src/derive.luau

@@ -1,5 +1,6 @@
 if not game then script = require "test/relative-string" end
 
+local throw = require(script.Parent.throw)
 local graph = require(script.Parent.graph)
 local create_node = graph.create_node
 local set_owner = graph.set_owner
@@ -8,8 +9,10 @@ local get_scope = graph.get_scope
 local open_scope = graph.open_scope
 local close_scope = graph.close_scope
 
+
 local function derive<T>(fn: () -> T): () -> T
     local owner = get_scope()
+    if not owner then throw("cannot derive in non-reactive scope") end
     assert(owner)
 
     local node = create_node((false :: any) :: T)