`Get-DscProperty`: Add optional switch parameter `IgnoreZeroEnumValue`

[johlju]

Problem description

When a calss-based DSC resource is built using the pattern that DscResource.Base provides it is an option to set the flag FeatureOptionalEnums which allows an optional DSC property to use an Enum type. The enum value 0 is then ignored and considered to be equivalent to parameter set to $null. The command Get-DscProperty does not handle this and will return a property with the value 0 as a property that is set. 0 means user did not provide a value using the previous mentioned pattern and should have been ignored or seen as a property that is not set.

Verbose logs

not available

How to reproduce

Call Get-DscProperty with a property with an enum type and the value set to 0.

Expected behavior

Possible to to tell the command to ignore the enums with a value of zero.

Current behavior

Command will always return the propetty even if it is set to zero.

Suggested solution

Add an optional property IgnoreZeroEnumValue that will check if the datatype is enum and then if the value is zero, it will be skipped/ignored the same way as the command skips/ignores null value properties.

Operating system the target node is running

n/a

PowerShell version and build the target node is running

n/a

Module version used

Latest

[johlju]

Suggestion mentioned in PR dsccommunity/SqlServerDsc#2083 (review) is to move Clear-ZeroedEnumPropertyValue
to this module. Then the function might be used to remove the enum values set to 0 if the optional parameter is specified. But before the move it should be cosidered if it can be actually used by commands. 🤔

[dan-hughes]

I don't know if there is going to be the need for Clear-ZeroedEnumPropertyValue to be public.

I like a switch being added to Get-DscProperty, it's likely to be a multi-step change though.

1. Add Clear-ZeroedEnumPropertyValue as a Private function to this module.
2. Add IgnoreZeroEnumValue parameter to Get-DscProperty.
3. Release DscResource.Common.
4. Update DscResource.Base to use updated Get-DscProperty, remove Clear-ZeroedEnumPropertyValue.
5. Release DscResource.Base.

[johlju]

That sounds like a good plan.

[johlju]

I will release this later today.

[johlju]

It is released now.