fix(modal): ensure correct index is set for new modals

[josetaira]

Fix how the index for the modal and the backdrop are set, depending on
what index value the previous top modal has.

Closes #5670

[wesleycho]

Add a space after if

[wesleycho]

Can you add a unit test for this?

[josetaira]

For the tests, no idea how grunt works, but I guess I can learn it. Do you have any templates or guidelines on how tests should be made?

[icfantv]

@josetaira, you don't need to learn grunt, you need to look at the model.spec.js file and add your tests to that file and they'll run as part of the build. there should be enough examples in there (and our other test files) to figure it out.

if you want to run a specific test or test suite, simply prefix the it or describe with an f (i.e. fit or fdescribe) and only that test will be run. our linter will reject this as invalid syntax so you can run karma start to run the karma tests independently.

[josetaira]

@icfantv Thanks for the info. Working on the unit tests now. Seems I did have to use grunt to create some templates (run grunt default before any tests). I'll add a commit for the test later on.

[icfantv]

@josetaira good deal.

[josetaira]

@icfantv @wesleycho tests committed.

[wesleycho]

This LGTM - thanks for the effort!