Added Jest

sumAll/sumAll.js

@@ -1,5 +1,15 @@
-const sumAll = function() {
-
+const sumAll = function (numStart, numEnd) {
+  // final sum variable
+  let sum = 0;
+  if (numStart < 0 || numEnd < 0 || typeof numStart != "number" || typeof numEnd != "number") {
+    return "ERROR";
+  } else if (numStart > numEnd) {
+    [numStart, numEnd] = [numEnd, numStart];
+  }
+  for (let i = numStart; i <= numEnd; i++) {
+    sum += i;
+  }
+  return sum;
 };
 
 module.exports = sumAll;

sumAll/sumAll.spec.js

@@ -1,22 +1,22 @@
-const sumAll = require('./sumAll')
+const sumAll = require("./sumAll");
 
-describe('sumAll', () => {
-  test('sums numbers within the range', () => {
+describe("sumAll", () => {
+  test("sums numbers within the range", () => {
     expect(sumAll(1, 4)).toEqual(10);
   });
-  test.skip('works with large numbers', () => {
+  test("works with large numbers", () => {
     expect(sumAll(1, 4000)).toEqual(8002000);
   });
-  test.skip('works with larger number first', () => {
+  test("works with larger number first", () => {
     expect(sumAll(123, 1)).toEqual(7626);
   });
-  test.skip('returns ERROR with negative numbers', () => {
-    expect(sumAll(-10, 4)).toEqual('ERROR');
+  test("returns ERROR with negative numbers", () => {
+    expect(sumAll(-10, 4)).toEqual("ERROR");
   });
-  test.skip('returns ERROR with non-number parameters', () => {
-    expect(sumAll(10, "90")).toEqual('ERROR');
+  test("returns ERROR with non-number parameters", () => {
+    expect(sumAll(10, "90")).toEqual("ERROR");
   });
-  test.skip('returns ERROR with non-number parameters', () => {
-    expect(sumAll(10, [90, 1])).toEqual('ERROR');
+  test("returns ERROR with non-number parameters", () => {
+    expect(sumAll(10, [90, 1])).toEqual("ERROR");
   });
 });