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openzeppelin-contracts/test/token/ERC20/extensions/ERC20Burnable.test.js

105 lines
3.6 KiB

const { ethers } = require('hardhat');
const { expect } = require('chai');
const { loadFixture } = require('@nomicfoundation/hardhat-network-helpers');
const name = 'My Token';
const symbol = 'MTKN';
const initialBalance = 1000n;
async function fixture() {
const [owner, burner] = await ethers.getSigners();
const token = await ethers.deployContract('$ERC20Burnable', [name, symbol], owner);
await token.$_mint(owner, initialBalance);
return { owner, burner, token, initialBalance };
}
describe('ERC20Burnable', function () {
beforeEach(async function () {
Object.assign(this, await loadFixture(fixture));
});
describe('burn', function () {
it('reverts if not enough balance', async function () {
const value = this.initialBalance + 1n;
await expect(this.token.connect(this.owner).burn(value))
.to.be.revertedWithCustomError(this.token, 'ERC20InsufficientBalance')
.withArgs(this.owner, this.initialBalance, value);
});
describe('on success', function () {
for (const { title, value } of [
{ title: 'for a zero value', value: 0n },
{ title: 'for a non-zero value', value: 100n },
]) {
describe(title, function () {
beforeEach(async function () {
this.tx = await this.token.connect(this.owner).burn(value);
});
it('burns the requested value', async function () {
await expect(this.tx).to.changeTokenBalance(this.token, this.owner, -value);
});
it('emits a transfer event', async function () {
await expect(this.tx).to.emit(this.token, 'Transfer').withArgs(this.owner, ethers.ZeroAddress, value);
});
});
}
});
});
describe('burnFrom', function () {
describe('reverts', function () {
it('if not enough balance', async function () {
const value = this.initialBalance + 1n;
await this.token.connect(this.owner).approve(this.burner, value);
await expect(this.token.connect(this.burner).burnFrom(this.owner, value))
.to.be.revertedWithCustomError(this.token, 'ERC20InsufficientBalance')
.withArgs(this.owner, this.initialBalance, value);
});
it('if not enough allowance', async function () {
const allowance = 100n;
await this.token.connect(this.owner).approve(this.burner, allowance);
await expect(this.token.connect(this.burner).burnFrom(this.owner, allowance + 1n))
.to.be.revertedWithCustomError(this.token, 'ERC20InsufficientAllowance')
.withArgs(this.burner, allowance, allowance + 1n);
});
});
describe('on success', function () {
for (const { title, value } of [
{ title: 'for a zero value', value: 0n },
{ title: 'for a non-zero value', value: 100n },
]) {
describe(title, function () {
const originalAllowance = value * 3n;
beforeEach(async function () {
await this.token.connect(this.owner).approve(this.burner, originalAllowance);
this.tx = await this.token.connect(this.burner).burnFrom(this.owner, value);
});
it('burns the requested value', async function () {
await expect(this.tx).to.changeTokenBalance(this.token, this.owner, -value);
});
it('decrements allowance', async function () {
expect(await this.token.allowance(this.owner, this.burner)).to.equal(originalAllowance - value);
});
it('emits a transfer event', async function () {
await expect(this.tx).to.emit(this.token, 'Transfer').withArgs(this.owner, ethers.ZeroAddress, value);
});
});
}
});
});
});