at a 1:1 ratio (accounting for decimal differences).
Key changes:
- Added
RootstockUsdtSwap.solcontract that implements ERC777 recipient interface to handle automatic token swaps - Created comprehensive test suite covering success cases, error conditions, and rescue functionality
- Added deployment script with placeholder addresses for the three required roles
Reviewed changes
Copilot reviewed 3 out of 3 changed files in this pull request and generated 4 comments.
| File | Description |
|---|---|
| contracts/utils/RootstockUsdtSwap.sol | Core swap contract implementing ERC777 recipient hook, decimal conversion logic, and emergency rescue function |
| tests-foundry/RootstockUsdtSwap.t.sol | Complete test coverage including mock contracts, success scenarios, validation checks, and edge cases |
| script/DeployRootstockUsdtSwap.s.sol | Deployment script with hardcoded test addresses for the three contract roles |
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| require(allowance >= usdt0Amount, "USDT0 allowance too low"); | ||
| uint256 providerBalance = USDT0.balanceOf(usdt0Provider); | ||
| require(providerBalance >= usdt0Amount, "USDT0 provider balance too low"); | ||
| bool success = USDT0.transferFrom(usdt0Provider, from, usdt0Amount); |
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Better use SafeERC20 library here
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SafeERC20 is used to cover cases with not fully compatible ERC20, like USDT on Ethereum transfer function doesn't return bool which would at most lead to revert of the whole swap.
but based on the technical documentation for USDT0 on Rootstock, it is explicitly designed to be fully ERC-20 compliant, which means it is safe to call transferFrom and check its boolean return value, meaning this is a gas saving approach in this particular case.
| uint256 allowance = USDT0.allowance(usdt0Provider, address(this)); | ||
| require(allowance >= usdt0Amount, "USDT0 allowance too low"); | ||
| uint256 providerBalance = USDT0.balanceOf(usdt0Provider); | ||
| require(providerBalance >= usdt0Amount, "USDT0 provider balance too low"); |
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This is not required, since we will check the below transfer whether it's failed or not.
But in case you want to keep this for the better revert message, then i am fine
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this is just to revert early in case there is not enough balance or allowance and for clear revert msg.
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