ERC20Bridgable (ERC-7802) (#5735)

Co-authored-by: ernestognw <ernestognw@gmail.com>
Co-authored-by: Arr00 <13561405+arr00@users.noreply.github.com>

test/token/ERC20/extensions/draft-ERC20Bridgeable.test.js

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+const { ethers } = require('hardhat');
+const { expect } = require('chai');
+const { loadFixture } = require('@nomicfoundation/hardhat-network-helpers');
+
+const { shouldBehaveLikeERC20 } = require('../ERC20.behavior.js');
+const { shouldSupportInterfaces } = require('../../../utils/introspection/SupportsInterface.behavior');
+
+const name = 'My Token';
+const symbol = 'MTKN';
+const initialSupply = 100n;
+
+async function fixture() {
+  const [other, bridge, ...accounts] = await ethers.getSigners();
+
+  const token = await ethers.deployContract('$ERC20BridgeableMock', [name, symbol, bridge]);
+  await token.$_mint(accounts[0], initialSupply);
+
+  return { bridge, other, accounts, token };
+}
+
+describe('ERC20Bridgeable', function () {
+  beforeEach(async function () {
+    Object.assign(this, await loadFixture(fixture));
+  });
+
+  describe('onlyTokenBridgeFn', function () {
+    it('reverts when called by non-bridge', async function () {
+      await expect(this.token.onlyTokenBridgeFn()).to.be.revertedWithCustomError(this.token, 'OnlyTokenBridge');
+    });
+
+    it('does not revert when called by bridge', async function () {
+      await expect(this.token.connect(this.bridge).onlyTokenBridgeFn())
+        .to.emit(this.token, 'OnlyTokenBridgeFnCalled')
+        .withArgs(this.bridge);
+    });
+  });
+
+  describe('crosschainMint', function () {
+    it('reverts when called by non-bridge', async function () {
+      await expect(this.token.crosschainMint(this.other, 100n)).to.be.revertedWithCustomError(
+        this.token,
+        'OnlyTokenBridge',
+      );
+    });
+
+    it('mints amount provided by the bridge when calling crosschainMint', async function () {
+      const amount = 100n;
+      await expect(this.token.connect(this.bridge).crosschainMint(this.other, amount))
+        .to.emit(this.token, 'CrosschainMint')
+        .withArgs(this.other, amount, this.bridge)
+        .to.emit(this.token, 'Transfer')
+        .withArgs(ethers.ZeroAddress, this.other, amount);
+
+      await expect(this.token.balanceOf(this.other)).to.eventually.equal(amount);
+    });
+  });
+
+  describe('crosschainBurn', function () {
+    it('reverts when called by non-bridge', async function () {
+      await expect(this.token.crosschainBurn(this.other, 100n)).to.be.revertedWithCustomError(
+        this.token,
+        'OnlyTokenBridge',
+      );
+    });
+
+    it('burns amount provided by the bridge when calling crosschainBurn', async function () {
+      const amount = 100n;
+      await this.token.$_mint(this.other, amount);
+
+      await expect(this.token.connect(this.bridge).crosschainBurn(this.other, amount))
+        .to.emit(this.token, 'CrosschainBurn')
+        .withArgs(this.other, amount, this.bridge)
+        .to.emit(this.token, 'Transfer')
+        .withArgs(this.other, ethers.ZeroAddress, amount);
+
+      await expect(this.token.balanceOf(this.other)).to.eventually.equal(0);
+    });
+  });
+
+  describe('ERC165', function () {
+    shouldSupportInterfaces({
+      ERC7802: ['crosschainMint(address,uint256)', 'crosschainBurn(address,uint256)'],
+    });
+  });
+
+  describe('ERC20 behavior', function () {
+    shouldBehaveLikeERC20(initialSupply);
+  });
+});