Allow using an unexported custom AbstractTestSet in @testset (#53212

)

Co-authored-by: Sukera <Seelengrab@users.noreply.github.com>

stdlib/Test/src/Test.jl

@@ -1731,7 +1731,8 @@ function parse_testset_args(args)
     options = :(Dict{Symbol, Any}())
     for arg in args
         # a standalone symbol is assumed to be the test set we should use
-        if isa(arg, Symbol)
+        # the same is true for a symbol that's not exported from a module
+        if isa(arg, Symbol) || Base.isexpr(arg, :.)
             testsettype = esc(arg)
         # a string is the description
         elseif isa(arg, AbstractString) || (isa(arg, Expr) && arg.head === :string)

stdlib/Test/test/runtests.jl

@@ -1586,3 +1586,21 @@ end
 @testset "Docstrings" begin
     @test isempty(Docs.undocumented_names(Test))
 end
+
+module CustomTestSetModule
+    using Test
+    struct CustomTestSet <: Test.AbstractTestSet
+        description::String
+    end
+    Test.record(::CustomTestSet, result) = result
+    Test.finish(cts::CustomTestSet) = cts
+end
+
+@testset "Unexported custom TestSet" begin
+    using .CustomTestSetModule
+    let res = @testset CustomTestSetModule.CustomTestSet begin
+                @test true
+            end
+        @test res isa CustomTestSetModule.CustomTestSet
+    end
+end