5.4 my solution

Author: amejiarosario

src/05-bits/04-next-number.js

@@ -7,7 +7,29 @@
  * @param number
  */
 function nextNumber(number) {
+  // min - swap zeros and 1 until all ones are in the right side
+  let min = swapper(number);
 
+  // max - swap 0's and 1's until all ones are on the left side
+  let max = swapper(number, false);
+
+  return [min, max];
+}
+
+function swapper(number, toRight = true) {
+  const result = [];
+  const action = toRight ? {one: 'push', zero: 'unshift'} : {one: 'unshift', zero: 'push'};
+
+  while(number > 0) {
+    if(number & 1) {
+      result[action.one](1);
+    } else {
+      result[action.zero](0);
+    }
+    number >>= 1;
+  }
+
+  return parseInt(result.join(''), 2);
 }
 
 module.exports = nextNumber;

src/05-bits/04-next-number.spec.js

@@ -1,16 +1,16 @@
 const expect = require('chai').expect;
-const nextNumber = require('./03-flip-bit-to-win');
+const nextNumber = require('./04-next-number');
 
 describe('Bit Manipulation: nextNumber', function() {
   it('one zero', function() {
-    expect(nextNumber(0b101)).to.equal([11, 110]);
+    expect(nextNumber(0b101)).to.eql([0b11, 0b110]);
   });
 
   it('all ones', function() {
-    expect(nextNumber(0b111)).to.equal([111, 111]);
+    expect(nextNumber(0b111)).to.eql([0b111, 0b111]);
   });
 
   it('largest number already', function() {
-    expect(nextNumber(0b100)).to.equal([1, 100]);
+    expect(nextNumber(0b100)).to.eql([0b1, 0b100]);
   });
 });