AnyHaveMetadataValue returns non boolean value when item group is empty

[pranavkm]

Consider:

    <Target Name="Foo">
        <ItemGroup>
            <Var Include="A" />
            <Var Include="B" />
        </ItemGroup>
        
        <PropertyGroup>
            <X>@(Var->AnyHaveMetadataValue('Identity', 'A'))</X>
        </PropertyGroup>
        
        <ItemGroup>
            <Var Remove="@(Var)" />
        </ItemGroup>
        
        <PropertyGroup>
            <Y>@(Var->AnyHaveMetadataValue('Identity', 'A'))</Y>
        </PropertyGroup>
        
        <Message Text="X=$(X) Y=$(Y)" Importance="High" />
    </Target>

Result:

X=true Y=

This makes using it much less elegant, as also the documentation a bit misleading.

[rainersigwald]

To change this I think we'd have to figure out why it's happening. Is it because we interpret @(Var), see that it's empty, and don't bother calling the item function? I suspect that's it. If so, we may not be able to change this since it's not clear whether the item functions can handle an empty-list input. But we'd need to debug in to figure out what's up.

[AraHaan]

it should be able to work in the item functions if you special case for when the lists are empty.

[Nirmal4G]

Yeah, I'm also hitting this in a similar fashion where I have a code like this to check for a default Program.{cs,vb,fs} file in the project.

<_ProgramSourceFileIsPresent>@(Compile->AnyHaveMetadataValue('Identity', 'Program$(DefaultLanguageSourceExtension)'))</_ProgramSourceFileIsPresent>

[Blackclaws]

Just hit something (probably) similar when trying to parse PackageVersion statements for a specific package. Is there any workaround for this?

[Blackclaws]

A working workaround that is rather inelegant but works for Conditions:

@(Var->WithMetadataValue('Identity', 'A')->Count()) >= 1