Proof of concept for https://github.com/mochajs/mocha/issues/1481

.gitignore

node_modules/

package.json

{
  "name": "gist-mocha-only",
  "version": "1.0.0",
  "description": "Proof of concept for https://github.com/mochajs/mocha/issues/1481",
  "main": "index.js",
  "scripts": {
    "test": "mocha test-one.js test-two.js"
  },
  "repository": {
    "type": "git",
    "url": "git@gist.github.com:9b769b716dd7bad383ac.git"
  },
  "author": "Todd Wolfson <todd@twolfson.com> (http://twolfson.com/)",
  "license": "UNLICENSE",
  "devDependencies": {
    "mocha": "~2.1.0"
  }
}

test-one.js

// Load in dependencies
var assert = require('assert');

// Start our tests
describe.only('one with a .only', function () {
  it('is run separately from other tests', function () {
    assert.strictEqual(1, 1);
  });
});

test-two.js

// Load in dependencies
var assert = require('assert');

// Start our tests
describe('two without a .only', function () {
  it('is not run', function () {
    assert.strictEqual(1, 2);
  });
});