tests

src/runtime.jl

@@ -27,3 +27,4 @@ accum(x::Tangent{T}, y::Tangent) where T = _tangent(T, accum(backing(x), backing
 
 _tangent(::Type{T}, z) where T = Tangent{T,typeof(z)}(z)
 _tangent(::Type, ::NamedTuple{()}) = NoTangent()
+_tangent(::Type, ::NamedTuple{<:Any, <:Tuple{Vararg{AbstractZero}}}) = NoTangent()

test/runtests.jl

@@ -257,13 +257,21 @@ z45, delta45 = frule_via_ad(DiffractorRuleConfig(), (0,1), x -> log(exp(x)), 2)
     @test tup_adj[2] ≈ [0.6666666666666666 0.5 0.4]
     @test tup_adj[2] isa Transpose
     @test gradient(x -> sum(atan.(x, (1,2,3))), Diagonal([4,5,6]))[1] isa Diagonal
+
+    @test gradient(x -> sum((y -> (x*y)).([1,2,3])), 4.0) == (6.0,)  # closure
 end
 
 @testset "broadcast, 2nd order" begin
+    @test gradient(x -> sum(gradient(x -> sum(x .^ 2 .+ x'), x)[1]), [1,2,3.0])[1] == [6,6,6]
+    @test gradient(x -> sum(gradient(x -> sum((x .+ 1) .* x .- x), x)[1]), [1,2,3.0])[1] == [2,2,2]
+    @test_broken gradient(x -> sum(gradient(x -> sum(x .* x ./ 2), x)[1]), [1,2,3.0])[1] == [1,1,1]
+
     @test_broken gradient(x -> sum(gradient(x -> sum(exp.(x)), x)[1]), [1,2,3])[1] ≈ exp.(1:3)  # MethodError: no method matching copy(::Nothing)
-    @test_broken gradient(x -> sum(gradient(x -> sum(exp.(x)), x)[1]), [1,2,3.0])[1] ≈ exp.(1:3)
+    @test_broken gradient(x -> sum(gradient(x -> sum(atan.(x, x')), x)[1]), [1,2,3.0])[1] ≈ [0,0,0]
     @test_broken gradient(x -> sum(gradient(x -> sum(transpose(x) .* x), x)[1]), [1,2,3]) == ([6,6,6],) # ERROR: (1, current_logger_for_env(std_level::Base.CoreLogging.LogLevel, group, _module) @ Base.CoreLogging logging.jl:500, :($(Expr(:meta, :noinline))))
     @test_broken gradient(x -> sum(gradient(x -> sum(transpose(x) ./ x.^2), x)[1]), [1,2,3])[1] ≈ [27.675925925925927, -0.824074074074074, -2.1018518518518516]
+
+    @test_broken gradient(z -> gradient(x -> sum((y -> (x^2*y)).([1,2,3])), z)[1], 5.0) == (12.0,)
 end
 
 # Higher order control flow not yet supported (https://github.com/JuliaDiff/Diffractor.jl/issues/24)