Deprecation Guide for Using @guid and @item as key in {{each}}

As of 1.13.2 you should not use key='@guid' or key='@item' in the {{each}} helper. It is documented in 1.13 that you can use these special values to uniquely identify each array entry so that the view code could more efficiently re-render the display of the list.

This process was simplified as part of a bugfix, where the key now implicitly defaults to @identity, which will pick either a guid or an item identifier based on type of each array entry. Therefore, providing the key attribute is no longer required for re-render optimizations.

Applications should replace instances of:

{{#each people key='@guid' as |person|}}
...
{{/each}}

and

{{#each people key='@item' as |person|}}
...
{{/each}}

with

{{#each people as |person|}}
...
{{/each}}