.only() no longer works with nested describe()s in Mocha 3.0.0

[adamjmurray]

I was excited to see improvements to .only() in the Mocha 3.0.0 changelog. It's mostly working well, but I found a regression. Consider the following test file with nested describe()s:

var assert = require('assert');

describe('Array', function() {

  describe('.push()', function() {

    it('appends a value to the end of the array', function() {
      var array = [1];
      array.push(2);
      assert.deepEqual(array, [1, 2]);
    });

    it('can append more than one value to the end of the array', function() {
      var array = [1];
      array.push(2, 3);
      assert.deepEqual(array, [1, 2, 3]);
    });
  });

  describe('.reverse()', function() {

    it('reverses a non-empty array', function() {
      assert.deepEqual([1, 2, 3].reverse(), [3, 2, 1]);
    });

    it('does nothing to an empty array', function() {
      assert.deepEqual([].reverse(), []);
    });
  });
});

In previous versions of mocha, you could add a .only() to one of the inner describe()s and it would do what you expect. For example, if I changed that file to look like:

  describe.only('.push()', function() {

It should run 2 tests. That's the way previous versions of Mocha behaved. It's a very useful behavior that my team uses every day.

In Mocha 3.0.0 it runs 0 tests.

A few other notes:

• .only() on the top-most describe() in a file works fine
• changing describe() to context() doesn't affect the behavior (same issue with context())

[boneskull]

I was worried about this, but unfortunately didn't get enough review or help with the code in question before it went out.

[boneskull]

This is published as v3.0.1; thanks again @not-an-aardvark