Looks like function overrides are not supported by test framework

• I’ve asked for help in the Truffle Gitter before filing this issue.

---

Issue

If a contract has an override function, unit tests for that function break.

Steps to Reproduce

Simplest example I could create to reproduce the issue

Contract:

pragma solidity ^0.4.18;

contract BaseExample {
    function approve(address _spender, uint _value) public returns (bool) {
        return true;
    }

    function increaseApproval(address _spender, uint _addedValue) public returns (bool) {
        return true;
    }
}

contract OverrideExample is BaseExample {

    function approve(address _spender, uint _value, bytes _data) public returns (bool) {
        return true;
    }

    function increaseApproval(address _spender, uint _addedValue, bytes _data) public returns (bool) {
        return true;
    }
}

Unit test:

const OverrideExample = artifacts.require("OverrideExample");

contract("OverrideExample", (accounts) => {
    let instance;

    before(async () => {
        instance = await OverrideExample.deployed();
    })

    it("Test lowercase method - base", async () => {
        await instance.approve(0x0, 1);
    });

    it("Test lowercase method - override", async () => {
        await instance.approve(0x0, 1, 0x0); // BREAKS
    });

    it("Test camelCase method - base", async () => {
        await instance.increaseApproval(0x0, 1); // BREAKS
    });

    it("Test camelCase method - override", async () => {
        await instance.increaseApproval(0x0, 1, 0x0);
    });
})

Run truffle migrate and then truffle test.

Expected Behavior

No errors, all tests pass

Actual Results

When I run truffle migrate and then truffle test, I get the following error:

1) Contract: OverrideExample Test lowercase method - override:
     Error: Invalid number of arguments to Solidity function
      at Object.InvalidNumberOfSolidityArgs (/Users/leyboan1/.local/share/npm/lib/node_modules/truffle/build/webpack:/~/web3/lib/web3/errors.js:25:1)
      at SolidityFunction.validateArgs (/Users/leyboan1/.local/share/npm/lib/node_modules/truffle/build/webpack:/~/web3/lib/web3/function.js:74:1)
      at SolidityFunction.toPayload (/Users/leyboan1/.local/share/npm/lib/node_modules/truffle/build/webpack:/~/web3/lib/web3/function.js:90:1)
      at SolidityFunction.sendTransaction (/Users/leyboan1/.local/share/npm/lib/node_modules/truffle/build/webpack:/~/web3/lib/web3/function.js:163:1)
      at SolidityFunction.execute (/Users/leyboan1/.local/share/npm/lib/node_modules/truffle/build/webpack:/~/web3/lib/web3/function.js:256:1)
      at /Users/leyboan1/.local/share/npm/lib/node_modules/truffle/build/webpack:/~/truffle-contract/contract.js:202:1
      at /Users/leyboan1/.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)

  2) Contract: OverrideExample Test camelCase method - base:
     Error: Invalid number of arguments to Solidity function
      at Object.InvalidNumberOfSolidityArgs (/Users/leyboan1/.local/share/npm/lib/node_modules/truffle/build/webpack:/~/web3/lib/web3/errors.js:25:1)
      at SolidityFunction.validateArgs (/Users/leyboan1/.local/share/npm/lib/node_modules/truffle/build/webpack:/~/web3/lib/web3/function.js:74:1)
      at SolidityFunction.toPayload (/Users/leyboan1/.local/share/npm/lib/node_modules/truffle/build/webpack:/~/web3/lib/web3/function.js:90:1)
      at SolidityFunction.sendTransaction (/Users/leyboan1/.local/share/npm/lib/node_modules/truffle/build/webpack:/~/web3/lib/web3/function.js:163:1)
      at SolidityFunction.execute (/Users/leyboan1/.local/share/npm/lib/node_modules/truffle/build/webpack:/~/web3/lib/web3/function.js:256:1)
      at /Users/leyboan1/.local/share/npm/lib/node_modules/truffle/build/webpack:/~/truffle-contract/contract.js:202:1
      at /Users/leyboan1/.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)

Environment

• Operating System: Mac OSX
• Ethereum client: Ganache
• Truffle version (truffle version): 4.0.7
• node version (node --version): 7.7.3
• npm version (npm --version): 4.0.3

[mattlockyer]

This is the only thing that worked for me:

//this is the overloaded function, the original is safeTransferFrom['address,address,uint256']
const tx = await sampleNFT.contract.safeTransferFrom['address,address,uint256,bytes'](alice, composable.address, 1, "1", { from: alice, gas: 500000 });

[aleybovich]

Ok, I’ll keep an eye. You can close it as a duplicate. Thank you!