diff --git a/sumAll/sumAll.js b/sumAll/sumAll.js
index 863a79d..1429afa 100644
--- a/sumAll/sumAll.js
+++ b/sumAll/sumAll.js
@@ -1,5 +1,16 @@
-var sumAll = function() {
+const sumAll = function(min, max) {
+  if (min < 0 || max < 0) return "ERROR";
+  if (typeof min !== "number" || typeof max !== "number") return "ERROR";
+  if (min > max) {
+    const temp = min;
+    min = max;
+    max = temp;
+  }
+  let sum = 0;
+  for (let i = min; i < max + 1; i++) {
+    sum += i;
+  }
+  return sum;
+};
 
-}
-
-module.exports = sumAll
+module.exports = sumAll;
diff --git a/sumAll/sumAll.spec.js b/sumAll/sumAll.spec.js
index 7f48e7a..1b3fa3c 100644
--- a/sumAll/sumAll.spec.js
+++ b/sumAll/sumAll.spec.js
@@ -1,22 +1,22 @@
-var sumAll = require('./sumAll')
+const sumAll = require("./sumAll");
 
-describe('sumAll', function() {
-  it('sums numbers within the range', function() {
+describe("sumAll", () => {
+  it("sums numbers within the range", () => {
     expect(sumAll(1, 4)).toEqual(10);
   });
-  xit('works with large numbers', function() {
+  it("works with large numbers", () => {
     expect(sumAll(1, 4000)).toEqual(8002000);
   });
-  xit('works with larger number first', function() {
+  it("works with larger number first", () => {
     expect(sumAll(123, 1)).toEqual(7626);
   });
-  xit('returns ERROR with negative numbers', function() {
-    expect(sumAll(-10, 4)).toEqual('ERROR');
+  it("returns ERROR with negative numbers", () => {
+    expect(sumAll(-10, 4)).toEqual("ERROR");
   });
-  xit('returns ERROR with non-number parameters', function() {
-    expect(sumAll(10, "90")).toEqual('ERROR');
+  it("returns ERROR with non-number parameters", () => {
+    expect(sumAll(10, "90")).toEqual("ERROR");
   });
-  xit('returns ERROR with non-number parameters', function() {
-    expect(sumAll(10, [90, 1])).toEqual('ERROR');
+  it("returns ERROR with non-number parameters", () => {
+    expect(sumAll(10, [90, 1])).toEqual("ERROR");
   });
 });