also test deep nested StructArray's broadcast.

Author: N5N3

test/runtests.jl

@@ -1193,6 +1193,8 @@ Base.BroadcastStyle(::Broadcast.ArrayStyle{MyArray2}, S::Broadcast.DefaultArrayS
 
     @test identity.(StructArray(x=StructArray(a=1:3)))::StructArray == [(x=(a=1,),), (x=(a=2,),), (x=(a=3,),)]
     @test (x -> x.x.a).(StructArray(x=StructArray(a=1:3))) == [1, 2, 3]
+    @test identity.(StructArray(x=StructArray(x=StructArray(a=1:3))))::StructArray == [(x=(x=(a=1,),),), (x=(x=(a=2,),),), (x=(x=(a=3,),),)]
+    @test (x -> x.x.x.a).(StructArray(x=StructArray(x=StructArray(a=1:3)))) == [1, 2, 3]
 
     @testset "ambiguity check" begin
         function _test(a, b, c)