accommodate closed-when-empty holdings accordions

description

Click closed/empty holdings accordions to reveal the "New item" button

details

As of UIIN-827, inventory accordions are now closed when empty, thus hiding the "new item" button on a newly-created holdings record. Integration tests that create new item records now fail as a result. Any test that creates a new item record from a new holdings record must therefore be updated to click the holdings accordion to expand it in order to reveal the "New item" button.

The following integration tests fail as a direct result of this change:

• stripes-core / exercise
• stripes-core / many-items
• stripes-core / loan-renewal
• stripes-core / new-request
• checkout / error-messages
• inventory / new-title

Most of these can probably be repaired by fixing stripes-testing/helpers.js#createNInventory with the exception of inventory / new-title.

The instance-record DOM hierarchy contains the following useful elements, notably aria-expanded="false":

<section
  class="accordion---3AcH2 hasSeparator---1vtJ1">
  <button 
    type="button" 
    class="defaultCollapseButton---1NLIE interactionStylesControl---2Hfae" 
    aria-expanded="false" 
    role="tab">

CC: vladyslav_velytskyi, taras_tkachenko