diff --git a/Unit Tests/package.json b/Unit Tests/package.json
new file mode 100644
index 0000000..9f8606d
--- /dev/null
+++ b/Unit Tests/package.json	
@@ -0,0 +1,20 @@
+{
+  "name": "tests",
+  "version": "1.0.0",
+  "description": "",
+  "main": "server.js",
+  "dependencies": {
+    "cors": "^2.8.5",
+    "express": "^4.17.1"
+  },
+  "devDependencies": {
+    "jest": "^26.6.3"
+  },
+  "scripts": {
+    "test": "npx jest",
+    "start": "node server.js"
+  },
+  "keywords": [],
+  "author": "",
+  "license": "ISC"
+}
diff --git a/Unit Tests/validatepreviousURL.js b/Unit Tests/validatepreviousURL.js
new file mode 100644
index 0000000..3ba4054
--- /dev/null
+++ b/Unit Tests/validatepreviousURL.js	
@@ -0,0 +1,8 @@
+var validatePreviousURL = function (url) {
+//document.referrer
+const urlBefore = url.indexOf('codepen') > -1;
+
+return urlBefore
+}
+
+validatePreviousURL(document.referrer);
\ No newline at end of file
diff --git a/Unit Tests/validatepreviousURL.test.js b/Unit Tests/validatepreviousURL.test.js
new file mode 100644
index 0000000..b80cd56
--- /dev/null
+++ b/Unit Tests/validatepreviousURL.test.js	
@@ -0,0 +1,11 @@
+var validatepreviousURL = function (url) {
+    //document.referrer
+    const urlBefore = url.indexOf('codepen') > -1;
+    
+    return urlBefore
+}
+
+//Tests
+test('Retuns False cause previous URL does not match with the regex', () => {
+expect(validatepreviousURL("google.com")).toBe(false)
+})
\ No newline at end of file