Created using remix-ide: Realtime Ethereum Contract Compiler and Runtime. Load this file by pasting this gists URL or ID at https://remix.ethereum.org/#version=soljson-v0.6.0-nightly.2019.3.11+commit.4704ef84.js&optimize=false&gist=

ballot.sol

pragma solidity >=0.4.22 <0.6.0;
contract Ballot {

    struct Voter {
        uint weight;
        bool voted;
        uint8 vote;
        address delegate;
    }
    struct Proposal {
        uint voteCount;
    }

    address chairperson;
    mapping(address => Voter) voters;
    Proposal[] proposals;

    /// Create a new ballot with $(_numProposals) different proposals.
    constructor(uint8 _numProposals) public {
        chairperson = msg.sender;
        voters[chairperson].weight = 1;
        proposals.length = _numProposals;
    }

    /// Give $(toVoter) the right to vote on this ballot.
    /// May only be called by $(chairperson).
    function giveRightToVote(address toVoter) public {
        if (msg.sender != chairperson || voters[toVoter].voted) return;
        voters[toVoter].weight = 1;
    }

    /// Delegate your vote to the voter $(to).
    function delegate(address to) public {
        Voter storage sender = voters[msg.sender]; // assigns reference
        if (sender.voted) return;
        while (voters[to].delegate != address(0) && voters[to].delegate != msg.sender)
            to = voters[to].delegate;
        if (to == msg.sender) return;
        sender.voted = true;
        sender.delegate = to;
        Voter storage delegateTo = voters[to];
        if (delegateTo.voted)
            proposals[delegateTo.vote].voteCount += sender.weight;
        else
            delegateTo.weight += sender.weight;
    }

    /// Give a single vote to proposal $(toProposal).
    function vote(uint8 toProposal) public {
        Voter storage sender = voters[msg.sender];
        if (sender.voted || toProposal >= proposals.length) return;
        sender.voted = true;
        sender.vote = toProposal;
        proposals[toProposal].voteCount += sender.weight;
    }

    function winningProposal() public view returns (uint8 _winningProposal) {
        uint256 winningVoteCount = 0;
        for (uint8 prop = 0; prop < proposals.length; prop++)
            if (proposals[prop].voteCount > winningVoteCount) {
                winningVoteCount = proposals[prop].voteCount;
                _winningProposal = prop;
            }
    }
}

ballot_test.sol

import "remix_tests.sol"; // this import is automatically injected by Remix.
import "./ballot.sol";

contract test3 {
   
    Ballot ballotToTest;
    function beforeAll () public {
       ballotToTest = new Ballot(2);
    }
    
    function checkWinningProposal () public {
        ballotToTest.vote(1);
        Assert.equal(ballotToTest.winningProposal(), uint(1), "1 should be the winning proposal");
    }
    
    function checkWinninProposalWithReturnValue () public view returns (bool) {
        return ballotToTest.winningProposal() == 1;
    }
}

scenario.json

{
  "accounts": {
    "account{0}": "0xca35b7d915458ef540ade6068dfe2f44e8fa733c"
  },
  "linkReferences": {},
  "transactions": [
    {
      "timestamp": 1557177841563,
      "record": {
        "value": "0",
        "parameters": [
          ""
        ],
        "abi": "0xc41589e7559804ea4a2080dad19d876a024ccb05117835447d72ce08c1d020ec",
        "contractName": "Ballot",
        "bytecode": "608060405234801561001057600080fd5b506040516020806108b28339810180604052602081101561003057600080fd5b8101908080519060200190929190505050336000806101000a81548173ffffffffffffffffffffffffffffffffffffffff021916908373ffffffffffffffffffffffffffffffffffffffff16021790555060018060008060009054906101000a900473ffffffffffffffffffffffffffffffffffffffff1673ffffffffffffffffffffffffffffffffffffffff1673ffffffffffffffffffffffffffffffffffffffff168152602001908152602001600020600001819055508060ff166002816100fa9190610101565b5050610154565b81548183558181111561012857818360005260206000209182019101610127919061012d565b5b505050565b61015191905b8082111561014d5760008082016000905550600101610133565b5090565b90565b61074f806101636000396000f3fe60806040526004361061005c576000357c0100000000000000000000000000000000000000000000000000000000900480635c19a95c14610061578063609ff1bd146100b25780639e7b8d61146100e3578063b3f98adc14610134575b600080fd5b34801561006d57600080fd5b506100b06004803603602081101561008457600080fd5b81019080803573ffffffffffffffffffffffffffffffffffffffff169060200190929190505050610172565b005b3480156100be57600080fd5b506100c76104c7565b604051808260ff1660ff16815260200191505060405180910390f35b3480156100ef57600080fd5b506101326004803603602081101561010657600080fd5b81019080803573ffffffffffffffffffffffffffffffffffffffff169060200190929190505050610543565b005b34801561014057600080fd5b506101706004803603602081101561015757600080fd5b81019080803560ff169060200190929190505050610640565b005b6000600160003373ffffffffffffffffffffffffffffffffffffffff1673ffffffffffffffffffffffffffffffffffffffff16815260200190815260200160002090508060010160009054906101000a900460ff16156101d257506104c4565b5b600073ffffffffffffffffffffffffffffffffffffffff16600160008473ffffffffffffffffffffffffffffffffffffffff1673ffffffffffffffffffffffffffffffffffffffff16815260200190815260200160002060010160029054906101000a900473ffffffffffffffffffffffffffffffffffffffff1673ffffffffffffffffffffffffffffffffffffffff161415801561030057503373ffffffffffffffffffffffffffffffffffffffff16600160008473ffffffffffffffffffffffffffffffffffffffff1673ffffffffffffffffffffffffffffffffffffffff16815260200190815260200160002060010160029054906101000a900473ffffffffffffffffffffffffffffffffffffffff1673ffffffffffffffffffffffffffffffffffffffff1614155b1561036f57600160008373ffffffffffffffffffffffffffffffffffffffff1673ffffffffffffffffffffffffffffffffffffffff16815260200190815260200160002060010160029054906101000a900473ffffffffffffffffffffffffffffffffffffffff1691506101d3565b3373ffffffffffffffffffffffffffffffffffffffff168273ffffffffffffffffffffffffffffffffffffffff1614156103a957506104c4565b60018160010160006101000a81548160ff021916908315150217905550818160010160026101000a81548173ffffffffffffffffffffffffffffffffffffffff021916908373ffffffffffffffffffffffffffffffffffffffff1602179055506000600160008473ffffffffffffffffffffffffffffffffffffffff1673ffffffffffffffffffffffffffffffffffffffff16815260200190815260200160002090508060010160009054906101000a900460ff16156104aa57816000015460028260010160019054906101000a900460ff1660ff1681548110151561048b57fe5b90600052602060002001600001600082825401925050819055506104c1565b816000015481600001600082825401925050819055505b50505b50565b6000806000905060008090505b6002805490508160ff16101561053e578160028260ff168154811015156104f757fe5b906000526020600020016000015411156105315760028160ff1681548110151561051d57fe5b906000526020600020016000015491508092505b80806001019150506104d4565b505090565b6000809054906101000a900473ffffffffffffffffffffffffffffffffffffffff1673ffffffffffffffffffffffffffffffffffffffff163373ffffffffffffffffffffffffffffffffffffffff161415806105eb5750600160008273ffffffffffffffffffffffffffffffffffffffff1673ffffffffffffffffffffffffffffffffffffffff16815260200190815260200160002060010160009054906101000a900460ff165b156105f55761063d565b60018060008373ffffffffffffffffffffffffffffffffffffffff1673ffffffffffffffffffffffffffffffffffffffff168152602001908152602001600020600001819055505b50565b6000600160003373ffffffffffffffffffffffffffffffffffffffff1673ffffffffffffffffffffffffffffffffffffffff16815260200190815260200160002090508060010160009054906101000a900460ff16806106a857506002805490508260ff1610155b156106b35750610720565b60018160010160006101000a81548160ff021916908315150217905550818160010160016101000a81548160ff021916908360ff160217905550806000015460028360ff1681548110151561070457fe5b9060005260206000200160000160008282540192505081905550505b5056fea165627a7a723058209061ffc04667804683fe01748db07db99f66b416464677c76a87e047d3ff2a430029",
        "linkReferences": {},
        "name": "",
        "inputs": "(uint8)",
        "type": "constructor",
        "from": "account{0}"
      }
    }
  ],
  "abis": {
    "0xc41589e7559804ea4a2080dad19d876a024ccb05117835447d72ce08c1d020ec": [
      {
        "constant": false,
        "inputs": [
          {
            "name": "to",
            "type": "address"
          }
        ],
        "name": "delegate",
        "outputs": [],
        "payable": false,
        "stateMutability": "nonpayable",
        "type": "function"
      },
      {
        "constant": false,
        "inputs": [
          {
            "name": "toVoter",
            "type": "address"
          }
        ],
        "name": "giveRightToVote",
        "outputs": [],
        "payable": false,
        "stateMutability": "nonpayable",
        "type": "function"
      },
      {
        "constant": false,
        "inputs": [
          {
            "name": "toProposal",
            "type": "uint8"
          }
        ],
        "name": "vote",
        "outputs": [],
        "payable": false,
        "stateMutability": "nonpayable",
        "type": "function"
      },
      {
        "inputs": [
          {
            "name": "_numProposals",
            "type": "uint8"
          }
        ],
        "payable": false,
        "stateMutability": "nonpayable",
        "type": "constructor"
      },
      {
        "constant": true,
        "inputs": [],
        "name": "winningProposal",
        "outputs": [
          {
            "name": "_winningProposal",
            "type": "uint8"
          }
        ],
        "payable": false,
        "stateMutability": "view",
        "type": "function"
      }
    ]
  }
}