Remember that we promised to teach you how to deploy a smart contract?

It's been a while, but the time has come!

In this lesson, we will be teaching you how to deploy to Ethereum using Truffle.

And this is not all. You are going to learn how to deploy your smart contracts to Loom as well😎.

Why deploy to Loom? After all, Ethereum is the most secure network.

Yes, we totally agree with that. But on Ethereum each transaction costs gas, so your users will have to pay fees for each and every transaction. Also, they will have to wait at least 10 seconds for each transaction to be confirmed.

In a nutshell, on Ethereum, all transactions benefit from the same security guarantees. For something like a user-facing DApp or a game, this level of security isn't always a requirement. In fact, it just harms the user experience.

On Loom, users have access to much speedier and gas-free transactions. This makes Loom a much better fit for something like a game or a user-facing DApp.

Enough talking! Let's get started😉

Welcome! By completing the previous lessons you’ve demonstrated that you really know your stuff.

So, go ahead and deploy the game to the mainnet. Enjoy your success!

Hang on a moment... There are a few things you might have already thought of. After all, once contracts get deployed to the mainnet, they will live there forever. If there are mistakes in them, they will still live on as well. Like undead zombies.

Mistakes, or bugs, happen to every coder, no matter how skilled. It's unlikely that you would make a major mistake like giving attacking zombies a 100% chance of victory, but it could happen.

Clearly giving the attacking side 100% of wins would mean what you had written was no longer a game, or even any fun at all. A bug like this would kill your game dead, and no promise of juicy brains would drag your zombies from their graves.

To stop this terrible thing from happening, it is essential that you thoroughly test every aspect of the game.

By the end of this lesson, you will be able to:

• Test your smart contracts with Truffle against Ganache
• Use Chai to write more expressive assertions
• Test against Loom😉

Let's get started!

By completing the previous tutorials you've demonstrated a good grasp of Solidity and JavaScript; and you are probably well on your way to building your first dapp. If so, you may already have noticed that smart contracts can't directly access data from the outside world through an HTTP request or something similar. Instead, smart contracts pull data through something called an oracle.

This lesson is the first in the sequence of three lessons that aim to show how you can build and interact with an oracle.

In the first two lessons, we will be teaching you to build and interact with the simplest possible oracle that allows only one user, its owner, to fetch data from Binance's public API.

That said, I have a question for you: why would users trust your oracle?🤔🤔🤔

The quick answer is that they wouldn't. At least not until there social trust or you come up with a decentralized version. Thus, in the third lesson, we'll show you how to make your oracle more decentralized. But, for now, let's start with the beginning.

Time to write some code!

Now that you've got a bit of experience under your belt, we're going to dive into some of the more technical aspects of writing an oracle.

Remember that, even if you've covered a lot of ground, your oracle is still somehow centralized, meaning that only the owner is allowed to update the ETH price.

In this lesson, we'll show you how to make your oracle more decentralized.