feat(getTriangleType): get type of a Triangle (#252)

Author: bolah2009

src/getTriangleType.js

@@ -0,0 +1,19 @@
+export default getTriangleType
+
+/**
+ * Original Source: https://stackoverflow.com/questions/12491976
+ *
+ * This function will return the type of a triangle, given its sides (a, b, c) length. It's a copy.
+ *
+ * @param {String} a - The sides to determine which triangle it belongs to
+ * @param {String} b - The sides to determine which triangle it belongs to
+ * @param {String} c - The sides to determine which triangle it belongs to
+ * @return {String} (Equilateral, Isosceles and Scalene) - The type of triangle
+ */
+function getTriangleType(a, b, c) {
+  return (
+    (a === b && b === c && 'Equilateral') ||
+    ((a === b || a === c || b === c) && 'Isosceles') ||
+    'Scalene'
+  )
+}

src/index.js

@@ -93,6 +93,7 @@ import clone from './clone'
 import arrMultiply from './array-multiplier'
 import second from './second'
 import armstrong from './armstrong'
+import getTriangleType from './getTriangleType'
 
 export {
   reverseArrayInPlace,
@@ -190,4 +191,6 @@ export {
   arrMultiply,
   second,
   armstrong,
+  getTriangleType,
+  
 }

test/getTriangleType.test.js

@@ -0,0 +1,29 @@
+import test from 'ava'
+import {getTriangleType} from '../src'
+
+test('gets the type of a triangle when Equilateral', t => {
+  const a = 10
+  const b = 10
+  const c = 10
+  const expected = 'Equilateral'
+  const actual = getTriangleType(a, b, c)
+  t.deepEqual(actual, expected)
+})
+
+test('gets the type of a triangle when Isosceles', t => {
+  const a = 10
+  const b = 20
+  const c = 20
+  const expected = 'Isosceles'
+  const actual = getTriangleType(a, b, c)
+  t.deepEqual(actual, expected)
+})
+
+test('gets the type of a triangle when Scalene', t => {
+  const a = 10
+  const b = 20
+  const c = 30
+  const expected = 'Scalene'
+  const actual = getTriangleType(a, b, c)
+  t.deepEqual(actual, expected)
+})