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We will explore the basics of creating a Hardhat project with a sample contract, tests of that contract, and a script to deploy it.

To create the sample project, run npx hardhat in your project folder:

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👷 Welcome to Hardhat v2.9.9 👷‍

? What do you want to do? … ❯ Create a JavaScript project Create a TypeScript project Create an empty hardhat.config.js Quit Let’s create the JavaScript or TypeScript project and go through these steps to compile, test and deploy the sample contract. We recommend using TypeScript, but if you are not familiar with it just pick JavaScript.

#Running tasks To first get a quick sense of what's available and what's going on, run npx hardhat in your project folder:

$ npx hardhat Hardhat version 2.9.9

Usage: hardhat [GLOBAL OPTIONS] [TASK OPTIONS]

GLOBAL OPTIONS:

--config A Hardhat config file. --emoji Use emoji in messages. --help Shows this message, or a task's help if its name is provided --max-memory The maximum amount of memory that Hardhat can use. --network The network to connect to. --show-stack-traces Show stack traces. --tsconfig A TypeScript config file. --verbose Enables Hardhat verbose logging --version Shows hardhat's version.

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 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

To get help for a specific task run: npx hardhat help [task] The list of available tasks includes the built-in ones and also those that came with any installed plugins. npx hardhat is your starting point to find out what tasks are available to run.

#Compiling your contracts Next, if you take a look in the contracts/ folder, you'll see Lock.sol:

// SPDX-License-Identifier: UNLICENSED pragma solidity ^0.8.9;

// Import this file to use console.log import "hardhat/console.sol";

contract Lock { uint public unlockTime; address payable public owner;

event Withdrawal(uint amount, uint when);

constructor(uint _unlockTime) payable {
    require(
        block.timestamp < _unlockTime,
        "Unlock time should be in the future"
    );

    unlockTime = _unlockTime;
    owner = payable(msg.sender);
}

function withdraw() public {
    // Uncomment this line to print a log in your terminal
    // console.log("Unlock time is %o and block timestamp is %o", unlockTime, block.timestamp);

    require(block.timestamp >= unlockTime, "You can't withdraw yet");
    require(msg.sender == owner, "You aren't the owner");

    emit Withdrawal(address(this).balance, block.timestamp);

    owner.transfer(address(this).balance);
}

}

To compile it, simply run:

npx hardhat compile If you created a TypeScript project, this task will also generate TypeScript bindings using TypeChain.

#Testing your contracts Your project comes with tests that use Mocha, Chai, and Ethers.js.

If you take a look in the test/ folder, you'll see a test file: