CODEWITHSUNDEEP
javascriptethereumsoliditysmartcontractshardhat
sporejack
sporejack

Reputation: 101

Importing ethers via Hardhat fails despite official testing documentation

According to the official testing documentation for Hardhat, ethers should be available implicitly within the global scope; however, it can optionally be required explicitly, like so:

const { ethers } = require("hardhat");

This fails for my local project.

My package manifest seems to include the correct dependencies:

{
  "dependencies": {
    "@nomiclabs/hardhat-ethers": "^2.0.1",
    "@nomiclabs/hardhat-waffle": "^2.0.1",
    "@openzeppelin/contracts": "https://github.com/OpenZeppelin/openzeppelin-contracts#v4.0.0-beta.0",
    "chai": "^4.3.1",
    "hardhat": "^2.0.11"
  }
}

My unit tests file seems to match the worked example in the Hardhat documentation also:

const { ethers } = require("hardhat");
const { expect } = require("chai");

describe("Distributor.sol", function() {
    it("Distribution should fail for non-owners", async function() {
        const DistributorFactory = await ethers.getContractFactory("Distributor");
        const Distributor = await Distributor.deploy();

        Distributor.distribute([], []);

        expect(await hardhatToken.totalSupply()).to.be.revertedWith("foobar");
    });
});

Despite this, running the tests fails with:

$ yarn hardhat test
yarn run v1.22.5
$ /home/bob/dev/misc/token-distributor/node_modules/.bin/hardhat test


  Distributor.sol
undefined
    1) Distribution should fail for non-owners


  0 passing (9ms)
  1 failing

  1) Distributor.sol
       Distribution should fail for non-owners:
     TypeError: Cannot read property 'getContractFactory' of undefined
      at Context.<anonymous> (test/Distributor.js:8:49)
      at processImmediate (internal/timers.js:461:21)



error Command failed with exit code 1.
info Visit https://yarnpkg.com/en/docs/cli/run for documentation about this command.

How do I fix this?

Upvotes: 4

Views: 7438

Answers (4)

The-True-Hooha
The-True-Hooha

Reputation: 99

The above solution is now deprecated..

Use this instead: source https://hardhat.org/hardhat-runner/plugins/nomicfoundation-hardhat-ethers

npm install --save-dev @nomicfoundation/hardhat-ethers ethers

in your hardhat.config.js

require("@nomicfoundation/hardhat-ethers");

or hardhat.config.ts

import "@nomicfoundation/hardhat-ethers";

and you can now directly import in your test file

import { ethers } from "hardhat";

Upvotes: 0

C S
C S

Reputation: 1525

Two things:

  1. you need to install ethers separately too, as given in the instructions for hardhat-ethers, e.g.
    npm install --save-dev @nomiclabs/hardhat-ethers 'ethers@^5.0.0'

  2. Every Hardhat plugin needs to be registered in the Hardhat config file (hardhat.config.js):
    require("@nomiclabs/hardhat-ethers");

There is no need to remove the explicit import in your test file, however, Hardhat docs recommend following this style:

const hre = require("hardhat");
const { ethers } = hre;

Upvotes: 5

Priyanshu Jha
Priyanshu Jha

Reputation: 61

It still shows error, reading ethers undefined, I started the project all again with yarn hardhat and chose the first option "Create Simple Project" and it works perfectly.

Upvotes: 0

Patrick Collins
Patrick Collins

Reputation: 6131

Add the require in your hardhat.config.js

require("@nomiclabs/hardhat-waffle");

And remove this line from your test file:

const { ethers } = require("hardhat");

Then, you can use ethers in your tests. Hardhat looks in the config first before running tests. If you have required a package that includes ethers you can use it in the global scope.

Upvotes: 1

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