Oasis Demo Quiz dApp

A confidential quiz dApp exposing the RNG to generate a random order of questions per coupon with the reward payout for the ones who solve it. Runs on Oasis Sapphire.

• backend contains the solidity contract, deployment and testing utils.
• frontend contains a Vue-based web application communicating with the backend smart contract.

This monorepo is set up for pnpm. Install dependencies by running:

pnpm install

Backend

Move to the backend folder and build smart contracts:

pnpm build

Next, deploy the contract.

Basic Local Hardhat Deployment

Start the hardhat node:

npx hardhat node

Deploy smart contracts to that local network:

npx hardhat deploy --network localhost

The deployed Quiz and NftReward addresses will be reported. Store them inside the frontend folder's .env.development, for example:

VITE_QUIZ_ADDR=0x385cAE1F3afFC50097Ca33f639184f00856928Ff

Deploying to Sapphire Localnet, Testnet and Mainnet

Prepare your hex-encoded private key and store it as an environment variable:

export PRIVATE_KEY=0x...

To deploy the Quiz and Reward contracts to the Sapphire Localnet, Testnet or Mainnet, use the following commands respectively:

npx hardhat deployQuiz --network sapphire-localnet
npx hardhat deployQuiz --network sapphire-testnet
npx hardhat deployQuiz --network sapphire

npx hardhat deployNftReward --network sapphire-localnet
npx hardhat deployNftReward --network sapphire-testnet
npx hardhat deployNftReward --network sapphire

Once deployed

Checklist after deploying a production-ready quiz:

1. Push questions. Example:

   npx hardhat addQuestions 0x385cAE1F3afFC50097Ca33f639184f00856928Ff test-questions.json --network sapphire-testnet

2. Add coupons. Example:

    hardhat addCoupons 0x385cAE1F3afFC50097Ca33f639184f00856928Ff test-coupons.txt  --network sapphire-testnet

3. Set ROSE payout reward amount. Example:

   npx hardhat setReward 0x385cAE1F3afFC50097Ca33f639184f00856928Ff 2.0  --network sapphire-testnet

4. Set gasless kaypair. The current account nonce will be fetched and stored to the contract. Because of that, the provided account must be used solely for gasless transactions by the deployed quiz contract. Example:

   npx hardhat setGaslessKeyPair 0x385cAE1F3afFC50097Ca33f639184f00856928Ff 0xd8cA6E05FC1a466992D98f5f4FFC621ca95b7229 0xbf63c1e7982a80f424b5e8c355b7f11a0968bf44b1407c473aadb364b8c291d3  --network sapphire-testnet

5. Fund the contract and the gasless account. Example:

   npx hardhat fund 0x385cAE1F3afFC50097Ca33f639184f00856928Ff 100  --network sapphire-testnet # contract
   npx hardhat fund 0xd8cA6E05FC1a466992D98f5f4FFC621ca95b7229 10  --network sapphire-testnet # gasless account

6. Set NFT reward contract address and enable Mint from Quiz contract.

   npx hardhat setNftAddress 0x385cAE1F3afFC50097Ca33f639184f00856928Ff  0xB22C255250d74B0ADD1bfB936676D2a299BF48Bd --network sapphire-testnet
   npx hardhat storeNFT 0xd8cA6E05FC1a466992D98f5f4FFC621ca95b7229 'test/assets/images/metadata_inline.json'   --network sapphire-testnet

7. Check the quiz contract status, to make sure if everything is set. Example:

   npx hardhat status 0x385cAE1F3afFC50097Ca33f639184f00856928Ff --network sapphire-testnet

   You can also obtain details on spent coupons as follows (may take a while):

   npx hardhat getCoupons 0x385cAE1F3afFC50097Ca33f639184f00856928Ff --network sapphire-testnet

Deploy and setup quiz with a single task

You can also setup and run the entire quiz in a single task. deployAndSetup deploys and sets up the quiz and NFT reward.

npx hardhat deployAndSetup test-config.yaml --network sapphire-testnet

Check out other hardhat tasks that will help you manage the quiz:

npx hardhat help

A note on tests:

When running tests on sapphire-localnet

npx hardhat test --network sapphire-localnet

avoid setting $PRIVATE_KEY environment variable, unless the address associated with this key is already funded on the network.

Additional tasks

1. Add single question.

npx hardhat addQuestion "My question?" 0x385cAE1F3afFC50097Ca33f639184f00856928Ff --network sapphire-testnet

2. Clear questions.

npx hardhat clearQuestions 0x385cAE1F3afFC50097Ca33f639184f00856928Ff --network sapphire-testnet

3. Reclaim funds from Quiz contract.

npx hardhat reclaimFunds 0x385cAE1F3afFC50097Ca33f639184f00856928Ff 0xC66AB83418C20A65C3f8e83B3d11c8C3a6097b6F --network sapphire-testnet

4. Fetch from Ipfs.

npx hardhat fetchImageFromIpfs Qmbr87zRx1uGM9fGYgHXRyq4EwSZ4jSaiXwQZC7ACpNcfW output.png

Frontend

After you compiled the backend, updated .env.development with the corresponding address and a chain ID, move to the frontend folder, compile and Hot-Reload frontend for Development:

pnpm dev

Navigate to http://localhost:5173 with your browser to view your dApp. Some browsers (e.g. Brave) may require https connection and a CA-signed certificate to access the wallet. In this case, read the section below on how to properly deploy your dApp.

You can use one of the deployed test accounts and associated private key with MetaMask. If you use the same MetaMask accounts on fresh local networks such as Hardhat Node, Foundry Anvil or sapphire-dev docker image, don't forget to clear your account's activity each time or manually specify the correct account nonce.

Frontend Deployment

You can build assets for deployment by running:

pnpm build

dist folder will contain the generated HTML files that can be hosted.

Different Website Base

If you are running dApp on a non-root base dir, add

BASE_DIR=/my/public/path

to .env.production and bundle the app with

pnpm build-only --base=/my/public/path/

Then copy the dist folder to a place of your /my/public/path location.