Reorganize the repo structure (#2503)

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

test/utils/math/Math.test.js

@@ -0,0 +1,58 @@
+const { BN } = require('@openzeppelin/test-helpers');
+
+const { expect } = require('chai');
+
+const MathMock = artifacts.require('MathMock');
+
+contract('Math', function (accounts) {
+  const min = new BN('1234');
+  const max = new BN('5678');
+
+  beforeEach(async function () {
+    this.math = await MathMock.new();
+  });
+
+  describe('max', function () {
+    it('is correctly detected in first argument position', async function () {
+      expect(await this.math.max(max, min)).to.be.bignumber.equal(max);
+    });
+
+    it('is correctly detected in second argument position', async function () {
+      expect(await this.math.max(min, max)).to.be.bignumber.equal(max);
+    });
+  });
+
+  describe('min', function () {
+    it('is correctly detected in first argument position', async function () {
+      expect(await this.math.min(min, max)).to.be.bignumber.equal(min);
+    });
+
+    it('is correctly detected in second argument position', async function () {
+      expect(await this.math.min(max, min)).to.be.bignumber.equal(min);
+    });
+  });
+
+  describe('average', function () {
+    function bnAverage (a, b) {
+      return a.add(b).divn(2);
+    }
+
+    it('is correctly calculated with two odd numbers', async function () {
+      const a = new BN('57417');
+      const b = new BN('95431');
+      expect(await this.math.average(a, b)).to.be.bignumber.equal(bnAverage(a, b));
+    });
+
+    it('is correctly calculated with two even numbers', async function () {
+      const a = new BN('42304');
+      const b = new BN('84346');
+      expect(await this.math.average(a, b)).to.be.bignumber.equal(bnAverage(a, b));
+    });
+
+    it('is correctly calculated with one even and one odd number', async function () {
+      const a = new BN('57417');
+      const b = new BN('84346');
+      expect(await this.math.average(a, b)).to.be.bignumber.equal(bnAverage(a, b));
+    });
+  });
+});