diff --git a/src/isIsogram.test.js b/src/isIsogram.test.js
index dfb16184..2586a4f1 100644
--- a/src/isIsogram.test.js
+++ b/src/isIsogram.test.js
@@ -1,9 +1,27 @@
-'use strict';
+"use strict";
 
-describe('isIsogram', () => {
-  const { isIsogram } = require('./isIsogram');
+describe("isIsogram", () => {
+  const { isIsogram } = require("./isIsogram");
 
   it(`should be declared`, () => {
     expect(isIsogram).toBeInstanceOf(Function);
   });
+
+  const isIsogramMap = {
+    playgrounds: true,
+    look: false,
+    Adam: false,
+    "": true,
+    Oops: false,
+  };
+
+  for (const key in isIsogramMap) {
+    it(
+      `should ${isIsogramMap[key]} if ${key === "" ? "space" : key} ` +
+        "passed",
+      () => {
+        expect(isIsogram(key)).toBe(isIsogramMap[key]);
+      },
+    );
+  }
 });