Copy task should support copying a directory easily

[KirillOsenkov]

Copy task doesn't make it easy to copy the entire directory, it forces you to mess with wildcards etc. and it's gnarly

We should consider adding a new SourceFolder parameter on the Copy task that, if specified, pre-populates the SourceFiles with the entire directory. Of course SourceFolder and SourcesFiles should be mutually exclusive.

[jeffkl]

Microsoft.Build.Artifacts can do this, as a workaround. Still agree it would be nice for the copy to be built in and something like Microsoft.Build.Artifacts would just call it.

[KirillOsenkov]

Ugh, we should really fix this. Copying some files into a directory and preserving the directory structure is super painful.

[KirillOsenkov]

I'm imagining two new properties, SourceRoot and DestinationRoot, that when set, act as the corresponding roots, and the relative path from SourceRoot is preserved for each file.

[KirillOsenkov]

This way this won't be a breaking change.

[KirillOsenkov]

or maybe just SourceRoot and PreserveRelativePaths combined with the existing DestinationFolder.

[KirillOsenkov]

When I eventually come back here, here's how to do it:

<Project DefaultTargets="Copy">

  <PropertyGroup>
    <SourceDir>C:\temp\a</SourceDir>
    <DestinationDir>C:\temp\b</DestinationDir>
  </PropertyGroup>

  <Target Name="Copy">

    <!-- 
    PITFALL: if this runs during evaluation, the files might not exist on disk yet.
    So ensure this runs during execution and the glob is expanded immediately
    before the actual copy.
    -->
    <ItemGroup>
      <SourceFile Include="$(SourceDir)\**\*" />
      <DestinationFile Include="@(SourceFile->'$(DestinationDir)\%(RecursiveDir)%(Filename)%(Extension)')" />
    </ItemGroup>

    <Copy SourceFiles="@(SourceFile)"
          DestinationFiles="@(DestinationFile)"
          SkipUnchangedFiles="true" />
  </Target>

</Project>

[akoeplinger]

Another issue is that with the current approach you can't copy symbolic links from a source to a destination directory, the link gets resolved and the actual file copied instead of the symlink.

This will probably need to wait for BCL support (dotnet/runtime#24271) though.