NEAR enough - a wisdom of the crowd guessing game!

This README is for the front end React code. Check out the README in ./contract to learn more about the contract methods.

What is it?

NEAR enough is a personal project made to help me learn how to:

• build smart contracts in AssemblyScript
• expose contract methods through a front end
• transfer NEAR
• develop experience with NEAR

It was built for the NEAR bootcamp Jan 2021.

How is it made?

I started building the contract using near-sdk-as Starter Kit. After that I took some parts from a create-near-app to bootstrap a front end quickly. The whole thing was very fun.

What does it do?

It's a game where participants guess the weight of an animal. They pay 0.1 NEAR for the luxury. All guesses are stored and the average is calculated at the end of the game. The winner is the closest to the average, and receives all the money in the pool.

Todo

• I had problems with AssemblyScript number types. Specifically generating dates and random numbers. As a result I pass these values from JS to the contract (e.g. in makeGuess) as it was giving me less grief than doing it in AS, but I would like to refactor this in future.
• Currently starting and ending games is a manual process made by the contract owner. I would like this to be automated, e.g. games start and end at certain times every week. I have no idea how to do this.
• I'm not accounting for transaction fees properly in the end game when I transfer winnings to the winner. I need to investigate more how I should be covering costs.
• Add some kind of success messaging when a guess is successfully submitted.
• Convert JS to TS. Should have done this from the start but I was too eager to see things working.
• Write more contract unit tests, plus integ tests and UI tests.

Learnings

• I deployed to testnet server but GitHub thought it was mainline due to the config.js setup, so I amended according to this.
• JavaScript numbers and AssemblyScript numbers are totally different beasts and I still have a lot of work to do to get familiar with AS numbers.
• I am getting used to the development environent but so far I think this:
  • Having scripts run method calls seems more effort up front, but pays off in the long run to not have to write things out on the command line.
  • Think carefully up front about types in the contract model. Changing the types after already having items in storage may lead to a lot of type errors.

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The remainder of this README contains helpful setup notes from create-near-app.

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Quick Start

To run this project locally:

1. Prerequisites: Make sure you've installed Node.js ≥ 12
2. Install dependencies: yarn install and cd ./contract yarn install
3. Run the local development server: yarn dev (see package.json for a full list of scripts you can run with yarn)

Now you'll have a local development environment backed by the NEAR TestNet!

Go ahead and play with the app and the code. As you make code changes, the app will automatically reload.

Exploring The Code

1. The "backend" code lives in the /contract folder. See the README there for more info.
2. The frontend code lives in the /src folder. /src/index.html is a great place to start exploring. Note that it loads in /src/index.js, where you can learn how the frontend connects to the NEAR blockchain.
3. Tests: there are different kinds of tests for the frontend and the smart contract. See contract/README for info about how it's tested. The frontend code gets tested with jest. You can run both of these at once with yarn run test.

Deploy

Every smart contract in NEAR has its own associated account. When you run yarn dev, your smart contract gets deployed to the live NEAR TestNet with a throwaway account. When you're ready to make it permanent, here's how.

Step 0: Install near-cli (optional)

near-cli is a command line interface (CLI) for interacting with the NEAR blockchain. It was installed to the local node_modules folder when you ran yarn install, but for best ergonomics you may want to install it globally:

yarn install --global near-cli

Or, if you'd rather use the locally-installed version, you can prefix all near commands with npx

Ensure that it's installed with near --version (or npx near --version)

Step 1: Create an account for the contract

Each account on NEAR can have at most one contract deployed to it. If you've already created an account such as your-name.testnet, you can deploy your contract to near-enough.your-name.testnet. Assuming you've already created an account on NEAR Wallet, here's how to create near-enough.your-name.testnet:

1. Authorize NEAR CLI, following the commands it gives you:

   near login

2. Create a subaccount (replace YOUR-NAME below with your actual account name):

   near create-account near-enough.YOUR-NAME.testnet --masterAccount YOUR-NAME.testnet

Step 2: set contract name in code

Modify the line in src/config.js that sets the account name of the contract. Set it to the account id you used above.

const CONTRACT_NAME = process.env.CONTRACT_NAME || 'near-enough.YOUR-NAME.testnet'

Step 3: deploy!

One command:

yarn deploy

As you can see in package.json, this does two things:

1. builds & deploys smart contract to NEAR TestNet
2. builds & deploys frontend code to GitHub using gh-pages. This will only work if the project already has a repository set up on GitHub. Feel free to modify the deploy script in package.json to deploy elsewhere.