I have two questions. My contract has compiled and deployed successfully both using remix and truffle. However: q1) remix returns an empty array of ABI.
Also, after I hit compile the contract at the bottom left changes back to Context.sol instead of ww1.sol.
q2) in Truffle, the contract's json file in build/contracts/ folder has the abi which is below:
[{ "anonymous": false, "inputs": [ { "indexed": true, "internalType": "address", "name": "owner", "type": "address" }, { "indexed": true, "internalType": "address", "name": "spender", "type": "address" }, { "indexed": false, "internalType": "uint256", "name": "value", "type": "uint256" } ], "name": "Approval", "type": "event" }, { "anonymous": false, "inputs": [ { "indexed": true, "internalType": "address", "name": "delegator", "type": "address" }, { "indexed": true, "internalType": "address", "name": "fromDelegate", "type": "address" }, { "indexed": true, "internalType": "address", "name": "toDelegate", "type": "address" } ], "name": "DelegateChanged", "type": "event" }, { "anonymous": false, "inputs": [ { "indexed": true, "internalType": "address", "name": "delegate", "type": "address" }, { "indexed": false, "internalType": "uint256", "name": "previousBalance", "type": "uint256" }, { "indexed": false, "internalType": "uint256", "name": "newBalance", "type": "uint256" } ], "name": "DelegateVotesChanged", "type": "event" }, { "anonymous": false, "inputs": [ { "indexed": true, "internalType": "address", "name": "previousOwner", "type": "address" }, { "indexed": true, "internalType": "address", "name": "newOwner", "type": "address" } ], "name": "OwnershipTransferred", "type": "event" }, { "anonymous": false, "inputs": [ { "indexed": true, "internalType": "address", "name": "from", "type": "address" }, { "indexed": true, "internalType": "address", "name": "to", "type": "address" }, { "indexed": false, "internalType": "uint256", "name": "value", "type": "uint256" } ], "name": "Transfer", "type": "event" }, { "inputs": [], "name": "DELEGATION_TYPEHASH", "outputs": [ { "internalType": "bytes32", "name": "", "type": "bytes32" } ], "stateMutability": "view", "type": "function", "constant": true }, { "inputs": [], "name": "DOMAIN_TYPEHASH", "outputs": [ { "internalType": "bytes32", "name": "", "type": "bytes32" } ], "stateMutability": "view", "type": "function", "constant": true }, { "inputs": [ { "internalType": "address", "name": "owner", "type": "address" }, { "internalType": "address", "name": "spender", "type": "address" } ], "name": "allowance", "outputs": [ { "internalType": "uint256", "name": "", "type": "uint256" } ], "stateMutability": "view", "type": "function", "constant": true }, { "inputs": [ { "internalType": "address", "name": "spender", "type": "address" }, { "internalType": "uint256", "name": "amount", "type": "uint256" } ], "name": "approve", "outputs": [ { "internalType": "bool", "name": "", "type": "bool" } ], "stateMutability": "nonpayable", "type": "function" }, { "inputs": [ { "internalType": "address", "name": "account", "type": "address" } ], "name": "balanceOf", "outputs": [ { "internalType": "uint256", "name": "", "type": "uint256" } ], "stateMutability": "view", "type": "function", "constant": true }, { "inputs": [ { "internalType": "address", "name": "", "type": "address" }, { "internalType": "uint32", "name": "", "type": "uint32" } ], "name": "checkpoints", "outputs": [ { "internalType": "uint32", "name": "fromBlock", "type": "uint32" }, { "internalType": "uint256", "name": "votes", "type": "uint256" } ], "stateMutability": "view", "type": "function", "constant": true }, { "inputs": [], "name": "decimals", "outputs": [ { "internalType": "uint8", "name": "", "type": "uint8" } ], "stateMutability": "view", "type": "function", "constant": true }, { "inputs": [ { "internalType": "address", "name": "spender", "type": "address" }, { "internalType": "uint256", "name": "subtractedValue", "type": "uint256" } ], "name": "decreaseAllowance", "outputs": [ { "internalType": "bool", "name": "", "type": "bool" } ], "stateMutability": "nonpayable", "type": "function" }, { "inputs": [], "name": "getOwner", "outputs": [ { "internalType": "address", "name": "", "type": "address" } ], "stateMutability": "view", "type": "function", "constant": true }, { "inputs": [ { "internalType": "address", "name": "spender", "type": "address" }, { "internalType": "uint256", "name": "addedValue", "type": "uint256" } ], "name": "increaseAllowance", "outputs": [ { "internalType": "bool", "name": "", "type": "bool" } ], "stateMutability": "nonpayable", "type": "function" }, { "inputs": [], "name": "name", "outputs": [ { "internalType": "string", "name": "", "type": "string" } ], "stateMutability": "view", "type": "function", "constant": true }, { "inputs": [ { "internalType": "address", "name": "", "type": "address" } ], "name": "nonces", "outputs": [ { "internalType": "uint256", "name": "", "type": "uint256" } ], "stateMutability": "view", "type": "function", "constant": true }, { "inputs": [ { "internalType": "address", "name": "", "type": "address" } ], "name": "numCheckpoints", "outputs": [ { "internalType": "uint32", "name": "", "type": "uint32" } ], "stateMutability": "view", "type": "function", "constant": true }, { "inputs": [], "name": "owner", "outputs": [ { "internalType": "address", "name": "", "type": "address" } ], "stateMutability": "view", "type": "function", "constant": true }, { "inputs": [], "name": "renounceOwnership", "outputs": [], "stateMutability": "nonpayable", "type": "function" }, { "inputs": [], "name": "symbol", "outputs": [ { "internalType": "string", "name": "", "type": "string" } ], "stateMutability": "view", "type": "function", "constant": true }, { "inputs": [], "name": "totalSupply", "outputs": [ { "internalType": "uint256", "name": "", "type": "uint256" } ], "stateMutability": "view", "type": "function", "constant": true }, { "inputs": [ { "internalType": "address", "name": "recipient", "type": "address" }, { "internalType": "uint256", "name": "amount", "type": "uint256" } ], "name": "transfer", "outputs": [ { "internalType": "bool", "name": "", "type": "bool" } ], "stateMutability": "nonpayable", "type": "function" }, { "inputs": [ { "internalType": "address", "name": "sender", "type": "address" }, { "internalType": "address", "name": "recipient", "type": "address" }, { "internalType": "uint256", "name": "amount", "type": "uint256" } ], "name": "transferFrom", "outputs": [ { "internalType": "bool", "name": "", "type": "bool" } ], "stateMutability": "nonpayable", "type": "function" }, { "inputs": [ { "internalType": "address", "name": "newOwner", "type": "address" } ], "name": "transferOwnership", "outputs": [], "stateMutability": "nonpayable", "type": "function" }, { "inputs": [ { "internalType": "address", "name": "_to", "type": "address" }, { "internalType": "uint256", "name": "_amount", "type": "uint256" } ], "name": "mint", "outputs": [], "stateMutability": "nonpayable", "type": "function" }, { "inputs": [ { "internalType": "uint256", "name": "amount", "type": "uint256" } ], "name": "mint", "outputs": [ { "internalType": "bool", "name": "", "type": "bool" } ], "stateMutability": "nonpayable", "type": "function" }, { "inputs": [ { "internalType": "address", "name": "delegator", "type": "address" } ], "name": "delegates", "outputs": [ { "internalType": "address", "name": "", "type": "address" } ], "stateMutability": "view", "type": "function", "constant": true }, { "inputs": [ { "internalType": "address", "name": "delegatee", "type": "address" } ], "name": "delegate", "outputs": [], "stateMutability": "nonpayable", "type": "function" }, { "inputs": [ { "internalType": "address", "name": "delegatee", "type": "address" }, { "internalType": "uint256", "name": "nonce", "type": "uint256" }, { "internalType": "uint256", "name": "expiry", "type": "uint256" }, { "internalType": "uint8", "name": "v", "type": "uint8" }, { "internalType": "bytes32", "name": "r", "type": "bytes32" }, { "internalType": "bytes32", "name": "s", "type": "bytes32" } ], "name": "delegateBySig", "outputs": [], "stateMutability": "nonpayable", "type": "function" }, { "inputs": [ { "internalType": "address", "name": "account", "type": "address" } ], "name": "getCurrentVotes", "outputs": [ { "internalType": "uint256", "name": "", "type": "uint256" } ], "stateMutability": "view", "type": "function", "constant": true }, { "inputs": [ { "internalType": "address", "name": "account", "type": "address" }, { "internalType": "uint256", "name": "blockNumber", "type": "uint256" } ], "name": "getPriorVotes", "outputs": [ { "internalType": "uint256", "name": "", "type": "uint256" } ], "stateMutability": "view", "type": "function", "constant": true }]
When I use this abi and try to verify and publish my contract on testnet, I get the following error:
Error! Invalid constructor arguments provided. Please verify that they are in ABI-encoded format
How can I get the correct format abi, so that I can verify my contract.
UPDATE: I tried to use truffle-plugin-verify to verify the smart contract on truffle and it gives me the following error. It is again pointing towards the Context.sol file but I fail to understand why because the file is visible to me in the GSN folder.
Cannot find module '@pancakeswap/pancake-swap-lib/contracts/GSN/Context.sol'
Require stack:
- C:\Users\DELL\node_modules\truffle-plugin-verify\verify.js
- C:\Users\DELL\AppData\Roaming\npm\node_modules\truffle\node_modules\original-require\index.js
- C:\Users\DELL\AppData\Roaming\npm\node_modules\truffle\build\cli.bundled.js
Failed to verify 1 contract(s): NiftToken
NiftToken.sol
//SPDX-License-Identifier: MIT
pragma solidity 0.6.12;
import "@pancakeswap/pancake-swap-lib/contracts/token/BEP20/BEP20.sol";
// NiftToken with Governance.
contract NiftToken is BEP20("NiftySwap Token", "NIFT") {
/// @notice Creates `_amount` token to `_to`. Must only be called by the owner (MasterChef).
function mint(address _to, uint256 _amount) public onlyOwner {
_mint(_to, _amount);
_moveDelegates(address(0), _delegates[_to], _amount);
}
// Copied and modified from YAM code:
// https://github.com/yam-finance/yam-protocol/blob/master/contracts/token/YAMGovernanceStorage.sol
// https://github.com/yam-finance/yam-protocol/blob/master/contracts/token/YAMGovernance.sol
// Which is copied and modified from COMPOUND:
// https://github.com/compound-finance/compound-protocol/blob/master/contracts/Governance/Comp.sol
/// @notice A record of each accounts delegate
mapping(address => address) internal _delegates;
/// @notice A checkpoint for marking number of votes from a given block
struct Checkpoint {
uint32 fromBlock;
uint256 votes;
}
/// @notice A record of votes checkpoints for each account, by index
mapping(address => mapping(uint32 => Checkpoint)) public checkpoints;
/// @notice The number of checkpoints for each account
mapping(address => uint32) public numCheckpoints;
/// @notice The EIP-712 typehash for the contract's domain
bytes32 public constant DOMAIN_TYPEHASH =
keccak256(
"EIP712Domain(string name,uint256 chainId,address verifyingContract)"
);
/// @notice The EIP-712 typehash for the delegation struct used by the contract
bytes32 public constant DELEGATION_TYPEHASH =
keccak256("Delegation(address delegatee,uint256 nonce,uint256 expiry)");
/// @notice A record of states for signing / validating signatures
mapping(address => uint256) public nonces;
/// @notice An event thats emitted when an account changes its delegate
event DelegateChanged(
address indexed delegator,
address indexed fromDelegate,
address indexed toDelegate
);
/// @notice An event thats emitted when a delegate account's vote balance changes
event DelegateVotesChanged(
address indexed delegate,
uint256 previousBalance,
uint256 newBalance
);
/**
* @notice Delegate votes from `msg.sender` to `delegatee`
* @param delegator The address to get delegatee for
*/
function delegates(address delegator) external view returns (address) {
return _delegates[delegator];
}
/**
* @notice Delegate votes from `msg.sender` to `delegatee`
* @param delegatee The address to delegate votes to
*/
function delegate(address delegatee) external {
return _delegate(msg.sender, delegatee);
}
/**
* @notice Delegates votes from signatory to `delegatee`
* @param delegatee The address to delegate votes to
* @param nonce The contract state required to match the signature
* @param expiry The time at which to expire the signature
* @param v The recovery byte of the signature
* @param r Half of the ECDSA signature pair
* @param s Half of the ECDSA signature pair
*/
function delegateBySig(
address delegatee,
uint256 nonce,
uint256 expiry,
uint8 v,
bytes32 r,
bytes32 s
) external {
bytes32 domainSeparator =
keccak256(
abi.encode(
DOMAIN_TYPEHASH,
keccak256(bytes(name())),
getChainId(),
address(this)
)
);
bytes32 structHash =
keccak256(
abi.encode(DELEGATION_TYPEHASH, delegatee, nonce, expiry)
);
bytes32 digest =
keccak256(
abi.encodePacked("\x19\x01", domainSeparator, structHash)
);
address signatory = ecrecover(digest, v, r, s);
require(
signatory != address(0),
"NIFT::delegateBySig: invalid signature"
);
require(
nonce == nonces[signatory]++,
"NIFT::delegateBySig: invalid nonce"
);
require(now <= expiry, "NIFT::delegateBySig: signature expired");
return _delegate(signatory, delegatee);
}
/**
* @notice Gets the current votes balance for `account`
* @param account The address to get votes balance
* @return The number of current votes for `account`
*/
function getCurrentVotes(address account) external view returns (uint256) {
uint32 nCheckpoints = numCheckpoints[account];
return
nCheckpoints > 0 ? checkpoints[account][nCheckpoints - 1].votes : 0;
}
/**
* @notice Determine the prior number of votes for an account as of a block number
* @dev Block number must be a finalized block or else this function will revert to prevent misinformation.
* @param account The address of the account to check
* @param blockNumber The block number to get the vote balance at
* @return The number of votes the account had as of the given block
*/
function getPriorVotes(address account, uint256 blockNumber)
external
view
returns (uint256)
{
require(
blockNumber < block.number,
"NIFT::getPriorVotes: not yet determined"
);
uint32 nCheckpoints = numCheckpoints[account];
if (nCheckpoints == 0) {
return 0;
}
// First check most recent balance
if (checkpoints[account][nCheckpoints - 1].fromBlock <= blockNumber) {
return checkpoints[account][nCheckpoints - 1].votes;
}
// Next check implicit zero balance
if (checkpoints[account][0].fromBlock > blockNumber) {
return 0;
}
uint32 lower = 0;
uint32 upper = nCheckpoints - 1;
while (upper > lower) {
uint32 center = upper - (upper - lower) / 2; // ceil, avoiding overflow
Checkpoint memory cp = checkpoints[account][center];
if (cp.fromBlock == blockNumber) {
return cp.votes;
} else if (cp.fromBlock < blockNumber) {
lower = center;
} else {
upper = center - 1;
}
}
return checkpoints[account][lower].votes;
}
function _delegate(address delegator, address delegatee) internal {
address currentDelegate = _delegates[delegator];
uint256 delegatorBalance = balanceOf(delegator); // balance of underlying NIFTs (not scaled);
_delegates[delegator] = delegatee;
emit DelegateChanged(delegator, currentDelegate, delegatee);
_moveDelegates(currentDelegate, delegatee, delegatorBalance);
}
function _moveDelegates(
address srcRep,
address dstRep,
uint256 amount
) internal {
if (srcRep != dstRep && amount > 0) {
if (srcRep != address(0)) {
// decrease old representative
uint32 srcRepNum = numCheckpoints[srcRep];
uint256 srcRepOld =
srcRepNum > 0
? checkpoints[srcRep][srcRepNum - 1].votes
: 0;
uint256 srcRepNew = srcRepOld.sub(amount);
_writeCheckpoint(srcRep, srcRepNum, srcRepOld, srcRepNew);
}
if (dstRep != address(0)) {
// increase new representative
uint32 dstRepNum = numCheckpoints[dstRep];
uint256 dstRepOld =
dstRepNum > 0
? checkpoints[dstRep][dstRepNum - 1].votes
: 0;
uint256 dstRepNew = dstRepOld.add(amount);
_writeCheckpoint(dstRep, dstRepNum, dstRepOld, dstRepNew);
}
}
}
function _writeCheckpoint(
address delegatee,
uint32 nCheckpoints,
uint256 oldVotes,
uint256 newVotes
) internal {
uint32 blockNumber =
safe32(
block.number,
"NIFT::_writeCheckpoint: block number exceeds 32 bits"
);
if (
nCheckpoints > 0 &&
checkpoints[delegatee][nCheckpoints - 1].fromBlock == blockNumber
) {
checkpoints[delegatee][nCheckpoints - 1].votes = newVotes;
} else {
checkpoints[delegatee][nCheckpoints] = Checkpoint(
blockNumber,
newVotes
);
numCheckpoints[delegatee] = nCheckpoints + 1;
}
emit DelegateVotesChanged(delegatee, oldVotes, newVotes);
}
function safe32(uint256 n, string memory errorMessage)
internal
pure
returns (uint32)
{
require(n < 2**32, errorMessage);
return uint32(n);
}
function getChainId() internal pure returns (uint256) {
uint256 chainId;
assembly {
chainId := chainid()
}
return chainId;
}
}
Context.sol
// SPDX-License-Identifier: GPL-3.0-or-later
pragma solidity >=0.4.0;
/*
* @dev Provides information about the current execution context, including the
* sender of the transaction and its data. While these are generally available
* via msg.sender and msg.data, they should not be accessed in such a direct
* manner, since when dealing with GSN meta-transactions the account sending and
* paying for execution may not be the actual sender (as far as an application
* is concerned).
*
* This contract is only required for intermediate, library-like contracts.
*/
contract Context {
// Empty internal constructor, to prevent people from mistakenly deploying
// an instance of this contract, which should be used via inheritance.
constructor() internal {}
function _msgSender() internal view returns (address payable) {
return msg.sender;
}
function _msgData() internal view returns (bytes memory) {
this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691
return msg.data;
}
}
