From 8eb54555ea7e26e6d589016bb6e72d6375a35d2d Mon Sep 17 00:00:00 2001
From: Andrew Lamb <andrew@nerdnetworks.org>
Date: Tue, 7 Oct 2025 13:08:04 -0400
Subject: [PATCH] Test refactor: avoid creating the same SchemaRef

---
 .../tests/physical_optimizer/test_utils.rs    | 52 ++++++++++++-------
 1 file changed, 32 insertions(+), 20 deletions(-)

diff --git a/datafusion/core/tests/physical_optimizer/test_utils.rs b/datafusion/core/tests/physical_optimizer/test_utils.rs
index b906dfa4b9ae..8ca33f3d4abb 100644
--- a/datafusion/core/tests/physical_optimizer/test_utils.rs
+++ b/datafusion/core/tests/physical_optimizer/test_utils.rs
@@ -19,7 +19,7 @@
 
 use std::any::Any;
 use std::fmt::Formatter;
-use std::sync::Arc;
+use std::sync::{Arc, LazyLock};
 
 use arrow::array::Int32Array;
 use arrow::compute::SortOptions;
@@ -142,37 +142,49 @@ pub(crate) fn parquet_exec_with_stats(file_size: u64) -> Arc<DataSourceExec> {
 }
 
 pub fn schema() -> SchemaRef {
-    Arc::new(Schema::new(vec![
-        Field::new("a", DataType::Int64, true),
-        Field::new("b", DataType::Int64, true),
-        Field::new("c", DataType::Int64, true),
-        Field::new("d", DataType::Int32, true),
-        Field::new("e", DataType::Boolean, true),
-    ]))
+    static SCHEMA: LazyLock<SchemaRef> = LazyLock::new(|| {
+        Arc::new(Schema::new(vec![
+            Field::new("a", DataType::Int64, true),
+            Field::new("b", DataType::Int64, true),
+            Field::new("c", DataType::Int64, true),
+            Field::new("d", DataType::Int32, true),
+            Field::new("e", DataType::Boolean, true),
+        ]))
+    });
+    Arc::clone(&SCHEMA)
 }
 
 pub fn create_test_schema() -> Result<SchemaRef> {
-    let nullable_column = Field::new("nullable_col", DataType::Int32, true);
-    let non_nullable_column = Field::new("non_nullable_col", DataType::Int32, false);
-    let schema = Arc::new(Schema::new(vec![nullable_column, non_nullable_column]));
+    static SCHEMA: LazyLock<SchemaRef> = LazyLock::new(|| {
+        let nullable_column = Field::new("nullable_col", DataType::Int32, true);
+        let non_nullable_column = Field::new("non_nullable_col", DataType::Int32, false);
+        Arc::new(Schema::new(vec![nullable_column, non_nullable_column]))
+    });
+    let schema = Arc::clone(&SCHEMA);
     Ok(schema)
 }
 
 pub fn create_test_schema2() -> Result<SchemaRef> {
-    let col_a = Field::new("col_a", DataType::Int32, true);
-    let col_b = Field::new("col_b", DataType::Int32, true);
-    let schema = Arc::new(Schema::new(vec![col_a, col_b]));
+    static SCHEMA: LazyLock<SchemaRef> = LazyLock::new(|| {
+        let col_a = Field::new("col_a", DataType::Int32, true);
+        let col_b = Field::new("col_b", DataType::Int32, true);
+        Arc::new(Schema::new(vec![col_a, col_b]))
+    });
+    let schema = Arc::clone(&SCHEMA);
     Ok(schema)
 }
 
 // Generate a schema which consists of 5 columns (a, b, c, d, e)
 pub fn create_test_schema3() -> Result<SchemaRef> {
-    let a = Field::new("a", DataType::Int32, true);
-    let b = Field::new("b", DataType::Int32, false);
-    let c = Field::new("c", DataType::Int32, true);
-    let d = Field::new("d", DataType::Int32, false);
-    let e = Field::new("e", DataType::Int32, false);
-    let schema = Arc::new(Schema::new(vec![a, b, c, d, e]));
+    static SCHEMA: LazyLock<SchemaRef> = LazyLock::new(|| {
+        let a = Field::new("a", DataType::Int32, true);
+        let b = Field::new("b", DataType::Int32, false);
+        let c = Field::new("c", DataType::Int32, true);
+        let d = Field::new("d", DataType::Int32, false);
+        let e = Field::new("e", DataType::Int32, false);
+        Arc::new(Schema::new(vec![a, b, c, d, e]))
+    });
+    let schema = Arc::clone(&SCHEMA);
     Ok(schema)
 }