test: add test for 0001_two_sum.js

Author: Saimon398

js_solutions/0001_two_sum.js

@@ -5,7 +5,7 @@
  * @param {Number} target
  * @returns {Object []}
  */
-const twoSum = (nums, target) => {
+export default (nums, target) => {
   // key: Number that adds up to target
   // value: Index the number is at
   const twoSum = {};

package-lock.json

@@ -18,6 +18,7 @@
   },
   "homepage": "https://github.com/Saimon398/Problem-Solution#readme",
   "devDependencies": {
+    "@jest/globals": "^29.2.2",
     "eslint": "^8.26.0",
     "eslint-config-airbnb-base": "^15.0.0",
     "eslint-plugin-import": "^2.26.0",

package.json

@@ -0,0 +1,19 @@
+import { describe, test, expect } from '@jest/globals';
+import twoSum from '../js_solutions/0001_two_sum.js';
+
+describe('Testing twoSum function', () => {
+  test('Testing with different values', () => {
+  // Should return indices of the two numbers such that they add up to target.
+    expect(twoSum([2, 7, 11, 15], 9)).toEqual(expect.arrayContaining([0, 1]));
+    expect(twoSum([3, 2, 4], 6)).toEqual(expect.arrayContaining([1, 2]));
+  });
+  test('Testing with the same values', () => {
+    expect(twoSum([3, 3], 6)).toEqual(expect.arrayContaining([0, 1]));
+    expect(twoSum([4, 4], 8)).toEqual(expect.arrayContaining([0, 1]));
+  });
+  // Should return -1, b/c there is no solution or solution is not the only one
+  test('Testing with the absence of solution', () => {
+    expect(twoSum([1, 2, 5], 4)).toEqual(-1);
+    expect(twoSum([4, 4, 4, 4], 16)).toEqual(-1);
+  });
+});