NYC output is empty

I have been trying for hours to find the problem here, but I can’t, I tried many things, this is my test file (unit-test.js) inside projectRoot/test

var should = require('should');


var arr = [1, 2, 3];
function ap(ar) {
  a = ar;
  var L = a.length;
  if (L > 1) {
    a[L] = 4;
  }
  console.log(a);
  return a;
}

describe('#indexOf()', function () {
  it('should return -1 when the value is not present', function () {
    if (arr.length > 1) {
      should.equal(ap(arr)[3], 4);
      //should.equal(arr[2],3);
    }
  });
});

And this is my package.json:

{
  "name": "jsonave-test",
  "version": "1.0.0",
  "description": "",
  "main": "index.js",
  "scripts": {
    "lint": "eslint .",
   "test": " mocha test/unit-test.js --check-leaks --recursive --exit",
    "cover": "nyc npm test"
  },
  "author": "",
  "license": "ISC",
  "dependencies": {
    "http": "0.0.0",
    "jsonapter": "^2.0.3",
    "jsonave": "0.0.3",
    "moment": "^2.21.0",
    "nock": "^9.2.3",
    "should": "^13.2.1"
  },
  "devDependencies": {
    "eslint": "^4.19.1",
    "nyc": "^11.7.1"
  }
}

when i run , the output shows coverage all 0% and no file name is mentioned, as shown below

$ npm run cover

> jsonave-test@1.0.0 cover C:\Users\h\WebstormProjects\jsonave-test
> nyc mocha



  #indexOf()
[ 1, 2, 3, 4 ]
    √ should return -1 when the value is not present


  1 passing (0ms)

----------|----------|----------|----------|----------|-------------------|
File      |  % Stmts | % Branch |  % Funcs |  % Lines | Uncovered Line #s |
----------|----------|----------|----------|----------|-------------------|
All files |        0 |        0 |        0 |        0 |                   |
----------|----------|----------|----------|----------|-------------------|