Uniformize monorepo structure to OrdinaryDiffEq.jl canonical style

Convert the BoundaryValueDiffEq.jl monorepo to the canonical OrdinaryDiffEq.jl
structure: SafeTestsets/@safetestset group-dispatched tests, project-model
sublibrary CI, no ReTestItems and no test/Project.toml.

Tests (ReTestItems -> SafeTestsets):
- Rewrite every @testitem/@testsetup test file (root test/misc, test/wrappers,
  and all 6 lib/* sublibs) into plain @safetestset-includable test files
  (@testsetup module bodies hoisted to file top level; @testitem -> @testset;
  per-file `using <Package>`).
- Rewrite all 6 sublib test/runtests.jl to read BOUNDARYVALUEDIFFEQ_TEST_GROUP
  and @safetestset-include per group (Core/QA; FIRK uses EXPANDED/NESTED/QA).
- Rewrite root test/runtests.jl as a _detect_sublibrary_group dispatcher
  (activate lib/<X>, develop its [sources], set the sub group env, Pkg.test it;
  otherwise run the root's own Misc/Wrappers/QA @safetestset groups).
- Fold test/qa into the QA group: test/qa/runtests.jl -> test/qa/qa_tests.jl,
  delete test/qa/Project.toml.

Project.toml:
- Drop ReTestItems (and the now-unused Hwloc) from deps/extras/compat/targets
  across root + 6 sublibs; add SafeTestsets. Add JET to the root [extras]/
  [targets].test (folded from the deleted test/qa/Project.toml).
- Preserve the true [sources] path graph (leaf sublibs -> Core; root -> all 6).

Workflows:
- SublibraryCI.yml: sublibrary-project-tests.yml@v1 with
  group-env-name: BOUNDARYVALUEDIFFEQ_TEST_GROUP, check-bounds: auto.
- DowngradeSublibraries.yml: sublibrary-downgrade.yml@v1 with
  group-env-name/group-env-value Core, sibling+stdlib skip list, auto-discovery.
- CI.yml: new group-dispatched root CI (Misc/Wrappers/QA only — no sublib rows;
  sublibs are covered by SublibraryCI), replacing CI_BoundaryValueDiffEq.yml.
- Downgrade.yml: downgrade.yml@v1 with group: Misc and sibling+stdlib skip list.
- Delete QA.yml (folded into the root CI QA group).

test_groups.toml:
- Add lib/BoundaryValueDiffEqFIRK/test/test_groups.toml declaring its real
  EXPANDED/NESTED/QA groups (the default Core/QA discovery does not match FIRK).

No [compat] floors lowered; no tests skipped/broken/loosened.

Co-Authored-By: Chris Rackauckas <accounts@chrisrackauckas.com>
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: ChrisRackauckas

.github/workflows/CI.yml

@@ -0,0 +1,83 @@
+name: CI
+on:
+  pull_request:
+    branches:
+      - master
+  push:
+    branches:
+      - master
+concurrency:
+  # Skip intermediate builds: always.
+  # Cancel intermediate builds: only if it is a pull request build.
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: ${{ startsWith(github.ref, 'refs/pull/') }}
+jobs:
+  test:
+    permissions:
+      actions: write
+      contents: read
+    runs-on: ubuntu-latest
+    timeout-minutes: 120
+    strategy:
+      fail-fast: false
+      matrix:
+        # Root BoundaryValueDiffEq's own test groups only. The lib/* sublibraries
+        # are covered by SublibraryCI.yml (project model); do not double-test them
+        # through the root matrix.
+        group:
+          - Misc
+          - Wrappers
+          - QA
+        version:
+          - 'lts'
+          - '1.11'
+          - '1'
+          - 'pre'
+        exclude:
+          # QA (Aqua + JET) runs only on release Julia.
+          - group: QA
+            version: 'lts'
+          - group: QA
+            version: '1.11'
+          - group: QA
+            version: 'pre'
+    steps:
+      - uses: actions/checkout@v6
+      - uses: julia-actions/setup-julia@v3
+        with:
+          version: ${{ matrix.version }}
+      - uses: julia-actions/cache@v3
+      - name: Develop local path deps (Julia < 1.11)
+        shell: julia --color=yes --project=. {0}
+        run: |
+          using Pkg
+          if VERSION < v"1.11.0-DEV.0"
+            toml = Pkg.TOML.parsefile("Project.toml")
+            if haskey(toml, "sources")
+              specs = Pkg.PackageSpec[]
+              for (dep, spec) in toml["sources"]
+                if spec isa Dict && haskey(spec, "path") && isdir(spec["path"])
+                  @info "Developing" dep spec["path"]
+                  push!(specs, Pkg.PackageSpec(path=spec["path"]))
+                end
+              end
+              # Batch the develop call so Pkg resolves all path deps together.
+              isempty(specs) || Pkg.develop(specs)
+            end
+          end
+      - uses: julia-actions/julia-buildpkg@v1
+      - uses: julia-actions/julia-runtest@v1
+        with:
+          coverage: true
+          check_bounds: auto
+        env:
+          GROUP: ${{ matrix.group }}
+      - uses: julia-actions/julia-processcoverage@v1
+        with:
+          directories: src,ext
+      - uses: codecov/codecov-action@v6
+        with:
+          token: ${{ secrets.CODECOV_TOKEN }}
+          files: lcov.info
+          fail_ci_if_error: false
+          disable_safe_directory: true

.github/workflows/CI_BoundaryValueDiffEq.yml

@@ -18,5 +18,7 @@ jobs:
     uses: "SciML/.github/.github/workflows/downgrade.yml@v1"
     with:
       julia-version: "1.11"
-      skip: "Pkg,TOML"
+      group: "Misc"
+      # Skip stdlibs and the in-repo path-sourced sibling sublibraries.
+      skip: "Pkg,TOML,Statistics,LinearAlgebra,SparseArrays,InteractiveUtils,BoundaryValueDiffEqCore,BoundaryValueDiffEqMIRK,BoundaryValueDiffEqMIRKN,BoundaryValueDiffEqFIRK,BoundaryValueDiffEqShooting,BoundaryValueDiffEqAscher"
     secrets: "inherit"

.github/workflows/Downgrade.yml

@@ -23,4 +23,9 @@ jobs:
     secrets: "inherit"
     with:
       julia-version: "1.11"
-      skip: "Pkg,TOML"
+      # Skip stdlibs and the in-repo path-sourced sibling sublibraries (their
+      # compat bounds are irrelevant when developed locally). Every lib/*
+      # sublibrary is auto-discovered and downgrade-tested.
+      skip: "Pkg,TOML,Statistics,LinearAlgebra,SparseArrays,InteractiveUtils,BoundaryValueDiffEqCore,BoundaryValueDiffEqMIRK,BoundaryValueDiffEqMIRKN,BoundaryValueDiffEqFIRK,BoundaryValueDiffEqShooting,BoundaryValueDiffEqAscher"
+      group-env-name: "BOUNDARYVALUEDIFFEQ_TEST_GROUP"
+      group-env-value: "Core"

.github/workflows/DowngradeSublibraries.yml

@@ -19,4 +19,7 @@ concurrency:
 jobs:
   sublibraries:
     uses: "SciML/.github/.github/workflows/sublibrary-project-tests.yml@v1"
+    with:
+      group-env-name: BOUNDARYVALUEDIFFEQ_TEST_GROUP
+      check-bounds: auto
     secrets: "inherit"

.github/workflows/QA.yml

@@ -46,8 +46,8 @@ DiffEqDevTools = "2.48, 3"
 DifferentiationInterface = "0.7.13"
 FastClosures = "0.3.2"
 ForwardDiff = "0.10.38, 1"
-Hwloc = "3.3"
 InteractiveUtils = "<0.0.1, 1"
+JET = "0.9, 0.10, 0.11"
 LinearAlgebra = "1.10"
 LinearSolve = "3.12"
 NonlinearSolveBase = "2"
@@ -58,9 +58,9 @@ OrdinaryDiffEqTsit5 = "1.1, 2"
 OptimizationBase = "5"
 Pkg = "1.10.0"
 Random = "1.10"
-ReTestItems = "1.29"
 RecursiveArrayTools = "3.31.2, 4"
 Reexport = "1.2"
+SafeTestsets = "0.1.0"
 SciMLBase = "3"
 Sparspak = "0.3.11"
 StaticArrays = "1.9.8"
@@ -71,8 +71,8 @@ julia = "1.10"
 Aqua = "4c88cf16-eb10-579e-8560-4a9242c79595"
 DiffEqDevTools = "f3b72e0c-5b89-59e1-b016-84e28bfd966d"
 DifferentiationInterface = "a0c0ee7d-e4b9-4e03-894e-1c5f64a51d63"
-Hwloc = "0e44f5e4-bd66-52a0-8798-143a42290a1d"
 InteractiveUtils = "b77e0a4c-d291-57a0-90e8-8db25a27a240"
+JET = "c3a54625-cd67-489e-a8e7-0a5a0ff4e31b"
 LinearSolve = "7ed4a6bd-45f5-4d41-b270-4a48e9bafcae"
 NonlinearSolveBase = "be0214bd-f91f-a760-ac4e-3421ce2b2da0"
 NonlinearSolveFirstOrder = "5959db7a-ea39-4486-b5fe-2dd0bf03d60d"
@@ -82,11 +82,11 @@ OrdinaryDiffEqTsit5 = "b1df2697-797e-41e3-8120-5422d3b24e4a"
 OptimizationBase = "bca83a33-5cc9-4baa-983d-23429ab6bcbb"
 Pkg = "44cfe95a-1eb2-52ea-b672-e2afdf69b78f"
 Random = "9a3f8284-a2c9-5f02-9a11-845980a1fd5c"
-ReTestItems = "817f1d60-ba6b-4fd5-9520-3cf149f6a823"
 RecursiveArrayTools = "731186ca-8d62-57ce-b412-fbd966d074cd"
+SafeTestsets = "1bc83da4-3b8d-516f-aca4-4fe02f6d838f"
 Sparspak = "e56a9233-b9d6-4f03-8d0f-1825330902ac"
 StaticArrays = "90137ffa-7385-5640-81b9-e52037218182"
 Test = "8dfed614-e22c-5e08-85e1-65c5234f0b40"
 
 [targets]
-test = ["Aqua", "DiffEqDevTools", "DifferentiationInterface", "Hwloc", "InteractiveUtils", "LinearSolve", "NonlinearSolveFirstOrder", "ODEInterface", "OrdinaryDiffEqLowOrderRK", "OrdinaryDiffEqTsit5", "Pkg", "Random", "ReTestItems", "RecursiveArrayTools", "Sparspak", "StaticArrays", "Test", "OptimizationBase", "NonlinearSolveBase"]
+test = ["Aqua", "DiffEqDevTools", "DifferentiationInterface", "InteractiveUtils", "JET", "LinearSolve", "NonlinearSolveFirstOrder", "ODEInterface", "OrdinaryDiffEqLowOrderRK", "OrdinaryDiffEqTsit5", "Pkg", "Random", "RecursiveArrayTools", "SafeTestsets", "Sparspak", "StaticArrays", "Test", "OptimizationBase", "NonlinearSolveBase"]

.github/workflows/SublibraryCI.yml

@@ -19,6 +19,7 @@ SciMLBase = "0bca4576-84f4-4d90-8ffe-ffa030f20462"
 Setfield = "efcf1570-3423-57d1-acb7-fd33fddbac46"
 
 [compat]
+SafeTestsets = "0.1.0"
 ADTypes = "1.14"
 AlmostBlockDiagonals = "0.1.10"
 Aqua = "0.8"
@@ -28,12 +29,10 @@ DiffEqDevTools = "2.44, 3"
 DifferentiationInterface = "0.7"
 FastClosures = "0.3.2"
 ForwardDiff = "0.10.38, 1"
-Hwloc = "3"
 InteractiveUtils = "<0.0.1, 1"
 LinearAlgebra = "1.10"
 PreallocationTools = "0.4, 1"
 Random = "1.10"
-ReTestItems = "1.23.1"
 RecursiveArrayTools = "3.27.0, 4"
 Reexport = "1.2"
 SciMLBase = "3"
@@ -46,15 +45,14 @@ julia = "1.10"
 BoundaryValueDiffEqCore = {path = "../BoundaryValueDiffEqCore"}
 
 [extras]
+SafeTestsets = "1bc83da4-3b8d-516f-aca4-4fe02f6d838f"
 Aqua = "4c88cf16-eb10-579e-8560-4a9242c79595"
 DiffEqDevTools = "f3b72e0c-5b89-59e1-b016-84e28bfd966d"
-Hwloc = "0e44f5e4-bd66-52a0-8798-143a42290a1d"
 InteractiveUtils = "b77e0a4c-d291-57a0-90e8-8db25a27a240"
 Random = "9a3f8284-a2c9-5f02-9a11-845980a1fd5c"
-ReTestItems = "817f1d60-ba6b-4fd5-9520-3cf149f6a823"
 RecursiveArrayTools = "731186ca-8d62-57ce-b412-fbd966d074cd"
 StaticArrays = "90137ffa-7385-5640-81b9-e52037218182"
 Test = "8dfed614-e22c-5e08-85e1-65c5234f0b40"
 
 [targets]
-test = ["Aqua", "DiffEqDevTools", "Hwloc", "InteractiveUtils", "Random", "ReTestItems", "RecursiveArrayTools", "StaticArrays", "Test"]
+test = ["Aqua", "DiffEqDevTools", "InteractiveUtils", "Random", "RecursiveArrayTools", "StaticArrays", "Test", "SafeTestsets"]

Project.toml

@@ -1,5 +1,8 @@
+using BoundaryValueDiffEqAscher
+using Test
+
 # Standard test BVDAE problem from the URI M. ASCHER and RAYMOND J. SPITERI paper
-@testitem "Test Ascher solver on example problem 1" begin
+@testset "Test Ascher solver on example problem 1" begin
     using BoundaryValueDiffEqAscher, SciMLBase
     function f1!(du, u, p, t)
         e = 2.7
@@ -79,7 +82,7 @@ end
 ### Another BVDAE problem ###
 # Comes from "Boundary value problems for differential-algebraic equations"
 # by Leonid V. Kalachev and Robert E. O'Malley
-@testitem "Test Ascher solver on example problem 2" begin
+@testset "Test Ascher solver on example problem 2" begin
     using BoundaryValueDiffEqAscher, SciMLBase
 
     function f2!(du, u, p, t)
@@ -134,7 +137,7 @@ end
     end
 end
 
-@testitem "Test Ascher solver on example problem 3" begin
+@testset "Test Ascher solver on example problem 3" begin
     using BoundaryValueDiffEqAscher, SciMLBase
     function f3!(du, u, p, t)
         du[1] = -u[3]

lib/BoundaryValueDiffEqAscher/Project.toml

@@ -1,4 +1,7 @@
-@testitem "Quality Assurance" tags = [:qa] begin
+using BoundaryValueDiffEqAscher
+using Test
+
+@testset "Quality Assurance" begin
     using Aqua
 
     Aqua.test_all(BoundaryValueDiffEqAscher)