Return variable named 'values' not available on the result object

[vanjan]

Given:

pragma solidity ^0.7.0;

contract ReturnValues {
  function getValues() public pure returns (uint8[3] memory values, uint8[3] memory dates) {
    values = [1, 2, 3];
    dates = [4, 5, 6];
    return (values, dates);
  }
}

I would expect this test to pass:

const { expect } = require('chai')

describe('ReturnValues', function () {
  let contract

  beforeEach(async function () {
    const ReturnValues = await ethers.getContractFactory('ReturnValues')
    contract = await ReturnValues.deploy()
    await contract.deployed()
  })

  it('should return object with keys "values" and "dates"', async function () {
    // when
    const result = await contract.getValues()

    // then
    expect(result).to.haveOwnProperty('values')
    expect(result).to.haveOwnProperty('dates')
  })
})

But it fails because the result object looks like this:

[ricmoo]

The result is an Array (with extra keys), and Result objects don’t overwrite properties defined on them (including on the prototype; this would break operations on them). So if a name collides with part of the Array prototype, those keys are dropped and must be accessed positionally.

If you adjust your signature you pass in though, you can resolve this, for example: ABI = [ "function getValues() pure returns (uint8[3] _values, uint8[3] dates)" ].

It looks like you are using Hardhat, (getContractFactory is something they inject; not part of ethers), so I’m not sure how to override the ABI but you could also re-instantiate the contract object via contract = new Contract(contract.address, aboveAbi, contract.signer || contract.provider).

Does that help?

[vanjan]

That makes sense, thank you. I had a feeling that's probably a reserved name and now I know why 👍🏻