DappToke.js

const _deploy_contracts = require("../migrations/2_deploy_contracts")

var DappToken = artifacts.require('DappToken')

_deploy_contracts('DappToken', function(accounts)){
  it('sets the total supply upon deployment', function(){
    return DappToken deployed() 
  })
})

DappToken.sol

pragma solidity >=0.4.2;

contract DappToken{
  // Constructor
  // Set the Total number of tokens
  // Read the total number of tokens
  uint256 public totalSupply;

  constructor () public{
    totalSupply = 1000000;

  }
}