[Feature Management]: Colon character allowed inside Feature Flag name if created through SetConfigurationSettingAsync

[Wonderjack996]

Hello Everyone!

I've noted that, through the endpoint SetConfigurationSettingAsync, it's possible to create a Feature Flag with the character colon (:) inside it's Name. Instead, through the Azure Portal it's possible to create a Feature Flag with the character colon only inside it's Key.

Is this behaviors intended? Or maybe it's a Bug?

Thanks.

[jimmyca15]

Hello Giacomo Savazzi (@Wonderjack996) This behavior is intended. There are languages that our library support that encounter issues when ':' is present in feature flag names. As such ':' was deemed an invalid character.

The reason it works with SetConfigurationSettingAsync is a side-effect of the fact that we store feature flags inside of configuration settings, which themselves allow any character. The feature flag content inside is not validated at the server level. The validation you see here is purely in the Portal UI.

[Wonderjack996]

Thank you so much Jimmy Campbell (@jimmyca15) 🙏

[jimmyca15]

After offline discussion we would like to track this as an improvement we can make going forward. Re-opening this issue for tracking purposes. No timeline established yet for this improvement.

[Wonderjack996]

Jimmy Campbell (@jimmyca15) I imagine the idea is to ensure that, even via the SetConfigurationSettingAsync method, it is not possible to create feature flags that contain the ':' character in their correct name? Also because I noticed (as you can see here https://github.com/microsoft/FeatureManagement-Dotnet/blob/772484c68e91ec9a75a43eb1cb42d4e9890b1c64/src/Microsoft.FeatureManagement/ConfigurationFeatureDefinitionProvider.cs#L92) that the Microsoft.FeatureManagement.FeatureManager class raises an exception if you call the IsEnabledAsync method with a feature flag name containing the :.

[jimmyca15]

I imagine the idea is to ensure that, even via the SetConfigurationSettingAsync method, it is not possible to create feature flags that contain the ':' character in their correct name?

The goal is to update feature management libraries in all languages to support ':', then validation to block ':' can be removed altogether.