implemented solutions to hello world and leap year

helloWorld/helloWorld.js

@@ -1,5 +1,5 @@
-const helloWorld = function() {
-  return ''
+const helloWorld = () => {
+  return 'Hello, World!'
 };
 
 module.exports = helloWorld;

leapYears/leapYears.js

@@ -1,5 +1,19 @@
-const leapYears = function() {
+const leapYears = (year) => {
 
+    const modulo = year % 4;
+        if (modulo === 0 ){
+            if(year % 100 === 0){
+                if (year % 400 === 0){
+                    return true;
+                } else {
+                    return false;
+                }
+            } 
+            return true;
+   
+        } 
+    return false;    
 };
 
 module.exports = leapYears;
+

leapYears/leapYears.spec.js

@@ -4,19 +4,20 @@ describe('leapYears', () => {
   test('works with non century years', () => {
     expect(leapYears(1996)).toBe(true);
   });
-  test.skip('works with non century years', () => {
+
+  test('works with non century years', () => {
     expect(leapYears(1997)).toBe(false);
   });
-  test.skip('works with ridiculously futuristic non century years', () => {
+  test('works with ridiculously futuristic non century years', () => {
     expect(leapYears(34992)).toBe(true);
   });
-  test.skip('works with century years', () => {
+  test('works with century years', () => {
     expect(leapYears(1900)).toBe(false);
   });
-  test.skip('works with century years', () => {
+  test('works with century years', () => {
     expect(leapYears(1600)).toBe(true);
   });
-  test.skip('works with century years', () => {
+  test('works with century years', () => {
     expect(leapYears(700)).toBe(false);
   });
 });