[mono] [tests] Set error for mono_fullaot runtime tests when no suitable tests are found

[matouskozak]

Report MSBuild error when compiling selected runtime tests with mono_fullaot and no suitable tests are found.

Motivation

This can happen when locally building selected tests that are disabled in issues.targets. This causes:

1. Because TestExclusions contain the selected tests, TestScripts won't be created.

   runtime/src/tests/build.proj

   Line 112 in 980491d

   <TestScripts Include="@(AllTestScripts)" Exclude="@(TestExclusions)" />

2. This subsequently causes TestDirs to no exists, leading to enumarating all dlls on the disk (/**/*.dll) in

   runtime/src/tests/build.proj

   Line 127 in 980491d

   <TestsAndAssociatedAssemblies Include="%(TestDirs.Identity)/**/*.dll" Exclude="@(NoMonoAotAssemblyPaths)" />

Previous behavior

Build doesn't get stopped and the following warning is reported:

MSBUILD : warning MSB5029: The value "/**/*.dll" of the "Include" attribute in element <ItemGroup> in file "<RUNTIME_ROOT>runtime/src/tests/build.proj (122,37)" is a wildcard that results in enumerating all files on the drive, which was likely not intended. Check that referenced properties are always defined.

New behavior

Build gets canceled and error is reported: error : No tests found for Mono AOT compilation.

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Issue Details

---

Report MSBuild error when compiling selected runtime tests with mono_fullaot and no suitable tests are found.

Motivation

This can happen when locally building selected tests that are disabled in issues.targets. This causes:

1. Because TestExclusions contain the selected tests, TestScripts won't be created.

   runtime/src/tests/build.proj

   Line 112 in 980491d

   <TestScripts Include="@(AllTestScripts)" Exclude="@(TestExclusions)" />

2. This subsequently causes TestDirs to no exists, leading to enumarating all dlls on the disk (/**/*.dll) in

   runtime/src/tests/build.proj

   Line 127 in 980491d

   <TestsAndAssociatedAssemblies Include="%(TestDirs.Identity)/**/*.dll" Exclude="@(NoMonoAotAssemblyPaths)" />

Previous behavior

Build doesn't get stopped and the following warning is reported:

MSBUILD : warning MSB5029: The value "/**/*.dll" of the "Include" attribute in element <ItemGroup> in file "<RUNTIME_ROOT>runtime/src/tests/build.proj (122,37)" is a wildcard that results in enumerating all files on the drive, which was likely not intended. Check that referenced properties are always defined.

New behavior

Build gets canceled and error is reported: error : No tests found for Mono AOT compilation.

Author:	matouskozak
Assignees:	matouskozak
Labels:	area-Infrastructure-mono, needs-area-label
Milestone:	-

[ivanpovazan]

LGTM!

Only two nits:

1. Would it make sense to check on TestAssemblies instead, as there is already a condition filtering out paths that exist on line 115?
2. Maybe the error message can include additional information about tests exclusions, something like: ... Make sure that desired test cases are not excluded from AOT compilation