Function: _withdraw(address _l2Token, address _to, uint256 _amount, byte[] _data, uint256 _gasLimit)

Facilitates the withdrawing of tokens from L2 to L1.

Inputs

• _l2Token

  • Control: Fully controlled by the caller.

  • Constraints: Ensure it is a supported L2 token.

  • Impact: The L2 token to be withdrawn.

• _to

  • Control: Fully controlled by the caller.

  • Constraints: None.

  • Impact: The address to which the tokens will be sent.

• _amount

  • Control: Fully controlled by the caller.

  • Constraints: Ensured from possesses at least _amount tokens.

  • Impact: The amount of tokens to be withdrawn.

• _data

  • Control: Fully controlled by the caller.

  • Constraints: None.

  • Impact: The data to be forwarded cross-chain.

• _gasLimit

  • Control: Fully controlled by the caller.

  • Constraints: None.

  • Impact: The gas limit for the cross-chain transaction.

Branches and code coverage (including function calls)

Intended branches

• Ensure that l2Token is supported.

  Test coverage

• Ensure that withdrawals are enabled.

  Test coverage

• Burn the amount of tokens from from.

  Test coverage

• Generate the message to be sent to L1.

  Test coverage

• Forward the message to L1.

  Test coverage

Negative behavior

• Should not allow sending tokens if there is not enough balance. Handled in burn.

  Test coverage