Updated the code and did the required changes

Bit-Manipulation/IsPowerOfTwo.js

@@ -4,14 +4,25 @@
     This script will check whether the given
     number is a power of two or not.
 
+    A number will be a power of two if only one bit is set and rest are unset.
+    This is true for all the cases except 01 because (2^0 = 1) which is not a power of 2.
+    For eg: 10 (2^1 = 2), 100 (2^2 = 4), 10000 (2^4 = 16)
+
+    Reference Link: https://www.hackerearth.com/practice/notes/round-a-number-to-the-next-power-of-2/
+
+    If we will subtract 1 from a number that is a power of 2 we will get it's 1's complement.
+    And we know that 1's complement is just opp. of that number.
+    So, (n & (n-1)) will be 0.
+
+    For eg:    (1000 & (1000-1)) 
+                1 0 0 0     // Original Number (8)
+                0 1 1 1     // After Subtracting 1 (8-1 = 7)
+                _______
+                0 0 0 0     // will become 0
+
 */
 
 export const IsPowerOfTwo = (n) => {
-    if ((n&(n-1))==0 && n!=0)
-        return true;
-    else
-        return false;
+  if (n != 0 && (n & (n - 1)) == 0) return true
+  else return false
 }
-  
-// console.log(IsPowerOfTwo(0));
-  

Bit-Manipulation/test/IsPowerOfTwo.test.js

@@ -1,7 +1,12 @@
 import {IsPowerOfTwo} from '../IsPowerOfTwo'
 
 test('Check if 0 is a power of 2 or not:', () => {
-  const res = IsPowerOfTwo(1, 0)
+  const res = IsPowerOfTwo(0)
+  expect(res).toBe(false)
+})
+
+test('Check if 0 is a power of 2 or not:', () => {
+  const res = IsPowerOfTwo(1)
   expect(res).toBe(false)
 })