Revert unwanted breaking change in the Clones library (#3456)

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

test/helpers/create2.js

@@ -0,0 +1,12 @@
+function computeCreate2Address (saltHex, bytecode, deployer) {
+  return web3.utils.toChecksumAddress(`0x${web3.utils.sha3(`0x${[
+    'ff',
+    deployer,
+    saltHex,
+    web3.utils.soliditySha3(bytecode),
+  ].map(x => x.replace(/0x/, '')).join('')}`).slice(-40)}`);
+}
+
+module.exports = {
+  computeCreate2Address,
+};

test/proxy/Clones.test.js

@@ -1,4 +1,6 @@
 const { expectEvent, expectRevert } = require('@openzeppelin/test-helpers');
+const { computeCreate2Address } = require('../helpers/create2');
+const { expect } = require('chai');
 
 const shouldBehaveLikeClone = require('./Clones.behaviour');
 
@@ -44,6 +46,19 @@ contract('Clones', function (accounts) {
       const salt = web3.utils.randomHex(32);
       const factory = await ClonesMock.new();
       const predicted = await factory.predictDeterministicAddress(implementation, salt);
+
+      const creationCode = [
+        '0x3d602d80600a3d3981f3363d3d373d3d3d363d73',
+        implementation.replace(/0x/, '').toLowerCase(),
+        '5af43d82803e903d91602b57fd5bf3',
+      ].join('');
+
+      expect(computeCreate2Address(
+        salt,
+        creationCode,
+        factory.address,
+      )).to.be.equal(predicted);
+
       expectEvent(
         await factory.cloneDeterministic(implementation, salt, '0x'),
         'NewInstance',

test/utils/Create2.test.js

@@ -1,5 +1,5 @@
 const { balance, BN, ether, expectRevert, send } = require('@openzeppelin/test-helpers');
-
+const { computeCreate2Address } = require('../helpers/create2');
 const { expect } = require('chai');
 
 const Create2Impl = artifacts.require('Create2Impl');
@@ -90,12 +90,3 @@ contract('Create2', function (accounts) {
     });
   });
 });
-
-function computeCreate2Address (saltHex, bytecode, deployer) {
-  return web3.utils.toChecksumAddress(`0x${web3.utils.sha3(`0x${[
-    'ff',
-    deployer,
-    saltHex,
-    web3.utils.soliditySha3(bytecode),
-  ].map(x => x.replace(/0x/, '')).join('')}`).slice(-40)}`);
-}