I have two javascript files which contain mocha test cases.

//----------abc.js -------------



describe(abc file, function(){

  it(test 1 , function(){

    assert.equal(20 , 20); 

  });

}); 



//---------xyz.js--------------

describe(xyz file, function(){

      it(test 1 , function(){

        assert.equal(10 , 10); 

      });

    });

I have put them in a folder called test and when I execute the mocha command the first file(abc.js) is always executed before xyz.js.
I thought this might be due to alphabetical ordering and renamed the files as

abc.js => xyz.js

xyz.js => abc.js

but still, the content of the xyz.js (previously abc.js) is executed first. How can I change the execution order of these test files?