add test for #43 (#48)

Author: simeonschaub

Project.toml

@@ -23,9 +23,10 @@ julia = "1.7"
 
 [extras]
 ForwardDiff = "f6369f11-7733-5829-9624-2563aa707210"
+LinearAlgebra = "37e2e46d-f89d-539d-b4ee-838fcccc9c8e"
 Random = "9a3f8284-a2c9-5f02-9a11-845980a1fd5c"
 Symbolics = "0c5d862f-8b57-4792-8d23-62f2024744c7"
 Test = "8dfed614-e22c-5e08-85e1-65c5234f0b40"
 
 [targets]
-test = ["Test", "Symbolics", "ForwardDiff", "Random"]
+test = ["Test", "ForwardDiff", "LinearAlgebra", "Random", "Symbolics"]

test/runtests.jl

@@ -4,6 +4,7 @@ using ChainRules
 using ChainRulesCore
 using ChainRules: ZeroTangent, NoTangent
 using Symbolics
+using LinearAlgebra
 
 using Test
 
@@ -195,4 +196,9 @@ end
 # Issue #40 - Symbol type parameters not properly quoted
 @test Diffractor.∂⃖recurse{1}()(Val{:transformations})[1] === Val{:transformations}()
 
+# PR #43
+loss(res, z, w) = sum(res.U * Diagonal(res.S) * res.V) + sum(res.S .* w)
+x = rand(10, 10)
+@test Diffractor.gradient(x->loss(svd(x), x[:,1], x[:,2]), x) isa Tuple{Matrix{Float64}}
+
 include("pinn.jl")