From ef1ade1f05996b7292dabd7fcb7d26536f900003 Mon Sep 17 00:00:00 2001
From: Jefffrey <jeffrey.vo.australia@gmail.com>
Date: Fri, 19 Sep 2025 21:58:12 +0900
Subject: [PATCH] Support FixedSizeList for array_slice via coercion to List

---
 datafusion/functions-nested/src/extract.rs   | 24 ++++----------------
 datafusion/sqllogictest/test_files/array.slt | 12 ++++++++++
 2 files changed, 16 insertions(+), 20 deletions(-)

diff --git a/datafusion/functions-nested/src/extract.rs b/datafusion/functions-nested/src/extract.rs
index a64fd1426433..7aad167f1da4 100644
--- a/datafusion/functions-nested/src/extract.rs
+++ b/datafusion/functions-nested/src/extract.rs
@@ -337,7 +337,7 @@ impl ArraySlice {
                             ArrayFunctionArgument::Index,
                             ArrayFunctionArgument::Index,
                         ],
-                        array_coercion: None,
+                        array_coercion: Some(ListCoercion::FixedSizedListToList),
                     }),
                     TypeSignature::ArraySignature(ArrayFunctionSignature::Array {
                         arguments: vec![
@@ -346,7 +346,7 @@ impl ArraySlice {
                             ArrayFunctionArgument::Index,
                             ArrayFunctionArgument::Index,
                         ],
-                        array_coercion: None,
+                        array_coercion: Some(ListCoercion::FixedSizedListToList),
                     }),
                 ],
                 Volatility::Immutable,
@@ -672,15 +672,7 @@ pub(super) struct ArrayPopFront {
 impl ArrayPopFront {
     pub fn new() -> Self {
         Self {
-            signature: Signature {
-                type_signature: TypeSignature::ArraySignature(
-                    ArrayFunctionSignature::Array {
-                        arguments: vec![ArrayFunctionArgument::Array],
-                        array_coercion: Some(ListCoercion::FixedSizedListToList),
-                    },
-                ),
-                volatility: Volatility::Immutable,
-            },
+            signature: Signature::array(Volatility::Immutable),
             aliases: vec![String::from("list_pop_front")],
         }
     }
@@ -776,15 +768,7 @@ pub(super) struct ArrayPopBack {
 impl ArrayPopBack {
     pub fn new() -> Self {
         Self {
-            signature: Signature {
-                type_signature: TypeSignature::ArraySignature(
-                    ArrayFunctionSignature::Array {
-                        arguments: vec![ArrayFunctionArgument::Array],
-                        array_coercion: Some(ListCoercion::FixedSizedListToList),
-                    },
-                ),
-                volatility: Volatility::Immutable,
-            },
+            signature: Signature::array(Volatility::Immutable),
             aliases: vec![String::from("list_pop_back")],
         }
     }
diff --git a/datafusion/sqllogictest/test_files/array.slt b/datafusion/sqllogictest/test_files/array.slt
index e72049171291..b1b08773a837 100644
--- a/datafusion/sqllogictest/test_files/array.slt
+++ b/datafusion/sqllogictest/test_files/array.slt
@@ -1938,6 +1938,12 @@ select array_slice(arrow_cast(make_array(1, 2, 3, 4, 5), 'LargeList(Int64)'), 2,
 ----
 [2, 3, 4] [h, e]
 
+query ??
+select array_slice(arrow_cast(make_array(1, 2, 3, 4, 5), 'FixedSizeList(5, Int64)'), 2, 4),
+       array_slice(arrow_cast(make_array('h', 'e', 'l', 'l', 'o'), 'FixedSizeList(5, Utf8)'), 1, 2);
+----
+[2, 3, 4] [h, e]
+
 # array_slice scalar function #2 (with positive indexes; full array)
 query ??
 select array_slice(make_array(1, 2, 3, 4, 5), 0, 6), array_slice(make_array('h', 'e', 'l', 'l', 'o'), 0, 5);
@@ -1949,6 +1955,12 @@ select array_slice(arrow_cast(make_array(1, 2, 3, 4, 5), 'LargeList(Int64)'), 0,
 ----
 [1, 2, 3, 4, 5] [h, e, l, l, o]
 
+query ??
+select array_slice(arrow_cast(make_array(1, 2, 3, 4, 5), 'FixedSizeList(5, Int64)'), 0, 6),
+       array_slice(arrow_cast(make_array('h', 'e', 'l', 'l', 'o'), 'FixedSizeList(5, Utf8)'), 0, 5);
+----
+[1, 2, 3, 4, 5] [h, e, l, l, o]
+
 # array_slice scalar function #3 (with positive indexes; first index = second index)
 query ??
 select array_slice(make_array(1, 2, 3, 4, 5), 4, 4), array_slice(make_array('h', 'e', 'l', 'l', 'o'), 3, 3);