Don't remove detector

DifferentiationInterface/ext/DifferentiationInterfaceSymbolicsExt/DifferentiationInterfaceSymbolicsExt.jl

@@ -38,5 +38,6 @@ myvec(x::AbstractArray) = vec(x)
 
 include("onearg.jl")
 include("twoarg.jl")
+include("detector.jl")
 
 end

DifferentiationInterface/ext/DifferentiationInterfaceSymbolicsExt/detector.jl

@@ -0,0 +1,15 @@
+function ADTypes.jacobian_sparsity(f, x, ::DI.SymbolicsSparsityDetector)
+    y = similar(f(x))
+    f!(y, x) = copyto!(y, f(x))
+    return jacobian_sparsity(f!, y, x)
+end
+
+function ADTypes.jacobian_sparsity(f!, y, x, ::DI.SymbolicsSparsityDetector)
+    f!_vec(y_vec, x_vec) = f!(reshape(y_vec, size(y)), reshape(x_vec, size(x)))
+    return jacobian_sparsity(f!_vec, vec(y), vec(x))
+end
+
+function ADTypes.hessian_sparsity(f, x, ::DI.SymbolicsSparsityDetector)
+    f_vec(x_vec) = f(reshape(x_vec, size(x)))
+    return hessian_sparsity(f_vec, vec(x))
+end