Master Ethereum Development: From Beginner to Dapp Developer/

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Testing the Auction Smart Contract

Testing the Auction Smart Contract

Learn how to write advanced tests using the Truffle Framework, and implement tests for the Auction smart contract

We'll cover the following...

In this lesson, we'll dive deeper into writing unit tests with Truffle and practice our new skills by writing tests for the Auction contract. This contract is more complex and will allow us to learn how to write more advanced tests.

Initialize the contract

To create tests for the new contract, we'll add another test file called auction.js in the tests.

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test
├── auction.js
└── ownable.js

There are no requirements to have different files to test different contracts, but this separation would make it easier to work with those tests.

To test the Auction contract, we'll have a slightly more complex setup. For each auction, we first need to create an Ownable instance, and then create an Auction instance using it. To do this, we begin by defining two variables, one for the Ownable contract instance and another for the Auction contract. We then initialize both of them in the beforeEach method.

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const Ownable = artifacts.require('Ownable')
const Auction = artifacts.require('Auction')
contract('Auction', function (accounts) {
  let ownable
  let auction
  const beneficiary = accounts[0]
  beforeEach(async function () {
    ownable = await Ownable.new('ticket', { from: beneficiary })
    auction = await Auction.new(ownable.address, { from: beneficiary })
  })
  ...
})

We also arbitrarily select the first account in the accounts list as the auction’s beneficiary.

Testing errors

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