For the Bridge contract which inherits the Escrow. Safe Transfer is used multiple times, However it is not implemented anywhere in the Bridge contract
The Bridge enables transfer of ERC721 and ERC1155 tokens. And it uses the safe transfer method for the ERC1155 token. This means the contract should implement this:
interface ERC1155TokenReceiver {
@notice Handle the receipt of a single ERC1155 token type.
@dev An ERC1155-compliant smart contract MUST call this function on the token recipient contract, at the end of a `safeTransferFrom` after the balance has been updated.
This function MUST return `bytes4(keccak256("onERC1155Received(address,address,uint256,uint256,bytes)"))` (i.e. 0xf23a6e61) if it accepts the transfer.
This function MUST revert if it rejects the transfer.
Return of any other value than the prescribed keccak256 generated value MUST result in the transaction being reverted by the caller.
@param _operator The address which initiated the transfer (i.e. msg.sender)
@param _from The address which previously owned the token
@param _id The ID of the token being transferred
@param _value The amount of tokens being transferred
@param _data Additional data with no specified format
@return `bytes4(keccak256("onERC1155Received(address,address,uint256,uint256,bytes)"))`
*/
function onERC1155Received(address _operator, address _from, uint256 _id, uint256 _value, bytes calldata _data) external returns(bytes4);
@notice Handle the receipt of multiple ERC1155 token types.
@dev An ERC1155-compliant smart contract MUST call this function on the token recipient contract, at the end of a `safeBatchTransferFrom` after the balances have been updated.
This function MUST return `bytes4(keccak256("onERC1155BatchReceived(address,address,uint256[],uint256[],bytes)"))` (i.e. 0xbc197c81) if it accepts the transfer(s).
This function MUST revert if it rejects the transfer(s).
Return of any other value than the prescribed keccak256 generated value MUST result in the transaction being reverted by the caller.
@param _operator The address which initiated the batch transfer (i.e. msg.sender)
@param _from The address which previously owned the token
@param _ids An array containing ids of each token being transferred (order and length must match _values array)
@param _values An array containing amounts of each token being transferred (order and length must match _ids array)
@param _data Additional data with no specified format
@return `bytes4(keccak256("onERC1155BatchReceived(address,address,uint256[],uint256[],bytes)"))`
*/
function onERC1155BatchReceived(address _operator, address _from, uint256[] calldata _ids, uint256[] calldata _values, bytes calldata _data) external returns(bytes4);
}
however it doesn't.
It also does not implement the ERC721 receiver.
