Use co-mocha for tests

[techniq]

Would you be opposed if I converted all the tests to use co-mocha? I was looking to submitting some pull requests and thought the specs were a little difficult to follow with all the Promise flow and thought it would help their readability greatly.

For example, here is the current create.spec.js using mocha and Promise then/catch

describe('DSSqlAdapter#create', function () {
  it('should create a user in a sql db', function () {
    var id;
    return adapter.create(User, {name: 'John'}).then(function (user) {
      id = user.id;
      assert.equal(user.name, 'John');
      assert.isDefined(user.id);
      return adapter.find(User, user.id);
    })
      .then(function (user) {
        assert.equal(user.name, 'John');
        assert.isDefined(user.id);
        assert.equalObjects(user, {id: id, name: 'John', age: null, profileId: null});
        return adapter.destroy(User, user.id);
      })
      .then(function (user) {
        assert.isFalse(!!user);
        return adapter.find(User, id);
      })
      .then(function () {
        throw new Error('Should not have reached here!');
      })
      .catch(function (err) {
        assert.equal(err.message, 'Not Found!');
      });
  });
});

and the same test using co-mocha with yielding promises

describe('DSSqlAdapter#create', function () {
  it('should create a user in a sql db', function* () {
    var createUser = yield adapter.create(User, {name: 'John'});
    var id = createUser.id;
    assert.equal(createUser.name, 'John');
    assert.isDefined(createUser.id);

    var findUser = yield adapter.find(User, createUser.id);
    assert.equal(findUser.name, 'John');
    assert.isDefined(findUser.id);
    assert.equalObjects(findUser, {id: id, name: 'John', age: null, profileId: null});

    var destoryUser = yield adapter.destroy(User, findUser.id);
    assert.isFalse(!!destoryUser);

    try {
      var findUser2 = yield adapter.find(User, id);
      throw new Error('Should not have reached here!');
    } catch(err) {
      assert.equal(err.message, 'Not Found!');
    }
  });
});

I'll finish and submit the change as a PR, but didn't want to make this kind of change without your consent :).

As for the PRs I was thinking about tackling

• Implement Filter across relation (joins) #18 (but if you can knock it out quicker, that would be awesome)
• Consolidate the relation handling inside find() and findAll() (basically extract it into a processRelations()
• I'd like to find a way use MySQL's spatial queries but still get the benefits of js-data-sql's relations (primarily with and putting the nested objects together).
  • One idea I was thinking about having findAll detect if the second parameter (current params) is an instance of a knex query builder and use that query to process instead of the one returned from filterQuery(). For example: sqlAdapter.findAll(Race, query, { with: 'address' })
  • Another idea was to just export the new processRelations() and use it directly. For example: sqlAdapter.processRelations(Race, yield sqlAdapter.query(...), { with: 'address' }) although I haven't thought on this API very much as to what would work best.

[jmdobry]

This all sounds fine to me, go ahead and PR.