[Xamarin.Android.Build.Tasks] don't call <ResolveAssemblyReference/> directly

[jonathanpeppers]

I found that we were invoking the <ResolveAssemblyReference/>
MSBuild task directly:

<ResolveAssemblyReference ...>
  <Output TaskParameter="SatelliteFiles" ItemName="_AndroidResolvedSatellitePaths"/>
</ResolveAssemblyReference>

What is weird about this, is that <ResolveAssemblyReference/> is
called twice during any Xamarin.Android build.

But the first call from MSBuild itself returns the exact same
assemblies we need here:

Task ResolveAssemblyReference
    ...
    OutputItems
    ...
        ReferenceSatellitePaths
            C:\src\weird-solutions\ClassLibrary1\bin\Debug\es\ClassLibrary3.resources.dll

In this example I added a Strings.resx and Strings.es.resx. The
satellite assembly contains the spanish translation.

It looks to me we can just remove our call to the
<ResolveAssemblyReference/> task, and use the public, built-in
@(ReferenceSatellitePaths) item group instead.

This worked, except for the in the case of
Mono.Android-Tests.csproj. It contains resx files in the main app
project, and these assemblies are not in @(ReferenceSatellitePaths).

Reviewing the code from MSBuild itself:

https://github.com/microsoft/msbuild/blob/master/src/Tasks/Microsoft.Common.CurrentVersion.targets#L4283-L4299

We can use the item transform to get satellite assemblies for the
current project:

@(IntermediateSatelliteAssembliesWithTargetPath->'$(OutDir)%(Culture)\$(TargetName).resources.dll')

There is not an item group for satellite assemblies in the current
project. However, we merely end up with:

<Target Name="_ResolveSatellitePaths" ...>
  <ItemGroup>
    <_AndroidResolvedSatellitePaths Include="@(ReferenceSatellitePaths)" />
    <_AndroidResolvedSatellitePaths Include="@(IntermediateSatelliteAssembliesWithTargetPath->'$(OutDir)%(Culture)\$(TargetName).resources.dll')" />
  </ItemGroup>
</Target>

This target will now take ~0ms instead of calling RAR.

In a build with no changes for the SmartHotel360 app (which includes a
netstandard project):

Before:
244 ms  ResolveAssemblyReference                   3 calls
After:
152 ms  ResolveAssemblyReference                   2 calls

This looks like a ~92ms savings to every build.

During the devloop, Build will run followed by Install. We will
have 2x savings to the devloop in this case: ~184ms.

[jonathanpeppers]

@dellis1972 do we have a test that has something like:

• Strings.resx
• Strings.es.resx

And verifies we can get the Spanish string at runtime?

[jonathanpeppers]

do we have a test that has something like...

Maybe this is exactly it: https://github.com/xamarin/xamarin-android/tree/master/tests/locales/Xamarin.Android.Locale-Tests

[jonathanpeppers]

The test failure is probably because I need to make some changes in monodroid:

System.InvalidOperationException : Satellite assembly resource lookup failed for resource 'AppString' from culture 'de-DE'.

Expected='App German'

Actual='App English'

https://github.com/xamarin/monodroid/search?q=_AndroidResolvedSatellitePaths&unscoped_q=_AndroidResolvedSatellitePaths

[dellis1972]

I suspect this is another "fix" we had to do for xbuild. So we probably don't need that call now.

[jonathanpeppers]

Ok, it looks like if the main app project has resx files, you also need to look at @(IntermediateSatelliteAssembliesWithTargetPath):

https://github.com/microsoft/msbuild/blob/1105f6db2fca58a45920ffb953a00aad2e93d794/src/Tasks/Microsoft.Common.CurrentVersion.targets#L4283-L4299

I may be able to keep the old target and item group, and just remove the direct call to <ResolveAssemblyReference/>.