allow stdlibs to run their tests in parallel

this is done by creating a file `tests` in the `test` folder
that lists the different files with tests (excluding ".jl").
If this file does not exist, we fall back to using the runtests.jl file

stdlib/LinearAlgebra/test/runtests.jl

@@ -1,24 +1,5 @@
 # This file is a part of Julia. License is MIT: https://julialang.org/license
 
-include("triangular.jl")
-include("qr.jl")
-include("dense.jl")
-include("matmul.jl")
-include("schur.jl")
-include("special.jl")
-include("eigen.jl")
-include("bunchkaufman.jl")
-include("svd.jl")
-include("lapack.jl")
-include("tridiag.jl")
-include("bidiag.jl")
-include("diagonal.jl")
-include("cholesky.jl")
-include("lu.jl")
-include("symmetric.jl")
-include("generic.jl")
-include("uniformscaling.jl")
-include("lq.jl")
-include("hessenberg.jl")
-include("blas.jl")
-include("adjtrans.jl")
+for file in readlines(joinpath(@__DIR__, "tests")
+    include(file * ".jl")
+end

stdlib/LinearAlgebra/test/tests

@@ -0,0 +1,22 @@
+triangular
+qr
+dense
+matmul
+schur
+special
+eigen
+bunchkaufman
+svd
+lapack
+tridiag
+bidiag
+diagonal
+cholesky
+lu
+symmetric
+generic
+uniformscaling
+lq
+hessenberg
+blas
+adjtrans

stdlib/SparseArrays/test/higherorderfns.jl

@@ -4,6 +4,11 @@
 # base/sparse/higherorderfns.jl, particularly map[!]/broadcast[!] for SparseVectors and
 # SparseMatrixCSCs at present.
 
+module HigherOrderFnsTests
+
+using Test
+using SparseArrays
+using LinearAlgebra
 using Random
 
 @testset "map[!] implementation specialized for a single (input) sparse vector/matrix" begin
@@ -548,3 +553,5 @@ end
     @test spzeros(1,2) .+ spzeros(0,1) == zeros(0,2)
     @test spzeros(1,2) .* spzeros(0,1) == zeros(0,2)
 end
+
+end # module

stdlib/SparseArrays/test/runtests.jl

@@ -1,8 +1,5 @@
 # This file is a part of Julia. License is MIT: https://julialang.org/license
 
-using Test, SparseArrays
-using LinearAlgebra
-
-include("higherorderfns.jl")
-include("sparse.jl")
-include("sparsevector.jl")
+for file in readlines(joinpath(@__DIR__, "tests")
+    include(file * ".jl")
+end

stdlib/SparseArrays/test/sparse.jl

@@ -1,6 +1,10 @@
 # This file is a part of Julia. License is MIT: https://julialang.org/license
 
-using LinearAlgebra: mul!, ldiv!, rdiv!
+module SparseTests
+
+using Test
+using SparseArrays
+using LinearAlgebra
 using Base.Printf: @printf
 using Random
 
@@ -2208,4 +2212,6 @@ end
 @testset "findnz on non-sparse arrays" begin
     @test findnz([0 1; 0 2]) == ([1, 2], [2, 2], [1, 2])
     @test findnz(BitArray([false true; false true])) == ([1, 2], [2, 2], trues(2))
-end
+end
+
+end # module

stdlib/SparseArrays/test/sparsevector.jl

@@ -1,5 +1,9 @@
 # This file is a part of Julia. License is MIT: https://julialang.org/license
 
+module SparseVectorTests
+
+using Test
+using SparseArrays
 using LinearAlgebra
 using Random
 
@@ -1264,3 +1268,5 @@ end
               LinearAlgebra.lowrankupdate!(Matrix(1.0*I, n, n), fill(1.0, n), Ajview)
     end
 end
+
+end # module

stdlib/SparseArrays/test/tests

@@ -0,0 +1,3 @@
+higherorderfns
+sparse
+sparsevector

test/choosetests.jl

@@ -146,6 +146,20 @@ function choosetests(choices = [])
         prepend!(tests, STDLIBS)
     end
 
+    new_tests = String[]
+    for test in tests
+        if test in STDLIBS
+            testfile = joinpath(STDLIB_DIR, test, "test", "tests")
+            if isfile(testfile)
+                prepend!(new_tests, (test * "/") .* readlines(testfile))
+            else
+                push!(new_tests, test * "/runtests")
+            end
+        end
+    end
+    filter!(x -> (x != "stdlib" && !(x in STDLIBS)) , tests)
+    prepend!(tests, new_tests)
+
     # do ambiguous first to avoid failing if ambiguities are introduced by other tests
     if "ambiguous" in skip_tests
         filter!(x -> x != "ambiguous", tests)

test/runtests.jl

@@ -18,8 +18,9 @@ else
 end
 
 function test_path(test)
-    if test in STDLIBS
-        return joinpath(STDLIB_DIR, test, "test", "runtests")
+    t = split(test, '/')
+    if length(t) == 2 && t[1] in STDLIBS
+        return joinpath(STDLIB_DIR, t[1], "test", t[2])
     else
         return joinpath(@__DIR__, test)
     end