fix: VoA stack

Author: AayushSabharwal

src/vector_of_array.jl

@@ -499,7 +499,7 @@ function Base.append!(VA::AbstractVectorOfArray{T, N},
 end
 
 function Base.stack(VA::AbstractVectorOfArray; dims = :)
-    stack(VA.u; dims)
+    stack(stack.(VA.u); dims)
 end
 
 # AbstractArray methods
@@ -633,7 +633,7 @@ function Base.convert(::Type{Array}, VA::AbstractVectorOfArray)
     if !allequal(size.(VA.u))
         error("Can only convert non-ragged VectorOfArray to Array")
     end
-    return stack(VA.u)
+    return stack(VA)
 end
 
 # statistics

test/interface_tests.jl

@@ -109,6 +109,9 @@ end
 @test stack(testva) == [1 4 7; 2 5 8; 3 6 9]
 @test stack(testva; dims = 1) == [1 2 3; 4 5 6; 7 8 9]
 
+testva = VectorOfArray([VectorOfArray([ones(2,2), 2ones(2, 2)]), 3ones(2, 2, 2)])
+@test stack(testva) == [1.0 1.0; 1.0 1.0;;; 2.0 2.0; 2.0 2.0;;;; 3.0 3.0; 3.0;;; 3.0 3.0; 3.0 3.0]
+
 # convert array from VectorOfArray/DiffEqArray
 t = 1:8
 recs = [rand(10, 7) for i in 1:8]