withdraw

Function Type: external
Function Signature: withdraw(address,uint256)
Returns: void

Withdraws host chain coins or ERC20 tokens from the EVVM virtual blockchain back to the user's wallet on the host blockchain. This function includes principal token protection to prevent withdrawal of the ecosystem's core token.

Parameters

Parameter	Type	Description
token	address	Token contract address or address(0) for host chain coin
amount	uint256	Amount to withdraw

Workflow

1. Principal Token Protection: Checks if the token is the ecosystem's principal token using getEvvmMetadata().principalTokenAddress. Reverts with PrincipalTokenIsNotWithdrawable() if attempting to withdraw the principal token.
2. EVVM Balance Verification: Validates that the user has sufficient balance in the EVVM virtual blockchain using getBalance(msg.sender, token) < amount. Reverts with InsufficientBalance() if the user lacks adequate funds.
3. Conditional Transfer Flow:
   • Host Chain Coin Withdrawal (token == address(0)):
     • Calls removeAmountFromUser(msg.sender, address(0), amount) to debit the user's EVVM balance
     • Uses SafeTransferLib.safeTransferETH(msg.sender, amount) to transfer host chain coins from Treasury to user on the host blockchain
   • ERC20 Withdrawal (token != address(0)):
     • Calls removeAmountFromUser(msg.sender, token, amount) to debit the user's EVVM balance
     • Executes IERC20(token).transfer(msg.sender, amount) to send tokens from Treasury to user on the host blockchain

Errors

• PrincipalTokenIsNotWithdrawable() — Reverted when attempting to withdraw the configured Principal Token (see getEvvmMetadata().principalTokenAddress).
• InsufficientBalance() — Reverted when getBalance(msg.sender, token) < amount.

Security & Notes

• The contract updates EVVM balances via removeAmountFromUser(...) before performing the external token/ETH transfer. This is a safe ordering (state change before external call) and helps prevent reentrancy issues on withdraw paths.
• For ETH transfers the contract uses SafeTransferLib.safeTransferETH which is recommended. For ERC20 transfers it uses IERC20(token).transfer(...) — consider using SafeTransferLib.safeTransfer for robustness against non-compliant tokens and to detect transfer failures.
• The correctness of removeAmountFromUser/addAmountToUser depends on the EVVM core contract having the Treasury as the authorized caller (i.e., Evvm.treasuryAddress must be set). Tests should ensure that Evvm is configured so that these treasury calls succeed.
• Add unit tests that cover: withdrawing the principal token (should revert), insufficient balance, successful ETH withdraw, successful ERC20 withdraw, and token transfer failures.