学习笔记：《Full Stack Blockchain Lesson 6：Hardhat Simple Storage》

Introduction

Hardhat Setup

• Hardhat Documentation

• DevDependencies vs Dependencies

• @ Sign node modules

Troubleshooting Hardhat Setup

• Special Guest Cami Ramos Garzon
Two common problems that you might see
• can’t get back the menu like this after installing hard hat and running the command npx hard hat in your new project folder



it usually just means that you have a config file somewhere that it shouldn't be, and deleting it will get rid of that error.

// 1.find the file
npx hardhat --verbose

// 2.delete the config file

// 3.recreate
npx harhat

 
• for getting to npm install

Hardhat Setup Continued

yarn hardhat

e.g. yarn hardhat [task]

AVAILABLE TASKS:

  check                 Check whatever you need
  clean                 Clears the cache and deletes all artifacts
  compile               Compiles the entire project, building all artifacts
  console               Opens a hardhat console
  coverage              Generates a code coverage report for tests
  flatten               Flattens and prints contracts and their dependencies
  gas-reporter:merge
  help                  Prints this message
  node                  Starts a JSON-RPC server on top of Hardhat Network
  run                   Runs a user-defined script after compiling the project
  test                  Runs mocha tests
  typechain             Generate Typechain typings for compiled contracts
  verify                Verifies contract on Etherscan

Deploying SimpleStorage from Hardhat

yarn hardhat compile

yarn add --dev prettier prettier-pulgin-solidity

// imports
const { ethers } = require("hardhat")

// async main
async function main() {
  const SimpleStorageFactory = await ethers.getContractFactory(
    "SimpleStorage"
  )
  console.log("Deploying contract...")
  const simpleStorage = await SimpleStorageFactory.deploy()
  await simpleStorage.deployed()
	// what's the private key?
	// what's the rpc url?
	console.log(`Deployed contract to:${simpleStorage.address}`)
}

// main
main().then(() => process.exit(0)).catch((error) => {
    console.error(error);
    process.exit(1);
})

Networks in Hardhat

• The Hardhat Network

• Hardhat configuration
hardhat have defaultNetwork.



 
add network sections that we want in hardhat.config.js.
1. add modules dotenv

yarn add --dev dotenv

2. create file named “.env” and edit it.

3. edit hardhat.config.js.

4. deploy contract with rinkeby.

// compile by rinkeby
yarn hardhat run scripts/deploy.js --network rinkeby

// compile by default
yarn hardhat run scripts/deploy.js // or yarn hardhat run scripts/deploy.js --network hardhat

• Chain ID List

Programmatic Verification

• Etherscan Verify Tutorial

• Etherscan Docs

• Hardhat-Etherscan

• Etherscan API Keys

• Javascript == vs ===

4 == "4" // true
4 === "4" // false

• Verify

Install hardhat-etherscan to make verification process much much easier.

npm install --savedev @nomiclabs/hardhat-etherscan

And add the following statement to hardhat.config.js file.

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

 

Add following Etherscan config to hardhat.config.js file.

module.exports = {
	networks: {
		mainnet: { ... }
	},
	etherscan: {
		// Your API key for Etherscan 
		// Obtain one at https://etherscan.io/
		appKey: "YOUR ETHERSCAN_ API KEY"
	}
};

 

Get api key for Etherscan.

Add api key in .env.

And add the following statement to hardhat.config.js file.

 

We‘ll get a new verify task.

programing verification.

Interacting with Contracts in Hardhat

Artifacts Troubleshooting

Custom Hardhat Tasks

• Hardhat Tasks

• Javascript Arrow Functions

• Custom block-number task
Create tasks folder, and create block-number.js file.



const { task } = require("hardhat/config")

task("block-number", "prints the current block number").setAction(
    // 
    async(taskArgs, hre) => {
        const blockNumber = await hre.ethers.provider.getBlockNumber()
        console.log(`Current block number:${blockNumber}`)
    }
)

 
Import block-number.js to hardhat.config.js .

require("./tasks/block-number")

 
excute command yarn hardhat , you will see the log following image.



 
Now you can use the task named block-number .

yarn hardhat block-number

Hardhat Localhost Node

Default Hardhat Network

hardhat node

# create new network everytime
yarn hardhat node

Custom local host

The Hardhat Console

• Hardhat Console
Execute following command to drop into a shell.

Hardhat Tests

• Hardhat Tests

• Mocha Style Tests

• Chai

• Waffle Tests

• Basic test
Create test folder and test-deploy.js file.

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

// describe("SimpleStorage", () => {})
describe("SimpleStorage", function () {
  // let simpleStorageFactory
  // let simpleStorage
  let simpleStorageFactory, simpleStorage
  beforeEach(async function () {
    simpleStorageFactory = await ethers.getContractFactory("SimpleStorage")
    simpleStorage = await simpleStorageFactory.deploy()
  })

  it("Should start with a favorite number of 0", async function () {
    const currentValue = await simpleStorage.retrieve()
    const expectedValue = "0"
    // assert
    // expect
    assert.equal(currentValue.toString(), expectedValue)
    // expect(currentValue.toString()).to.equal(expectedValue)
  })
  it("Should update when we call store", async function () {
    const expectedValue = "7"
    const transactionResponse = await simpleStorage.store(expectedValue)
    await transactionResponse.wait(1)

    const currentValue = await simpleStorage.retrieve()
    assert.equal(currentValue.toString(), expectedValue)
  })

  // Extra - this is not in the video
  it("Should work correctly with the people struct and array", async function () {
    const expectedPersonName = "Patrick"
    const expectedFavoriteNumber = "16"
    const transactionResponse = await simpleStorage.addPerson(
      expectedPersonName,
      expectedFavoriteNumber
    )
    await transactionResponse.wait(1)
    const { favoriteNumber, name } = await simpleStorage.people(0)
    // We could also do it like this
    // const person = await simpleStorage.people(0)
    // const favNumber = person.favoriteNumber
    // const pName = person.name

    assert.equal(name, expectedPersonName)
    assert.equal(favoriteNumber, expectedFavoriteNumber)
  })
})

Run test.

• Test seeing how much gas function cost
Install hardhat-gas-reporter , this is an extension that gets attached to all of our tests and automatically gives us an output that looks like this that tells us approximately how much gas each one of our functions cost.



# or yarn add hardhat- gas-reporter -dev
npm install hardhat-gas-reporter --save-dev

 
Add a new section called gas reporter to have it run whenever we run our test in hardhat.config.js .

require("hardhat-gas-reporter")

module.exports = {
	gasReporter: {
		enable: true,
	}	
}

 
Run following command, and then it will automatically run this gas reporter.

yarn hardhat test

Add outputFile in hardhat.config.js , Make it to output file. and then in .gitignored add the file.

require("hardhat-gas-reporter")

module.exports = {
	gasReporter: {
		enable: true,
		outputFile: "gasreport.txt",
		noColors: true, // the colors can get messed up basically when we output to a file
		currency: "USD", // get the cost of each function in usd
		coinmarketcap: "your coinmarketcap api key", // in order to get currency here
		token: "MATIC",
	}	
}

 

• Test covered
Install solidity-coverage, this is also a hardhat plugin that we can use for our code slowly, tests and sees how many lines of our .sol code is covered in a test.

yarn add --dev solidity-coverage

 
Import solidity-coverage to hardhat.config.js .

require("solidity-coverage")

 
Run following command to see coverage by default.

yarn hardhat coverage

Hardhat Gas Reporter

• Hardhat Gas Reporter

• Coinmarketcap API

Solidity Coverage

• Solidity Coverage

Hardhat Waffle

• Hardhat-Waffle

Lesson 6 Recap

Typescript Hardhat Simple Storage

• Typechain