test that downstream packages aren't added

Author: oscardssmith

Project.toml

@@ -90,4 +90,4 @@ Unitful = "1986cc42-f94f-5a68-af5c-568840ba703d"
 Zygote = "e88e6eb3-aa80-5325-afca-941959d7151f"
 
 [targets]
-test = ["SafeTestsets", "Aqua", "FastBroadcast", "SparseArrays", "ForwardDiff", "NLsolve", "Pkg", "Test", "Unitful", "Random", "SciMLBase", "StaticArrays", "StructArrays", "Zygote", "Measurements"]
+test = ["Aqua", "FastBroadcast", "ForwardDiff", "Measurements", "NLsolve", "Pkg", "Random", "SafeTestsets", "SciMLBase", "SparseArrays", "StaticArrays", "StructArrays", "Test", "Unitful", "Zygote"]

test/qa.jl

@@ -1,4 +1,12 @@
-using RecursiveArrayTools, Aqua
+using RecursiveArrayTools, Aqua, Pkg
+
+# yes this is horrible, we'll fix it when Pkg or Base provides a decent API
+manifest = Pkg.Types.EnvCache().manifest
+# these are good sentinels to test whether someone has added a heavy SciML package to the test deps
+if haskey(manifest.deps, "NonlinearSolveBase") || haskey(manifest.deps, "DiffEqBase")
+    error("Don't put Downstream Packages in non Downstream CI")
+end
+
 @testset "Aqua" begin
     Aqua.find_persistent_tasks_deps(RecursiveArrayTools)
     Aqua.test_ambiguities(RecursiveArrayTools; recursive = false, broken = true)