t.transformed test

datafusion/common/src/tree_node.rs

@@ -20,6 +20,8 @@
 
 use std::sync::Arc;
 
+use crate::utils::DataPtr;
+
 use crate::Result;
 
 /// If the function returns [`TreeNodeRecursion::Continue`], the normal execution of the
@@ -479,7 +481,17 @@ impl<T: DynTreeNode + ?Sized> TreeNode for Arc<T> {
         let children = self.arc_children();
         if !children.is_empty() {
             let t = children.into_iter().map_till_continue_and_collect(f)?;
+
             // TODO: once we trust `t.transformed` don't create new node if not necessary
+            let old_children = self.arc_children();
+            assert_eq!(
+                t.transformed,
+                t.data
+                    .iter()
+                    .zip(old_children.iter())
+                    .any(|(c1, c2)| !Arc::data_ptr_eq(c1, c2))
+            );
+
             let arc_self = Arc::clone(&self);
             self.with_new_arc_children(arc_self, t.data)
         } else {

datafusion/expr/src/tree_node/plan.rs

@@ -87,12 +87,15 @@ impl TreeNode for LogicalPlan {
             .iter()
             .map(|c| (*c).clone())
             .map_till_continue_and_collect(f)?;
+
         // TODO: once we trust `t.transformed` remove additional check
-        if old_children
+        let transformed = old_children
             .into_iter()
             .zip(t.data.iter())
-            .any(|(c1, c2)| c1 != c2)
-        {
+            .any(|(c1, c2)| c1 != c2);
+        assert_eq!(t.transformed, transformed);
+
+        if transformed {
             Ok(Transformed::new(
                 self.with_new_exprs(self.expressions(), t.data)?,
                 true,