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

117 lines
4.0 KiB

const { assertRevert } = require('../../helpers/assertRevert');
const expectEvent = require('../../helpers/expectEvent');
const BigNumber = web3.BigNumber;
const ZERO_ADDRESS = '0x0000000000000000000000000000000000000000';
require('chai')
.use(require('chai-bignumber')(BigNumber))
.should();
function shouldBehaveLikeERC20Burnable (owner, initialBalance, [burner]) {
describe('burn', function () {
describe('when the given amount is not greater than balance of the sender', function () {
context('for a zero amount', function () {
shouldBurn(0);
});
context('for a non-zero amount', function () {
shouldBurn(100);
});
function shouldBurn (amount) {
beforeEach(async function () {
({ logs: this.logs } = await this.token.burn(amount, { from: owner }));
});
it('burns the requested amount', async function () {
(await this.token.balanceOf(owner)).should.be.bignumber.equal(initialBalance - amount);
});
it('emits a burn event', async function () {
const event = expectEvent.inLogs(this.logs, 'TokensBurned');
event.args.burner.should.equal(owner);
event.args.value.should.be.bignumber.equal(amount);
});
it('emits a transfer event', async function () {
const event = expectEvent.inLogs(this.logs, 'Transfer');
event.args.from.should.equal(owner);
event.args.to.should.equal(ZERO_ADDRESS);
event.args.value.should.be.bignumber.equal(amount);
});
}
});
describe('when the given amount is greater than the balance of the sender', function () {
const amount = initialBalance + 1;
it('reverts', async function () {
await assertRevert(this.token.burn(amount, { from: owner }));
});
});
});
describe('burnFrom', function () {
describe('on success', function () {
context('for a zero amount', function () {
shouldBurnFrom(0);
});
context('for a non-zero amount', function () {
shouldBurnFrom(100);
});
function shouldBurnFrom (amount) {
const originalAllowance = amount * 3;
beforeEach(async function () {
await this.token.approve(burner, originalAllowance, { from: owner });
const { logs } = await this.token.burnFrom(owner, amount, { from: burner });
this.logs = logs;
});
it('burns the requested amount', async function () {
(await this.token.balanceOf(owner)).should.be.bignumber.equal(initialBalance - amount);
});
it('decrements allowance', async function () {
(await this.token.allowance(owner, burner)).should.be.bignumber.equal(originalAllowance - amount);
});
it('emits a burn event', async function () {
const event = expectEvent.inLogs(this.logs, 'TokensBurned');
event.args.burner.should.equal(owner);
event.args.value.should.be.bignumber.equal(amount);
});
it('emits a transfer event', async function () {
const event = expectEvent.inLogs(this.logs, 'Transfer');
event.args.from.should.equal(owner);
event.args.to.should.equal(ZERO_ADDRESS);
event.args.value.should.be.bignumber.equal(amount);
});
}
});
describe('when the given amount is greater than the balance of the sender', function () {
const amount = initialBalance + 1;
it('reverts', async function () {
await this.token.approve(burner, amount, { from: owner });
await assertRevert(this.token.burnFrom(owner, amount, { from: burner }));
});
});
describe('when the given amount is greater than the allowance', function () {
const amount = 100;
it('reverts', async function () {
await this.token.approve(burner, amount - 1, { from: owner });
await assertRevert(this.token.burnFrom(owner, amount, { from: burner }));
});
});
});
}
module.exports = {
shouldBehaveLikeERC20Burnable,
};