diff --git a/src/restoreNames.test.js b/src/restoreNames.test.js
index 6310350..5e5a0dc 100644
--- a/src/restoreNames.test.js
+++ b/src/restoreNames.test.js
@@ -1,11 +1,46 @@
-'use strict';
+"use strict";
 
-describe('restoreNames', () => {
-  // const { restoreNames } = require('./restoreNames');
+describe("restoreNames", () => {
+  const { restoreNames } = require("./restoreNames");
 
-  it('should ', () => {
+  it("should not return value", () => {
+    const users = [
+      {
+        firstName: undefined,
+        lastName: "Holy",
+        fullName: "Jack Holy",
+      },
+      {
+        lastName: "Adams",
+        fullName: "Mike Adams",
+      },
+    ];
+    const result = restoreNames(users);
 
+    expect(result).toBe(undefined);
   });
 
-  // write tests here
+  it("should be a function", () => {
+    expect(restoreNames).toBeInstanceOf(Function);
+  });
+
+  it("firstName should be equal first part of fullName", () => {
+    const users = [
+      {
+        firstName: undefined,
+        lastName: "Holy",
+        fullName: "Jack Holy",
+      },
+      {
+        lastName: "Adams",
+        fullName: "Mike Adams",
+      },
+    ];
+
+    restoreNames(users);
+
+    users.forEach((item, index) => {
+      expect(item.firstName).toBe(item.fullName.split(" ")[0]);
+    });
+  });
 });