A test of an ember-cli-mirage setup where the library model hasMany books, but the book model does not belongTo library.
The issue is how to save a new book such that it is seen as attached to the library.
Assumes ember-cli 2.8.x.
npm install && bower install
ember serve
To try out the issue, go to:
http://localhost:4200/counties/library/1/book/new
and try to add a book.
When clicking the Add book button, the book is seen temporarily on the page, but once the library.save() method finishes, it disappears.
This seems to happen because the PATCH for the library does not update the books relationship to account for the new book.