Hardhat testing setup in Blockchain / Solidity - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to import the Hardhat testing helpers.

Blockchain / Solidity

const { [1] } = require("hardhat");

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Atruffle

Bweb3

Cganache

Dethers

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'web3' instead of 'ethers' causes errors because Hardhat uses ethers by default.

Trying to import 'truffle' or 'ganache' which are separate tools.

The ethers object is imported from Hardhat to interact with the Ethereum blockchain in tests.

2fill in blank

medium

Complete the code to get the list of signers for testing.

Blockchain / Solidity

const [owner, addr1] = await [1].getSigners();

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Aethers

Bweb3

Chardhat

Dnetwork

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'web3.getSigners()' which does not exist.

Trying to get signers from 'network' which is unrelated.

The ethers object provides the getSigners() method to get test accounts.

3fill in blank

hard

Fix the error in deploying the contract instance.

Blockchain / Solidity

const Contract = await ethers.getContractFactory("MyContract");
const contract = await Contract.[1]();

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Adeploy

Battach

Cconnect

Dcall

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'attach()' tries to connect to an existing contract, not deploy a new one.

Using 'connect()' or 'call()' which are not deployment methods.

The deploy() method creates a new contract instance on the blockchain.

4fill in blank

hard

Fill both blanks to write a test that checks the contract owner.

Blockchain / Solidity

describe("MyContract", function () {
  it("should set the right owner", async function () {
    const [[1]] = await ethers.getSigners();
    const Contract = await ethers.getContractFactory("MyContract");
    const contract = await Contract.deploy();
    await contract.deployed();
    expect(await contract.owner()).to.equal([2].address);
  });
});

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Aowner

Baddr1

Daddr2

Attempts:

3 left

💡 Hint

Common Mistakes

Using different variable names for the signer and the expected address causes test failures.

Using addresses of other signers like 'addr1' or 'addr2' incorrectly.

The first signer is usually called owner, and the test checks if the contract's owner matches owner.address.

5fill in blank

hard

Fill all three blanks to write a test that checks a function revert with a custom error message.

Blockchain / Solidity

it("should revert if not owner", async function () {
  const [owner, [1]] = await ethers.getSigners();
  const Contract = await ethers.getContractFactory("MyContract");
  const contract = await Contract.deploy();
  await contract.deployed();
  await expect(contract.connect([2]).restrictedFunction()).to.be.revertedWith([3]);
});

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Aaddr1

C"Ownable: caller is not the owner"

D"NotOwnerError"

Attempts:

3 left

💡 Hint

Common Mistakes

Using different signer variables for connecting and assigning.

Using incorrect or incomplete revert messages causing test failures.

The test uses addr1 as a non-owner signer and expects the revert message "Ownable: caller is not the owner".