Add unit tests for "find-2-nums-adding-to-n". Fix findTwoNumsAddingToN2 so it only returns one pair

Author: mattstates

package-lock.json

@@ -0,0 +1,34 @@
+const { findTwoNumsAddingToN, findTwoNumsAddingToN2 } = require('.');
+
+describe('Find two numbers adding to N', () => {
+  [findTwoNumsAddingToN, findTwoNumsAddingToN2].forEach((func) => {
+    describe(func.name, () => {
+      it('Should return an array with length two', () => {
+        expect(findTwoNumsAddingToN2([1, 2], 3).length).toBe(2);
+      });
+
+      it('Should return false when there is no solution', () => {
+        expect(findTwoNumsAddingToN2([1, 2], 5)).toBe(false);
+      });
+
+      it('Should return false input array length is less than 2', () => {
+        expect(findTwoNumsAddingToN2([5], 5)).toBe(false);
+      });
+
+      it('Should return negative values', () => {
+        expect(findTwoNumsAddingToN2([-2, 1, 2, 6, 7], 5)).toEqual(expect.arrayContaining([-2, 7]));
+      });
+
+      it('Should return two numbers that sum to N', () => {
+        expect(findTwoNumsAddingToN([1, 2, 3, 5], 5)).toEqual(expect.arrayContaining([2, 3]));
+      });
+    });
+  });
+
+  describe('function differences findTwoNumsAddingToN and findTwoNumsAddingToN2', () => {
+    it('Should return different arrays', () => {
+      expect(findTwoNumsAddingToN([1, 2, 3, 4], 5))
+        .toEqual(expect.not.arrayContaining(findTwoNumsAddingToN2([1, 2, 3, 4], 5)));
+    });
+  });
+});

src/_Problems_/find-2-nums-adding-to-n/find-2-nums-adding-to-n.test.js

@@ -18,15 +18,19 @@ function findTwoNumsAddingToN(arr, number) {
 
 // the Brute force approach
 function findTwoNumsAddingToN2(arr, number) {
-  const pair = [];
+
   for (let i = 0; i < arr.length; i += 1) {
     for (let j = i + 1; j < arr.length; j += 1) {
       if (arr[i] + arr[j] === number) {
-        pair.push(arr[i], arr[j]);
-        break;
+        return [arr[i], arr[j]];
       }
     }
   }
 
-  return pair.length ? pair : false;
+  return false;
 }
+
+module.exports = {
+  findTwoNumsAddingToN,
+  findTwoNumsAddingToN2,
+};