Reorganize the repo structure (#2503)

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

test/utils/structs/EnumerableSet.test.js

@@ -0,0 +1,46 @@
+const { BN } = require('@openzeppelin/test-helpers');
+
+const EnumerableBytes32SetMock = artifacts.require('EnumerableBytes32SetMock');
+const EnumerableAddressSetMock = artifacts.require('EnumerableAddressSetMock');
+const EnumerableUintSetMock = artifacts.require('EnumerableUintSetMock');
+
+const { shouldBehaveLikeSet } = require('./EnumerableSet.behavior');
+
+contract('EnumerableSet', function (accounts) {
+  // Bytes32Set
+  describe('EnumerableBytes32Set', function () {
+    const bytesA = '0xdeadbeef'.padEnd(66, '0');
+    const bytesB = '0x0123456789'.padEnd(66, '0');
+    const bytesC = '0x42424242'.padEnd(66, '0');
+
+    beforeEach(async function () {
+      this.set = await EnumerableBytes32SetMock.new();
+    });
+
+    shouldBehaveLikeSet(bytesA, bytesB, bytesC);
+  });
+
+  // AddressSet
+  describe('EnumerableAddressSet', function () {
+    const [accountA, accountB, accountC] = accounts;
+
+    beforeEach(async function () {
+      this.set = await EnumerableAddressSetMock.new();
+    });
+
+    shouldBehaveLikeSet(accountA, accountB, accountC);
+  });
+
+  // UintSet
+  describe('EnumerableUintSet', function () {
+    const uintA = new BN('1234');
+    const uintB = new BN('5678');
+    const uintC = new BN('9101112');
+
+    beforeEach(async function () {
+      this.set = await EnumerableUintSetMock.new();
+    });
+
+    shouldBehaveLikeSet(uintA, uintB, uintC);
+  });
+});