Balance / Value testing
// requirement: truffle-assertions
// install: npm install truffle-assertions
// usage: const truffleAssert = require('truffle-assertions');
// Tests:
// Check contract handles values correctly
// - When createPerson(), balance increases and increases correctly
// - Must match the new correct balance of the contract address on the blockchain
// - Check the owner can withdraw the balance
// - Check the balance is reduced to 0
// - Check the owner wallet address is updated correctly on the blockchain
// Helpers
// web3.eth.getBalance(address)
// get the contract address from instance.address
// Functions tested:
// function createPerson(string memory name, uint age, uint height) public payable costs(1 ether)
// function withdrawAll() public onlyOwner returns(uint) {
const People = artifacts.require("People");
const truffleAssert = require('truffle-assertions');
contract("People", async function(accounts) {
let instance;
let contractPreBalance;
let contractPostBalance;
let ownerPreWithdrawl;
let ownerPostWithdrawl;
// before() runs once before anythign else
before(async function() {
instance = await People.deployed();
});
it("Check contract balances are increased correctly when creating a person.", async function() {
contractPreBalance = await web3.eth.getBalance(instance.address);
//console.log(" > > Balance pre creation: " + contractPreBalance);
await instance.createPerson("Person 1", 35, 170, {from: accounts[1], value: web3.utils.toWei("1", "ether")});
contractPostBalance = await web3.eth.getBalance(instance.address);
//console.log(" > > Balance post creation: " + contractPostBalance);
await truffleAssert.passes(contractPostBalance === contractPreBalance + web3.utils.toWei("1", "ether"));
await truffleAssert.passes(instance.balance === contractPostBalance);
});
it("Ensure non-owners cannot withdrawAll().", async function() {
await truffleAssert.fails(instance.withdrawAll({from: accounts[1]}), truffleAssert.ErrorType.REVERT);
});
it("Check contract balance is zeroed and owner balance is increased correctly when withdrawing.", async function() {
contractPreBalance = await web3.eth.getBalance(instance.address);
ownerPreWithdrawl = await web3.eth.getBalance(accounts[0]);
//console.log(" > > Contract balance pre creation: " + contractPreBalance);
//console.log(" > > Owner balance pre creation: " + ownerPreWithdrawl);
await instance.withdrawAll({from: accounts[0]});
contractPostBalance = await web3.eth.getBalance(instance.address);
ownerPostWithdrawl = await web3.eth.getBalance(accounts[0]);
//console.log(" > > Contract balance post withdrawl: " + contractPostBalance);
//console.log(" > > Owner balance post withdrawl: " + ownerPostWithdrawl);
await truffleAssert.passes(contractPostBalance === 0);
await truffleAssert.passes(ownerPostWithdrawl > ownerPreWithdrawl);
});
});```
