waffle.test.js

import { use, expect } from "chai";
import { solidity, createMockProvider, getWallets, deployContract } from 'ethereum-waffle'
import * as ERC20TokenJSON from '../build/ERC20Token.json'
import { ERC20Token } from '../typed-contracts/ERC20Token'

use(solidity);

describe('Counter smart contract', () => {
    const provider = createMockProvider();
    const [wallet] = getWallets(provider);

    async function deployToken(initialSupply: string): Promise<ERC20Token> {
        const token = await deployContract(wallet, ERC20TokenJSON, [initialSupply]) as ERC20Token;
        return token;
    }

    it('sets initial supply in the constructor', async () => {
        const token = await deployToken('100000000000000000000');
        const totalSupply = await token.totalSupply()
        expect(totalSupply).to.equal('100000000000000000000');
    });
});