Solidity: TypeError: Cannot read properties of undefined (reading 'JsonRpcProvider') in a simple HelloWorld contract by trying to test - testing

Question

I'm trying to test a simple HelloWorld.sol File:
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
contract HelloWorld
{
function hello() public pure returns (string memory)
{
return "Hello, World";
}
}
with a HelloWorld.ts testfile
import "#nomiclabs/hardhat-ethers" ;
import { ethers } from "hardhat";
import { expect } from "chai";
describe("hello world", function()
{
it("should say hello world", async function ()
{
const HelloWorld = await ethers.getContractFactory("HelloWorld");
const hello = await HelloWorld.deploy();
expect(hello).to.equal("Hello, World");
});
});
After calling: npx hardhat test
I got result with a error message:
hello world
1) should say hello world
0 passing (78ms)
1 failing
1) hello world
should say hello world:
TypeError: Cannot read properties of undefined (reading 'JsonRpcProvider')
at Object.<anonymous> (node_modules\#nomiclabs\hardhat-ethers\src\internal\ethers-provider-wrapper.ts:4:61)
at Module._compile (node:internal/modules/cjs/loader:1218:14)
at Module._extensions..js (node:internal/modules/cjs/loader:1272:10)
at Object.require.extensions.<computed> [as .js] (node_modules\ts-node\src\index.ts:1608:43)
at Module.load (node:internal/modules/cjs/loader:1081:32)
at Function.Module._load (node:internal/modules/cjs/loader:922:12)
at Module.require (node:internal/modules/cjs/loader:1105:19)
at require (node:internal/modules/cjs/helpers:103:18)
at Object.<anonymous> (node_modules\#nomiclabs\hardhat-ethers\src\internal\provider-proxy.ts:7:1)
at Module._compile (node:internal/modules/cjs/loader:1218:14)
I already did an internet research for answers/ fixing, but was not able to find an appropriate one..
So I don't know how to solve it and what am I supposed to do?
Thanks in advance!
please see above
Don't know why i get this error...

Answer 1

take a look at your contract instance, once you deploy the contract with
const hello = await HelloWorld.deploy();
You must call the hello() function to get the correct output.
Update your code with
describe("hello world", function()
{
it("should say hello world", async function ()
{
const HelloWorld = await ethers.getContractFactory("HelloWorld");
const helloWorldContract = await HelloWorld.deploy();
await helloWorldContract.deployed();
const hello = await helloWorldContract.hello();
expect(hello).to.be.equal("Hello, World");
});
});
You will notice that I also added the code await helloWorldContract.deployed(); this will wait until the deployment transaction is already on chain.
Good luck !

Answer 2

This error message is indicating that the JsonRpcProvider object is undefined. This error is likely being caused by an issue with the #nomiclabs/hardhat-ethers library.
A possible solution is to update the #nomiclabs/hardhat-ethers package to the latest version, as the issue may have been fixed in a newer version. You can do this by running the following command in your terminal:
npm install #nomiclabs/hardhat-ethers#latest
If updating the library doesn't resolve the issue, you could also try checking the documentation and example code provided by the library's creators, or reaching out to the library's support channels to ask for help.