I have an extended ERC20 contract with ERC827 functions, which are overrides of ERC20 with an extra callback parameter.

I have these two pairs of base/override functions:


    function approve(address _spender, uint _value) public returns (bool success) {
        allowed[msg.sender][_spender] = _value;
        Approval(msg.sender, _spender, _value);
        return true;


    function approve(address _spender, uint _value, bytes _data) public returns (bool) {
        require(_spender != address(this));
        super.approve(_spender, _value);
        return true;


    function increaseApproval(address _spender, uint _addedValue) public returns (bool) {
        allowed[msg.sender][_spender] = allowed[msg.sender][_spender].add(_addedValue);
        Approval(msg.sender, _spender, allowed[msg.sender][_spender]);
        return true;


    function increaseApproval(address _spender, uint _addedValue, bytes _data) public returns (bool) {
        require(_spender != address(this));
        super.increaseApproval(_spender, _addedValue);
        return true;

Unit test:

    it ("Test increasing allowance", async () => {
        // First, transfer 1000 coins from owner to user1
        await instance.transfer(user1Address, 1000, {from: ownerAddress});
        // Allow owner to spend 420 tokens from user1 balance
        await instance.approve(ownerAddress, 420, { from: user1Address });
        // Now increase that approval by 47 tokens
        await instance.increaseApproval(ownerAddress, 47, { from: user1Address });
        // Check owner's allowance for spending user1's tokens - should be 467
        const allowance = instance.allowance(user1Address, ownerAddress);

        assert.equal(allowance, 467);

When in unint test I make a call to approve with two arguments, it works fine, but when I make a call to increaseApproval with two arguments, it throws the following error:

Error: Invalid number of arguments to Solidity function at Object.InvalidNumberOfSolidityArgs (/Users/user/.local/share/npm/lib/node_modules/truffle/build/webpack:/~/web3/lib/web3/errors.js:25:1) at SolidityFunction.validateArgs (/Users/user/.local/share/npm/lib/node_modules/truffle/build/webpack:/~/web3/lib/web3/function.js:74:1) at SolidityFunction.toPayload (/Users/user/.local/share/npm/lib/node_modules/truffle/build/webpack:/~/web3/lib/web3/function.js:90:1) at SolidityFunction.sendTransaction (/Users/user/.local/share/npm/lib/node_modules/truffle/build/webpack:/~/web3/lib/web3/function.js:163:1) at SolidityFunction.execute (/Users/user/.local/share/npm/lib/node_modules/truffle/build/webpack:/~/web3/lib/web3/function.js:256:1) at /Users/user/.local/share/npm/lib/node_modules/truffle/build/webpack:/~/truffle-contract/contract.js:202:1 at /Users/user/.local/share/npm/lib/node_modules/truffle/build/webpack:/~/truffle-contract/contract.js:155:1 at process._tickCallback (internal/process/next_tick.js:109:7)

But if I call it with three arguments (as in its override) it works fine.

Any ideas why approve can be called as the base function (with 2 arguments) but increaseApproval fails with two arguments and wants three (as in the override)

The actual code is here: https://github.com/path-foundation/path-token/blob/master/contracts/PathToken.sol

And the unit tests are here: https://github.com/path-foundation/path-token/blob/master/test/TestPathToken.js

  • Can you add your unit-testing code? – Roman Frolov Feb 25 '18 at 3:13
  • @RomanFrolov - added. Thank you for taking a look, Roman! – Andrey Feb 25 '18 at 3:16
  • Does it work if you reomve { from: user1Address }? It could the that library is getting confused with the options parameter. – ivicaa Feb 25 '18 at 5:34
  • @ivicaa - still doesn't work – Andrey Feb 26 '18 at 5:01

I'm also getting this using Open Zeppelin's ERC721BasicToken.sol

There are:

function safeTransferFrom(address _from, address _to, uint256 _tokenId) public canTransfer(_tokenId) { safeTransferFrom(_from, _to, _tokenId, ""); } And

function safeTransferFrom(address _from, address _to, uint256 _tokenId, bytes _data) public canTransfer(_tokenId) { transferFrom(_from, _to, _tokenId); require(checkAndCallSafeTransfer(_from, _to, _tokenId, _data)); } This call fails:

const tokenId = await sampleNFT.safeTransferFrom.call(alice, composable.address, 1, 1); With this error:

Contract: Composable should safeTransferFrom: Error: Invalid number of arguments to Solidity function

  • Not enough room at add as a comment, sorry no answer found yet. – mattdlockyer Apr 27 '18 at 14:20
  • 2
    Hey Matt :) So the issue is - truffle is using an older version of web3 (<1.0) which doesn't support function overrides. Truffle guys told me it will be fixed in the next major version update but they have no ETA as web3 v 1.0 breaks a lot of things. – Andrey Apr 27 '18 at 14:32
  • One way to overcome that in the mean time is to always invoke the override function, and pass 0x0 for the data argument. – Andrey Apr 27 '18 at 14:33

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