SimpleTest: How to make multiple Ajax posts and then save the data?

Question

I have a form with AJAX buttons that add items to a list. To SimpleTest the form, I need to make the AJAX post:

$this->drupalPostAJAX(NULL, $edit, array('op' => 'Add Item Button'));

...then POST the resulting $edit object with the Save button.

$this->drupalPost('admin/structure/fms_report/create', $edit, t('Save'));

My question is, how do I get the resulting $edit object after the first AJAX POST happens?

Answer 1

On subsequent tests of a form that has already been loaded and posted, this call will submit the form to the same URL with the field values resulting from any previous activity:

$this->drupalPost(NULL, NULL, t('Save'));

The $edit argument is only to submit new field values. And, passing NULL for $path uses the currently loaded page. So, to test my AJAX button that adds items to the form:

$this->drupalGet('path/to/my/form');
$this->drupalPostAJAX(NULL, NULL, array('op' => 'Add Item Button'));
$this->drupalPostAJAX(NULL, NULL, array('op' => 'Add Item Button'));
$this->drupalPost(NULL, NULL, t('Save'));

I was able to verify after this that two items had been added to the form as expected.