Function: send(uint32 _dstEid, string calldata _message, bytes calldata _options)

This function allows any user to send any message to the application in the _dstEid chain.

Inputs

• _dstEid

  • Control: Full control.

  • Constraints: peers should contains the _dstEid. Only owner can set up.

  • Impact: The ID of the destination chain where the message will be sent.

• _message

  • Control: Full control.

  • Constraints: N/A.

  • Impact: The message to be sent.

• _options

  • Control: Full control.

  • Constraints: Should be OPTION_TYPE_3.

  • Impact: Determines the gas limit and amount of msg.value to include.

Branches and code coverage

Intended branches

• _message is sent successfully.

  Test coverage

• The caller pays more fees than necessary and receives the excess back.

  Test coverage

Negative behavior

• The provided fee is not enough.

  Negative test

• The message is empty.

  Negative test

• There is an invalid type of additional _options.

  Negative test

• _dstEid is not supported.

  Negative test

Function call analysis

• _lzSend(_dstEid, _payload, options, MessagingFee(msg.value, 0), payable(msg.sender)) -> endpoint.send{ value: messageValue }(MessagingParams(_dstEid, _getPeerOrRevert(_dstEid), _message, _options, _fee.lzTokenFee > 0),_refundAddress);

  • What is controllable? _dstEid.

  • If the return value is controllable, how is it used and how can it go wrong? receipt is just used to be returned from this function. Contains GUID, nonce, and fee.

  • What happens if it reverts, reenters or does other unusual control flow? If the provided fee is greater than necessary, the caller will receive excess back.

• _lzSend(_dstEid, _payload, options, MessagingFee(msg.value, 0), payable(msg.sender)) -> _getPeerOrRevert(_dstEid)

  • What is controllable? _dstEid.

  • If the return value is controllable, how is it used and how can it go wrong? Returns the peer address where the message will be delivered.

  • What happens if it reverts, reenters or does other unusual control flow? Reverts if _dstEid is not supported.