test: fix children call in ReadOnlyNode

Author: MilesCranmer

src/Interfaces.jl

@@ -70,7 +70,9 @@ function _check_get_metadata(ex::AbstractExpression)
     new_ex = with_metadata(ex, get_metadata(ex))
     return new_ex == ex && new_ex isa typeof(ex)
 end
-function _check_get_tree(ex::AbstractExpression{T,N}) where {T,D,N<:AbstractExpressionNode{T,D}}
+function _check_get_tree(
+    ex::AbstractExpression{T,N}
+) where {T,D,N<:AbstractExpressionNode{T,D}}
     return get_tree(ex) isa N || get_tree(ex) isa AbstractReadOnlyNode{T,D,N}
 end
 function _check_get_operators(ex::AbstractExpression)

src/Node.jl

@@ -206,8 +206,9 @@ end
 @make_accessors Node
 @make_accessors GraphNode
 
+@inline children(node::AbstractNode) = node.children
 @inline function children(node::AbstractNode, ::Val{n}) where {n}
-    cs = node.children
+    cs = children(node)
     return ntuple(i -> cs[i][], Val(n))
 end
 

src/ReadOnlyNode.jl

@@ -1,7 +1,7 @@
 module ReadOnlyNodeModule
 
 using ..NodeModule: AbstractExpressionNode, Node
-import ..NodeModule: default_allocator, with_type_parameters, constructorof
+import ..NodeModule: default_allocator, with_type_parameters, constructorof, children
 
 abstract type AbstractReadOnlyNode{T,D,N<:AbstractExpressionNode{T,D}} <:
               AbstractExpressionNode{T,D} end
@@ -16,11 +16,14 @@ constructorof(::Type{<:ReadOnlyNode}) = ReadOnlyNode
 @inline function Base.getproperty(n::AbstractReadOnlyNode, s::Symbol)
     out = getproperty(getfield(n, :_inner), s)
     if out isa AbstractExpressionNode
-        return constructorof(typeof(n))(out)
+        return ReadOnlyNode(out)
     else
         return out
     end
 end
+@inline function children(node::AbstractReadOnlyNode)
+    return map(ReadOnlyNode, children(node))
+end
 function Base.setproperty!(::AbstractReadOnlyNode, ::Symbol, v)
     return error("Cannot set properties on a ReadOnlyNode")
 end