Web3.js Chainlink Plugin

This is a web3.js 4.x plugin for interacting with Chainlink Ethereum contracts.

Prerequisites

• ⚙️ NodeJS (LTS/Fermium)
• 🧰 Yarn

Installation

yarn add @chainsafe/web3.js-chainlink-plugin

Using this plugin

Installing Version 4.x of web3

When adding the web3 package to your project, make sure to use version 4.x:

• npm i -S [email protected]
• yarn add [email protected]

NOTE
If 4.x was already released, you are good to just use web3 without appending anything to it.

To verify you have the correct web3 version installed, after adding the package to your project (the above commands), look at the versions listed in your project's package.json under the dependencies section, it should contain version 4.x similar to:

"dependencies": {
	"web3": "4.0.3"
}

Registering the Plugin with a web3.js Instance

After importing ChainlinkPlugin from @chainsafe/web3-plugin-chainlink and Web3 from web3, register an instance of ChainlinkPlugin with an instance of Web3 like so:

import { ChainlinkPlugin } from '@chainsafe/web3-plugin-chainlink';
import { Web3 } from 'web3';

const web3 = new Web3('YOUR_PROVIDER_URL');
const chainlinkPlugin = new ChainlinkPlugin();

web3.registerPlugin(chainlinkPlugin);

More information about registering web3.js plugins can be found here.

Plugin Methods

Price Feed Addresses

Included in this plugin are two enums that contain the Ethereum contract addresses for specific token pairs: MainnetPriceFeeds and GoerliPriceFeeds. If you cannot find your desired price feed within these enums, please check here to make sure it's supported, and if it is, please open an issue or a pull request for the missing price feed so that it can be added to the appropriate enum.

getPrice

async getPrice(
		priceFeedAddress: MainnetPriceFeeds | GoerliPriceFeeds | Address,
		aggregatorInterfaceAbi: ContractAbi = defaultAggregatorInterfaceAbi,
	): {
        roundId: bigint,
        answer: bigint,
        startedAt: bigint,
        updatedAt: bigint,
        answeredInRound: bigint
    }

defaultAggregatorInterfaceAbi can be found here.

The getPrice method, accepts MainnetPriceFeeds | GoerliPriceFeeds | Address for it's first parameter, and an optional second parameter for specifying the Chainlink Aggregator Interface ABI of the Ethereum smart contract you'd like to interact with (the parameter is defaulted to defaultAggregatorInterfaceAbi).

Under the hood, this method is calling the latestRoundData for the specified price feed, more information about it can be found here.

import { ChainlinkPlugin, MainnetPriceFeeds } from '@chainsafe/web3-plugin-chainlink';
import { Web3 } from 'web3';

const web3 = new Web3('YOUR_PROVIDER_URL');
const chainlinkPlugin = new ChainlinkPlugin();

web3.registerPlugin(chainlinkPlugin);

web3.chainlink.getPrice(MainnetPriceFeeds.LinkEth).then(console.log);
// {
//     roundId: 73786976294838212867n,
//     answer: 4185000000000000n,
//     startedAt: 1674178043n,
//     updatedAt: 1674178043n,
//     answeredInRound: 73786976294838212867n
// }

Found an issue or have a question or suggestion

• ✍️ If you found an issue or have a question or suggestion submit an issue or join us on Discord

Run the tests

1. Clone the repo
2. Run yarn to install dependencies
   • If you receive the following warning, please remove the file package-lock.json and make sure to run yarn to install dependencies instead of npm i:

warning package-lock.json found. Your project contains lock files generated by tools other than Yarn. It is advised not to mix package managers in order to avoid resolution inconsistencies caused by unsynchronized lock files. To clear this warning, remove package-lock.json.

3. Run the tests:
   • yarn test:unit: Runs the mocked tests that do not make a network request using the Jest framework
   • End-to-end tests: Runs Webpack bundled tests that make a network request to the RPC provider https://rpc.ankr.com/eth and returns an actual response from MainnetPriceFeeds.LinkEth smart contract using the Cypress framework
     • yarn test:e2e:chrome: Runs the tests using Chrome
     • yarn test:e2e:electron: Runs the tests using Electron
     • yarn test:e2e:firefox: Runs the tests using Firefox
   • Black box tests: Uses a published version of the plugin from Verdaccio to run tests that make a network request to the RPC provider https://rpc.ankr.com/eth and returns an actual response from MainnetPriceFeeds.LinkEth smart contract using the Jest framework
     • NOTE The black box tests are setup to run within Github actions environment, but can be ran locally. The black_box_test_helpers.sh script can be used to:
       • start: Start Verdaccio using a Docker container
       • stop: Kill the Docker container
       • startBackgroundAndPublish: Starts a headless Docker container and publishes the plugin package
       • runTests: cds into the test/black_box directory, installs the black box package dependencies, and runs yarn test which will use Jest to run the tests
     • In addition to the black_box_test_helpers.sh script, the black box tests can be ran using the following package.json scripts:
       1. yarn pre-black-box: Calls startBackgroundAndPublish from the black_box_test_helpers.sh script
       2. yarn test:black-box: Calls yarn pre-black-box and runTests from the from the black_box_test_helpers.sh script
       3. yarn post-black-box: Calls stop from the black_box_test_helpers.sh script

Useful links

• web3.js Documentation
• Chainlink Documentation

Package.json Scripts

Script	Description
build	Uses tsc to build package and dependent packages
build:web	Uses webpack to build a browser ready build of the plugin in dist directory
clean	Uses rimraf to remove lib/ and dist/
format	Uses prettier to format the code
lint	Uses eslint to lint package
lint:fix	Uses eslint to check and fix any warnings
post-black-box	Uses stop from black_box_test_helpers.sh to kill running Verdaccio Docker container
pre-black-box	Uses startBackgroundAndPublish from black_box_test_helpers.sh to start a Verdaccio Docker container and publish the plugin package to it
prebuild	Calls yarn clean
prepare	Installs husky
test	Uses jest to run unit tests
test:black-box	Calls yarn pre-black-box and runTests from black_box_test_helpers.sh to run black box tests
test:coverage	Uses jest to report test coverage
test:e2e:chrome	Users cypress to run e2e test in a Chrome environment
test:e2e:firefox	Users cypress to run e2e test in a Firefox environment
test:e2e:electron	Users cypress to run e2e test in a Electron environment
test:unit	Uses jest to run tests under /test/unit