Description

In some circumstances the post title block well receive undefined as the title value from post:

Which results in an error when we try to access the length property:

This can be reproduced consistently when we insert a Query block and its placeholder state is rendered:

(notice the block errors in the above previews).

Here, we define title to have a default value of the empty string so we are not using undefined for input values and logic conditions expecting strings.

How has this been tested?

After this change we should experience no console errors when inserting a query block, and the previews should show the proper placeholder of "No Title" instead of the block errors shown above:

Also verify the post title block continues to work as expected in other flows.

Screenshots

Types of changes

Checklist:

• My code is tested.
• My code follows the WordPress code style.
• My code follows the accessibility standards.
• I've tested my changes with keyboard and screen readers.
• My code has proper inline documentation.
• I've included developer documentation if appropriate.
• I've updated all React Native files affected by any refactorings/renamings in this PR.