openzeppelin-contracts/test/token/ERC721/ERC721MintBurn.behavior.js

const { assertRevert } = require('../../helpers/assertRevert');
const expectEvent = require('../../helpers/expectEvent');
const BigNumber = web3.BigNumber;

require('chai')
  .use(require('chai-bignumber')(BigNumber))
  .should();

function shouldBehaveLikeMintAndBurnERC721 (
  creator,
  minter,
  [owner, newOwner, approved, anyone]
) {
  const firstTokenId = 1;
  const secondTokenId = 2;
  const thirdTokenId = 3;
  const unknownTokenId = 4;
  const ZERO_ADDRESS = '0x0000000000000000000000000000000000000000';
  const MOCK_URI = 'https://example.com';

  describe('like a mintable and burnable ERC721', function () {
    beforeEach(async function () {
      await this.token.mint(owner, firstTokenId, { from: minter });
      await this.token.mint(owner, secondTokenId, { from: minter });
    });

    describe('mint', function () {
      let logs = null;

      describe('when successful', function () {
        beforeEach(async function () {
          const result = await this.token.mint(newOwner, thirdTokenId, { from: minter });
          logs = result.logs;
        });

        it('assigns the token to the new owner', async function () {
          (await this.token.ownerOf(thirdTokenId)).should.be.equal(newOwner);
        });

        it('increases the balance of its owner', async function () {
          (await this.token.balanceOf(newOwner)).should.be.bignumber.equal(1);
        });

        it('emits a transfer and minted event', async function () {
          expectEvent.inLogs(logs, 'Transfer', {
            from: ZERO_ADDRESS,
            to: newOwner,
            tokenId: thirdTokenId,
          });
        });
      });

      describe('when the given owner address is the zero address', function () {
        it('reverts', async function () {
          await assertRevert(this.token.mint(ZERO_ADDRESS, thirdTokenId, { from: minter }));
        });
      });

      describe('when the given token ID was already tracked by this contract', function () {
        it('reverts', async function () {
          await assertRevert(this.token.mint(owner, firstTokenId, { from: minter }));
        });
      });
    });

    describe('mintWithTokenURI', function () {
      it('can mint with a tokenUri', async function () {
        await this.token.mintWithTokenURI(newOwner, thirdTokenId, MOCK_URI, {
          from: minter,
        });
      });
    });

    describe('burn', function () {
      const tokenId = firstTokenId;
      let logs = null;

      describe('when successful', function () {
        beforeEach(async function () {
          const result = await this.token.burn(tokenId, { from: owner });
          logs = result.logs;
        });

        it('burns the given token ID and adjusts the balance of the owner', async function () {
          await assertRevert(this.token.ownerOf(tokenId));
          (await this.token.balanceOf(owner)).should.be.bignumber.equal(1);
        });

        it('emits a burn event', async function () {
          expectEvent.inLogs(logs, 'Transfer', {
            from: owner,
            to: ZERO_ADDRESS,
            tokenId: tokenId,
          });
        });
      });

      describe('when there is a previous approval burned', function () {
        beforeEach(async function () {
          await this.token.approve(approved, tokenId, { from: owner });
          const result = await this.token.burn(tokenId, { from: owner });
          logs = result.logs;
        });

        context('getApproved', function () {
          it('reverts', async function () {
            await assertRevert(this.token.getApproved(tokenId));
          });
        });
      });

      describe('when the given token ID was not tracked by this contract', function () {
        it('reverts', async function () {
          await assertRevert(
            this.token.burn(unknownTokenId, { from: creator })
          );
        });
      });
    });
  });
}

module.exports = {
  shouldBehaveLikeMintAndBurnERC721,
};