From df603dd4725b4157944fd72709d0f28832c1eada Mon Sep 17 00:00:00 2001
From: Liang-Chi Hsieh <viirya@gmail.com>
Date: Mon, 8 Apr 2024 22:33:25 -0700
Subject: [PATCH] fix: Fix wrong children expression order in IfExpr

---
 .../execution/datafusion/expressions/if_expr.rs    | 14 +++++++++++++-
 1 file changed, 13 insertions(+), 1 deletion(-)

diff --git a/core/src/execution/datafusion/expressions/if_expr.rs b/core/src/execution/datafusion/expressions/if_expr.rs
index 826f017c12..0af079c307 100644
--- a/core/src/execution/datafusion/expressions/if_expr.rs
+++ b/core/src/execution/datafusion/expressions/if_expr.rs
@@ -112,8 +112,8 @@ impl PhysicalExpr for IfExpr {
 
     fn children(&self) -> Vec<Arc<dyn PhysicalExpr>> {
         vec![
-            self.true_expr.clone(),
             self.if_expr.clone(),
+            self.true_expr.clone(),
             self.false_expr.clone(),
         ]
     }
@@ -218,4 +218,16 @@ mod tests {
 
         Ok(())
     }
+
+    #[test]
+    fn test_if_children() {
+        let if_expr = lit(true);
+        let true_expr = lit(123i32);
+        let false_expr = lit(999i32);
+
+        let expr = if_fn(if_expr, true_expr, false_expr);
+        let children = expr.unwrap().children();
+        assert_eq!(children.len(), 3);
+        assert_eq!(children[0].to_string(), "true");
+    }
 }