soft zeros to left in an integer array

sort-zero-to-left.js

//Given an integer array
//move all elements that are equal to 0 to the left while maintaining the order of other elements in the array.



//[1,0,2,0,3] => [0,0,1,2,3];

/*
[1,0,2,0,3]
[0,1,2,0,3]
[0,0,1,2,3]

[1,2,3,4,5,6,7,8,0]
[1,2,3,4,5,6,7,0,8]
[1,2,3,4,5,6,0,7,8]
[1,2,3,4,5,0,6,7,8]
[1,2,3,4,0,5,6,7,8]
[1,2,3,0,4,5,6,7,8]
[1,2,0,3,4,5,6,7,8]
[1,0,2,3,4,5,6,7,8]
[0,1,2,3,4,5,6,7,8]

*/
var Mocha = require('mocha')
var assert = require('assert')
var mocha = new Mocha()

const sortZeroToLeft = (array) => {
  for (let i = 0; i < array.length; ++i) {
    if (array[i] === 0) {
      array.splice(i,1);
      array.unshift(0);
    }
   }
   return array;
}


const sortZeroToLeft2 = (array) => {
  return array.sort((a,b) => {
    if(a === 0 && b === 0)
    {
      return 0; 
    }
    if(a === 0)
    {
      return -1 
    }
    return 1;
  });
}



// Bit of a hack, sorry!
mocha.suite.emit('pre-require', this, 'solution', mocha)

describe('sortZeroToLeft', () => {
  it('should work with standard test cases', function() {
    assert.deepEqual(sortZeroToLeft([1, 0]), [0, 1]);
    assert.deepEqual(sortZeroToLeft([1,0,2,0,3]), [0,0,1,2,3]);
    assert.deepEqual(sortZeroToLeft([1,2,3,4,5,6,7,8,0]), [0,1,2,3,4,5,6,7,8]);
  });
  it('should handle empty array',() => {
    assert.deepEqual(sortZeroToLeft([]), []);
  });  
})

describe('sortZeroToLeft 2', () => {
  it('should work with standard test cases', function() {
    assert.deepEqual(sortZeroToLeft2([1, 0]), [0, 1]);
    assert.deepEqual(sortZeroToLeft2([1,0,2,0,3]), [0,0,1,2,3]);
    assert.deepStrictEqual(sortZeroToLeft2([1,2,3,4,5,6,7,8,0]), [0,1,2,3,4,5,6,7,8]);
    assert.deepStrictEqual(sortZeroToLeft2([1,10,-1,11,5,0,-7,0,25,-35]), [0,0,1,10,-1,11,5,-7,25,-35]);
  });
  it('should handle empty array',() => {
    assert.deepEqual(sortZeroToLeft2([]), []);
  });  
})

mocha.run()