Reorganize the repo structure (#2503)

Co-authored-by: Francisco Giordano <frangio.1@gmail.com>

test/token/ERC20/extensions/draft-ERC20Permit.test.js

@@ -0,0 +1,117 @@
+/* eslint-disable */
+
+const { BN, constants, expectEvent, expectRevert, time } = require('@openzeppelin/test-helpers');
+const { expect } = require('chai');
+const { MAX_UINT256, ZERO_ADDRESS, ZERO_BYTES32 } = constants;
+
+const { fromRpcSig } = require('ethereumjs-util');
+const ethSigUtil = require('eth-sig-util');
+const Wallet = require('ethereumjs-wallet').default;
+
+const ERC20PermitMock = artifacts.require('ERC20PermitMock');
+
+const { EIP712Domain, domainSeparator } = require('../../../helpers/eip712');
+
+const Permit = [
+  { name: 'owner', type: 'address' },
+  { name: 'spender', type: 'address' },
+  { name: 'value', type: 'uint256' },
+  { name: 'nonce', type: 'uint256' },
+  { name: 'deadline', type: 'uint256' },
+];
+
+contract('ERC20Permit', function (accounts) {
+  const [ initialHolder, spender, recipient, other ] = accounts;
+
+  const name = 'My Token';
+  const symbol = 'MTKN';
+  const version = '1';
+
+  const initialSupply = new BN(100);
+
+  beforeEach(async function () {
+    this.token = await ERC20PermitMock.new(name, symbol, initialHolder, initialSupply);
+
+    // We get the chain id from the contract because Ganache (used for coverage) does not return the same chain id
+    // from within the EVM as from the JSON RPC interface.
+    // See https://github.com/trufflesuite/ganache-core/issues/515
+    this.chainId = await this.token.getChainId();
+  });
+
+  it('initial nonce is 0', async function () {
+    expect(await this.token.nonces(initialHolder)).to.be.bignumber.equal('0');
+  });
+
+  it('domain separator', async function () {
+    expect(
+      await this.token.DOMAIN_SEPARATOR(),
+    ).to.equal(
+      await domainSeparator(name, version, this.chainId, this.token.address),
+    );
+  });
+
+  describe('permit', function () {
+    const wallet = Wallet.generate();
+
+    const owner = wallet.getAddressString();
+    const value = new BN(42);
+    const nonce = 0;
+    const maxDeadline = MAX_UINT256;
+
+    const buildData = (chainId, verifyingContract, deadline = maxDeadline) => ({
+      primaryType: 'Permit',
+      types: { EIP712Domain, Permit },
+      domain: { name, version, chainId, verifyingContract },
+      message: { owner, spender, value, nonce, deadline },
+    });
+
+    it('accepts owner signature', async function () {
+      const data = buildData(this.chainId, this.token.address);
+      const signature = ethSigUtil.signTypedMessage(wallet.getPrivateKey(), { data });
+      const { v, r, s } = fromRpcSig(signature);
+
+      const receipt = await this.token.permit(owner, spender, value, maxDeadline, v, r, s);
+
+      expect(await this.token.nonces(owner)).to.be.bignumber.equal('1');
+      expect(await this.token.allowance(owner, spender)).to.be.bignumber.equal(value);
+    });
+
+    it('rejects reused signature', async function () {
+      const data = buildData(this.chainId, this.token.address);
+      const signature = ethSigUtil.signTypedMessage(wallet.getPrivateKey(), { data });
+      const { v, r, s } = fromRpcSig(signature);
+
+      await this.token.permit(owner, spender, value, maxDeadline, v, r, s);
+
+      await expectRevert(
+        this.token.permit(owner, spender, value, maxDeadline, v, r, s),
+        'ERC20Permit: invalid signature',
+      );
+    });
+
+    it('rejects other signature', async function () {
+      const otherWallet = Wallet.generate();
+      const data = buildData(this.chainId, this.token.address);
+      const signature = ethSigUtil.signTypedMessage(otherWallet.getPrivateKey(), { data });
+      const { v, r, s } = fromRpcSig(signature);
+
+      await expectRevert(
+        this.token.permit(owner, spender, value, maxDeadline, v, r, s),
+        'ERC20Permit: invalid signature',
+      );
+    });
+
+    it('rejects expired permit', async function () {
+      const deadline = (await time.latest()) - time.duration.weeks(1);
+
+      const data = buildData(this.chainId, this.token.address, deadline);
+      const signature = ethSigUtil.signTypedMessage(wallet.getPrivateKey(), { data });
+      const { v, r, s } = fromRpcSig(signature);
+
+      await expectRevert(
+        this.token.permit(owner, spender, value, deadline, v, r, s),
+        'ERC20Permit: expired deadline',
+      );
+    });
+  });
+});