This is a test for the issue: [artifacts-require-refundescrow](https://forum.openzeppelin.com/t/artifacts-require-refundescrow/6784/12) in the OpenZeppelin Forum

package.json

{
  "name": "topic_6784",
  "version": "1.0.0",
  "main": "index.js",
  "license": "MIT",
  "dependencies": {
    "@openzeppelin/contracts": "2.5.1",
    "truffle": "^5.3.6"
  }
}

PFBTokenCrowdsale.sol

pragma solidity >=0.5.1;

import "@openzeppelin/contracts/token/ERC20/ERC20.sol";
import "@openzeppelin/contracts/token/ERC20/ERC20Mintable.sol";
import "@openzeppelin/contracts/token/ERC20/ERC20Pausable.sol";
import "@openzeppelin/contracts/crowdsale/Crowdsale.sol";
import "@openzeppelin/contracts/crowdsale/emission/MintedCrowdsale.sol";
import "@openzeppelin/contracts/crowdsale/validation/CappedCrowdsale.sol";
import "@openzeppelin/contracts/crowdsale/validation/WhitelistCrowdsale.sol";
import "@openzeppelin/contracts/crowdsale/distribution/RefundableCrowdsale.sol";

contract PFBTokenCrowdsale is
    Crowdsale,
    MintedCrowdsale,
    CappedCrowdsale,
    WhitelistCrowdsale,
    RefundableCrowdsale
{
    // Track investor contributions
    uint256 public investorMinCap = 10000000000000000; // 0.01 ether
    uint256 public investorHardCap = 350000000000000000000; // 350 ether
    mapping(address => uint256) public contributions;

    constructor(
        uint256 _rate,
        address payable _wallet,
        ERC20 _token,
        uint256 _cap,
        uint256 _goal
    )
        public
        Crowdsale(_rate, _wallet, _token)
        CappedCrowdsale(_cap)
        RefundableCrowdsale(_goal)
    {
        require(_goal <= _cap);
    }

    /**
     * @dev Returns the amount contributed so far by a sepecific user.
     * @param _beneficiary Address of contributor
     * @return User contribution so far
     */
    function getUserContribution(address _beneficiary)
        public
        view
        returns (uint256)
    {
        return contributions[_beneficiary];
    }

    /**
     * @dev Extend parent behavior requiring purchase to respect investor min/max funding cap.
     * @param _beneficiary Token purchaser
     * @param _weiAmount Amount of wei contributed
     */
    function _preValidatePurchase(address _beneficiary, uint256 _weiAmount)
        internal
        view
    {
        super._preValidatePurchase(_beneficiary, _weiAmount);
        uint256 _existingContribution = contributions[_beneficiary];
        uint256 _newContribution = _existingContribution.add(_weiAmount);
        require(
            _newContribution <= investorHardCap,
            "The maximum investment amount is: 350 ether"
        );
        require(
            _newContribution >= investorMinCap,
            "The minimum investment amount is: 0.01 ether"
        );
    }

    /**
     * @dev Extend parent behavior to update beneficiary contributions.
     * @param beneficiary Token purchaser
     * @param weiAmount Amount of wei contributed
     */
    function _updatePurchasingState(address beneficiary, uint256 weiAmount)
        internal
    {
        super._updatePurchasingState(beneficiary, weiAmount);
        contributions[beneficiary] = contributions[beneficiary].add(weiAmount);
    }
}

result.md

Result is at here:

testPFBTokenCrowdsale.js

const RefundEscrow = artifacts.require('RefundEscrow');


contract('MyTokenCrowdsale', function ([_, wallet, investor1, investor2]) {
    console.log("no error!");
});