Implement UUPS proxy (ERC1822) (#2542)

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

test/proxy/UUPS/UUPSUpgradeable.test.js

@@ -0,0 +1,72 @@
+const { expectEvent, expectRevert } = require('@openzeppelin/test-helpers');
+
+const ERC1967Proxy = artifacts.require('ERC1967Proxy');
+const UUPSUpgradeableMock = artifacts.require('UUPSUpgradeableMock');
+const UUPSUpgradeableUnsafeMock = artifacts.require('UUPSUpgradeableUnsafeMock');
+const UUPSUpgradeableBrokenMock = artifacts.require('UUPSUpgradeableBrokenMock');
+const CountersImpl = artifacts.require('CountersImpl');
+
+contract('UUPSUpgradeable', function (accounts) {
+  before(async function () {
+    this.implInitial = await UUPSUpgradeableMock.new();
+    this.implUpgradeOk = await UUPSUpgradeableMock.new();
+    this.implUpgradeUnsafe = await UUPSUpgradeableUnsafeMock.new();
+    this.implUpgradeBroken = await UUPSUpgradeableBrokenMock.new();
+    this.implUpgradeNonUUPS = await CountersImpl.new();
+  });
+
+  beforeEach(async function () {
+    const { address } = await ERC1967Proxy.new(this.implInitial.address, '0x');
+    this.instance = await UUPSUpgradeableMock.at(address);
+  });
+
+  it('upgrade to upgradeable implementation', async function () {
+    const { receipt } = await this.instance.upgradeTo(this.implUpgradeOk.address);
+    expect(receipt.logs.filter(({ event }) => event === 'Upgraded').length).to.be.equal(1);
+    expectEvent(receipt, 'Upgraded', { implementation: this.implUpgradeOk.address });
+  });
+
+  it('upgrade to upgradeable implementation with call', async function () {
+    expect(await this.instance.current()).to.be.bignumber.equal('0');
+
+    const { receipt } = await this.instance.upgradeToAndCall(
+      this.implUpgradeOk.address,
+      this.implUpgradeOk.contract.methods.increment().encodeABI(),
+    );
+    expect(receipt.logs.filter(({ event }) => event === 'Upgraded').length).to.be.equal(1);
+    expectEvent(receipt, 'Upgraded', { implementation: this.implUpgradeOk.address });
+
+    expect(await this.instance.current()).to.be.bignumber.equal('1');
+  });
+
+  it('upgrade to and unsafe upgradeable implementation', async function () {
+    const { receipt } = await this.instance.upgradeTo(this.implUpgradeUnsafe.address);
+    expectEvent(receipt, 'Upgraded', { implementation: this.implUpgradeUnsafe.address });
+  });
+
+  it('reject upgrade to broken upgradeable implementation', async function () {
+    await expectRevert(
+      this.instance.upgradeTo(this.implUpgradeBroken.address),
+      'ERC1967Upgrade: upgrade breaks further upgrades',
+    );
+  });
+
+  // delegate to a non existing upgradeTo function causes a low level revert
+  it('reject upgrade to non uups implementation', async function () {
+    await expectRevert(
+      this.instance.upgradeTo(this.implUpgradeNonUUPS.address),
+      'Address: low-level delegate call failed',
+    );
+  });
+
+  it('reject proxy address as implementation', async function () {
+    const { address } = await ERC1967Proxy.new(this.implInitial.address, '0x');
+    const otherInstance = await UUPSUpgradeableMock.at(address);
+
+    // infinite loop reverts when a nested call is out-of-gas
+    await expectRevert(
+      this.instance.upgradeTo(otherInstance.address),
+      'Address: low-level delegate call failed',
+    );
+  });
+});