solidity.io code challange

Simple nestjs app that uses ethers.js to interact with a smart contract.

It listens to events coming from the smart contract and forwards them through the websocket.

Requirements

In order to run this app you need to have to deploy smart contract to a testnet and have the address of the deployed contract.

How to do that can be found in util/smart-contract/README.md.

Configuration

To configure server which smart contract to listen to, you need to configure the following environment variables:

WALLET_PRIVATE_KEY=
NODE_RPC_URL=

After that you need to add smart contract config in smart-contracts-events-config service.

{
  name: 'SimpleStorage2',
  address: '0x0d4b13ab292c7E6A43f9616f6beFD39Be1a569eD',
  rpc_url: this.configService.get<string>('NODE_RPC_URL'),
  wallet_pk: this.configService.get<string>('WALLET_PRIVATE_KEY'),
  abi: SimpleStorageAbi.abi,
  events: ['DataChanged'],
}

Running the app

First install node modules:

$ yarn install

# development
$ yarn run start

# watch mode
$ yarn run start:dev

# production mode
$ yarn run start:prod

Test websocket

To test websocket simpler I've created a simple html page that connects to the websocket and logs the events.

To test it, open util/ws-test.html in your browser. New data will appear in the console.

Test smart contract

To trigger an event on the smart contract after running the app, you can use the following endpoint: http://localhost:3000/smart-contracts-events/trigger-events

It will call set on all smart contracts and which trigger the event. I know it's not the best approach, but it's just for testing purposes.

Test

# unit tests
$ yarn run test

# e2e tests
$ yarn run test:e2e

# test coverage
$ yarn run test:cov