Listen to Solidity Smart-Contract events using ethers.js and Hardhat

Events in solidity are the signals fired by smart-contract.

ethers.js has once function for listening to the emitted events.

The function takes two parameters:

1. eventName Name of the event. It should be a string.

2. listener It is the function. The task you are supposed to perform goes here.

Contract.once("eventName", listener)

Contract is the name of the Solidity Smart-Contract.

Here's an example for you using ethers.js in Hardhat development environment :

 async function mainFunc() {
    const contract = await ethers.getContract("ContractName", deployerAccount)
    await new Promise(async (resolve, reject) => {
        contract.once("NameOfTheEvent", () => {
            // perform your tasks here
            // & don't forget to resolve the promise
        })
    })
}