When I try to test the contract with the following command:
```auto
npm test
```
I get the following Error:
```auto
Error: Error: socket hang up
...
Invalid JSON RPC response: ""
```
When trying to comment the specific test, I get the same error with the following error and so on.
I’ve tried also to remove describe and set a time out for jest:
```auto
jest.setTimeout(60 * 5 * 1000);
```
I get the same error.
I think it could be something related to a specific dependency, maybe inside the open zeppelin test environment?
Could you help me with that?
Thanks!
**💻 Environment**
openzeppelin/test-environment = v0.1.4
openzeppelin/test-helpers = v0.5.6
jest = v26.1.0
jest-matcher-utils = v26.1.0
openzeppelin/contracts v3.1.0
truffle = v5.1.35
**📝Details**
**🔢 Code to reproduce**
> **[naszam/wfil](https://github.com/naszam/wfil)**
>
> Wrapped Filecoin, Team WrapFS at HackFS @ETHGlobal - naszam/wfil
---
### Author:  [@abcoathup](https://forum.openzeppelin.com/u/abcoathup)
#### Post date: [July 23, 2020, 4:53am UTC](https://forum.openzeppelin.com/t/error-invalid-json-rpc-response-with-jest-and-openzeppelin-test-environment/3373/2 "2020-07-23T04:53:56Z")
Hi @naszam,
I’m sorry that you are having this issue.
I had exactly the same experience using your repository with Jest with `Invalid JSON RPC response: ""`.
I didn’t see anything obvious with your tests (though I am not familiar with Jest).
I converted the tests to use Mocha as the test runner and didn’t have any issues.
I even ran in parallel.
```auto
$ npx mocha --exit --recursive --parallel
WFIL
✓ the deployer is the owner
✓ owner has the default admin role (68ms)
✓ owner has the minter role (42ms)
✓ owner has the pauser role (43ms)
✓ minter and pauser role admin is the default admin
minting
✓ owner can mint tokens (57ms)
✓ other accounts cannot mint tokens (93ms)
pausing
✓ owner can pause (65ms)
✓ owner can unpause (105ms)
✓ cannot mint while paused (82ms)
✓ other accounts cannot pause (43ms)
burning
✓ holders can burn their tokens (112ms)
12 passing (3s)
```
Test converted to be used with mocha
```auto
// based on https://github.com/OpenZeppelin/openzeppelin-contracts/blob/master/test/presets/ERC20PresetMinterPauser.test.js
// test/WFIL.test.js
const { accounts, contract, web3 } = require('@openzeppelin/test-environment');
const { BN, constants, expectEvent, expectRevert } = require('@openzeppelin/test-helpers');
const { ZERO_ADDRESS } = constants;
const { expect } = require('chai');
const WFIL = contract.fromArtifact('WFIL');
let wfil;
describe('WFIL', function () {
const [owner, other] = accounts;
const name = 'Wrapped Filecoin';
const symbol = 'WFIL';
const amount = new BN('5000');
const DEFAULT_ADMIN_ROLE = '0x0000000000000000000000000000000000000000000000000000000000000000';
const MINTER_ROLE = web3.utils.soliditySha3('MINTER_ROLE');
const PAUSER_ROLE = web3.utils.soliditySha3('PAUSER_ROLE');
beforeEach(async function () {
wfil = await WFIL.new({ from: owner })
});
it('the deployer is the owner', async function () {
expect(await wfil.owner()).to.equal(owner);
});
it('owner has the default admin role', async function () {
expect(await wfil.getRoleMemberCount(DEFAULT_ADMIN_ROLE)).to.be.bignumber.equal(new BN(1));
expect(await wfil.getRoleMember(DEFAULT_ADMIN_ROLE, 0)).to.equal(owner);
});
it('owner has the minter role', async function () {
expect(await wfil.getRoleMemberCount(MINTER_ROLE)).to.be.bignumber.equal(new BN(1));
expect(await wfil.getRoleMember(MINTER_ROLE, 0)).to.equal(owner);
});
it('owner has the pauser role', async function () {
expect(await wfil.getRoleMemberCount(PAUSER_ROLE)).to.be.bignumber.equal(new BN(1));
expect(await wfil.getRoleMember(PAUSER_ROLE, 0)).to.equal(owner);
});
it('minter and pauser role admin is the default admin', async function () {
expect(await wfil.getRoleAdmin(MINTER_ROLE)).to.equal(DEFAULT_ADMIN_ROLE);
expect(await wfil.getRoleAdmin(PAUSER_ROLE)).to.equal(DEFAULT_ADMIN_ROLE);
});
describe('minting', function () {
it('owner can mint tokens', async function () {
const receipt = await wfil.mint(other, amount, { from: owner });
expectEvent(receipt, 'Transfer', { from: ZERO_ADDRESS, to: other, value: amount });
expect(await wfil.balanceOf(other)).to.be.bignumber.equal(amount);
});
it('other accounts cannot mint tokens', async function () {
await expectRevert(wfil.mint(other, amount, { from: other }),'WFIL: must have minter role to mint');
});
});
describe('pausing', function () {
it('owner can pause', async function () {
const receipt = await wfil.pause({ from: owner });
expectEvent(receipt, 'Paused', { account: owner });
expect(await wfil.paused()).to.equal(true);
});
it('owner can unpause', async function () {
await wfil.pause({ from: owner });
const receipt = await wfil.unpause({ from: owner });
expectEvent(receipt, 'Unpaused', { account: owner });
expect(await wfil.paused()).to.equal(false);
});
it('cannot mint while paused', async function () {
await wfil.pause({ from: owner });
await expectRevert(
wfil.mint(other, amount, { from: owner }),
'ERC20Pausable: token transfer while paused'
);
});
it('other accounts cannot pause', async function () {
await expectRevert(wfil.pause({ from: other }), 'WFIL: must have pauser role to pause');
});
});
describe('burning', function () {
it('holders can burn their tokens', async function () {
await wfil.mint(other, amount, { from: owner });
const receipt = await wfil.burn(amount.subn(1), { from: other });
expectEvent(receipt, 'Transfer', { from: other, to: ZERO_ADDRESS, value: amount.subn(1) });
expect(await wfil.balanceOf(other)).to.be.bignumber.equal(new BN(1));
});
});
});
```
I reproduced using a test cloned from OpenZeppelin Contracts and created an Issue: [https://github.com/OpenZeppelin/openzeppelin-test-environment/issues/130](https://github.com/OpenZeppelin/openzeppelin-test-environment/issues/130)
As a work around I suggest using Mocha as your test runner.
---
### Author:  [@naszam](https://forum.openzeppelin.com/u/naszam)
#### Post date: [July 23, 2020, 9:55am UTC](https://forum.openzeppelin.com/t/error-invalid-json-rpc-response-with-jest-and-openzeppelin-test-environment/3373/3 "2020-07-23T09:55:23Z")
I will migrate to mocha for now.
Anyway, I’m curious to see what is causing the issue.
Thanks!
---
### Author:  [@abcoathup](https://forum.openzeppelin.com/u/abcoathup)
#### Post date: [July 24, 2020, 6:11am UTC](https://forum.openzeppelin.com/t/error-invalid-json-rpc-response-with-jest-and-openzeppelin-test-environment/3373/4 "2020-07-24T06:11:06Z")
Hi @naszam,
I tested using an integration test and `jest@24.9.0` works but `jest@25.0.0` fails
>
>
> Using Jest as the test runner, test fails with Error: socket hang up
> Reported in the community forum: https://forum.openzeppelin.com/t/error-invalid-json-rpc-response-when-testing-erc20-token-based-on-preset-with-jest-and-openzeppelin-test-environment/3373
> I can reproduce with...
As a work around you could try using `jest@24.9.0` otherwise use mocha.
---
### Author:  [@naszam](https://forum.openzeppelin.com/u/naszam)
#### Post date: [July 24, 2020, 11:46am UTC](https://forum.openzeppelin.com/t/error-invalid-json-rpc-response-with-jest-and-openzeppelin-test-environment/3373/5 "2020-07-24T11:46:05Z")
Oh! Ok. Thanks!
I’ll stick with mocha (in parallel) for now.
Thanks!
---
### Author:  [@PradhumnaPancholi](https://forum.openzeppelin.com/u/PradhumnaPancholi)
#### Post date: [March 14, 2022, 8:45pm UTC](https://forum.openzeppelin.com/t/error-invalid-json-rpc-response-with-jest-and-openzeppelin-test-environment/3373/6 "2022-03-14T20:45:09Z")
Got bumped into the same error. I am using Mocha though
```auto
it("General user can not pause the contract", async function () {
await expectRevert(
contract.connect(addr1).pause(),
"Ownable: caller is not the owner"
);
expect(await contract.paused()).to.equal(false);
});
```
I don't see anything obvious here.