02.md

title	actions	requireLogin	material
Getting Started with Truffle	checkAnswer hints	true	terminal help commands First, you should probably run `truffle init`. Next, execute `npm install truffle-hdwallet-provider` truffle init npm install truffle-hdwallet-provider hint output truffle init Downloading... Unpacking... Setting up... Unbox successful. Sweet! Commands: Compile: truffle compile Migrate: truffle migrate Test contracts: truffle test hint output npm install truffle-hdwallet-provider + [email protected] added 1 package from 1 contributor and audited 71402 packages in 5.612s found 0 vulnerabilities

Now that we've installed Truffle, it's time to initialize our new project by running truffle init. All it is doing is to create a set of folders and config files with the following structure:

├── contracts
    ├── Migrations.sol
├── migrations
    ├── 1_initial_migration.js
└── test
truffle-config.js
truffle.js

Contracts, migrations, tests... this is pretty complicated😟

Don't worry, learning to use Truffle won't eat your brains. This chapter will walk you through Truffle's default project structure, and once you know how to use Truffle, deploying smart contracts will be a breeze.

Truffle's Default Directory Structure

So, running the truffle init command inside of the CryptoZombies directory, should create several directories and some JavaScript and Solidity files. Let's have a closer look:

• contracts: this is the place where Truffle expects to find all our smart contracts. To keep the code organized, we can even create nested folders such as contracts/tokens. Pretty neat😉.

Note: truffle init should automatically create a contract called Migrations.sol and the corresponding migration file. We'll explain them a bit later.

• migrations: a migration is a JavaScript file that tells Truffle how to deploy a smart contract.

• test: here we are expected to put the unit tests which will be JavaScript or Solidity files. Remember, once a contract is deployed it can't be changed, making it essential that we test our smart contracts before we deploy them.

• truffle.js and truffle-config.js: config files used to store the network settings for deployment. Truffle needs two config files because on Windows having both truffle.js and truffle.exe in the same folder might generate conflicts. Long story short - if you are running Windows, it is advised to delete truffle.js and use truffle-config.js as the default config file. Check out Truffle's official documentation to further your understanding.

But why should I use this directory structure? I'm not used to it and it looks complicated...

Well, there's are a few good reasons. First, Truffle will not work as expected if you change the names of these folders.

Second, by adhering to this convention your projects will be easily understood by other developers. To put it short, using a standard folder structures and code conventions make it easier if you expand or change your team in the future.

truffle-hdwallet-provider

In this lesson, we will be using Infura to deploy our code to Ethereum. This way, we can run the application without needing to set up our own Ethereum node or wallet. However, to keep things secure, Infura does not manage the private keys, which means it can't sign transactions on our behalf. Since deploying a smart contract requires Truffle to sign transactions, we are going to need a tool called truffle-hdwallet-provider. Its only purpose is to handle the transaction signing.

Note: Maybe you are asking why we chose not to install truffle-hdwallet-provider in the previous chapter using something like:

npm install truffle truffle-hdwallet-provider

Well... the truffle init command expects to find an empty directory. If there's any file there, it will error out. Thus, we need to do everything in the correct order and install truffle-hdwallet-provider after we run truffle init.

Put it to the test:

1. Run truffle init. This command generates the directory structure that we've discussed.

2. Run npm install truffle-hdwallet-provider.