algorithm: Hexagonal number (#1265)

Maths/test/HexagonalNumber.test.js

@@ -0,0 +1,19 @@
+import { hexagonalNumber } from '../HexagonalNumber'
+
+const expectedValuesArray = [1, 6, 15, 28, 45, 66, 91, 120, 153, 190, 231, 276, 325, 378, 435, 496, 561, 630, 703, 780, 861, 946]
+
+describe('Testing hexagonalNumber', () => {
+  for (let i = 1; i <= 22; i++) {
+    it('Testing for number = ' + i + ', should return ' + expectedValuesArray[i], () => {
+      expect(hexagonalNumber(i)).toBe(expectedValuesArray[i - 1])
+    })
+  }
+
+  it('should throw error when supplied negative numbers', () => {
+    expect(() => { hexagonalNumber(-1) }).toThrow(Error)
+  })
+
+  it('should throw error when supplied zero', () => {
+    expect(() => { hexagonalNumber(0) }).toThrow(Error)
+  })
+})