Warning: Undefined variable $max in Drupal\custom_field\Plugin\Field\FieldType\CustomItem::generateSampleValue()

This makes sense and simplifies. Let me do my further due diligence and i'll get it merged. Thanks for the patch!

@apmsooner You could create a hidden test module that sets via config a custom field with all the available datatypes. The test module could be used for quickly getting an instance of a custom field available and may be used for automated tests.

@jrockowitz, tested your patch and modified it as theres some differences between decimal/float around scale so elected to keep them separate. I revisited the core field types for both of these and matched the logic more closely to account for missing/non-numeric properties. Tested this out in variety of scenarios and works now as expected without error. Agree a test module will be helpful and will work toward that but for now this will get us past the error. Let me know if this works for you or have further input?

Merged to dev.

Thank you for improving the patch and merging it.

Automatically closed - issue fixed for 2 weeks with no activity.