[Bug Report]: Storage Account Bicep Linting - Warning BCP329

[russellds]

Describe the bug

Getting the following linting warning when using the Storage Account module:

WARNING: ...\modules\storage\storage-account\blob-service\main.bicep(82,24) : Warning BCP329: The provided value can be as small as 0 and may be too small to assign to a target with a configured minimum of 1.

To reproduce

Use Storage Account bicep module to deploy a storage account.

Code snippet

No response

Relevant log output

No response

[AlexanderSehr]

Hey Russell Slater (@russellds),
thanks for brining this up. This seems to be an issue with this line:

retentionInDays: changeFeedEnabled == true ? (changeFeedRetentionInDays != 0 ? changeFeedRetentionInDays : null) : null

in which retentionInDays must be larger than 0, yet the parameter changeFeedRetentionInDays can be 0.

As you may already figured by looking at the above if else statement, this is actually a false-positive. If changeFeedRetentionInDays were to be 0, Bicep would actually set the value to null not 0.

I can only assume this was implemented this way because originally, it wasn't able to specify optional parameter in Bicep without also providing a default (in this case 0).

Now that nullable types are available, the parameter could change to something like param changeFeedRetentionInDays int? and the logic in the template could change to

param changeFeedRetentionInDays int?

(...)
retentionInDays: changeFeedRetentionInDays
(...)