From 297a44ce56542cdc91b3a25ad99b1872b1ce0e9d Mon Sep 17 00:00:00 2001
From: greged93 <82421016+greged93@users.noreply.github.com>
Date: Mon, 8 Apr 2024 10:39:26 -0300
Subject: [PATCH] fix(katana-primitives): split_u256 (#1793)

fix split_u256
---
 crates/katana/primitives/src/utils/mod.rs | 22 ++++++++++++++++++++--
 1 file changed, 20 insertions(+), 2 deletions(-)

diff --git a/crates/katana/primitives/src/utils/mod.rs b/crates/katana/primitives/src/utils/mod.rs
index 3a1684749f..9c1591434b 100644
--- a/crates/katana/primitives/src/utils/mod.rs
+++ b/crates/katana/primitives/src/utils/mod.rs
@@ -9,7 +9,25 @@ pub mod transaction;
 /// The first element in the returned tuple is the low part, and the second element is the high
 /// part.
 pub fn split_u256(value: U256) -> (FieldElement, FieldElement) {
-    let low_u128: u128 = value.to::<u128>();
-    let high_u128: u128 = U256::from(value >> 128).to::<u128>();
+    let low_u128: u128 = (value & U256::from(u128::MAX)).to();
+    let high_u128: u128 = U256::from(value >> 128).to();
     (FieldElement::from(low_u128), FieldElement::from(high_u128))
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_split_u256() {
+        // Given
+        let value = U256::MAX;
+
+        // When
+        let (low, high) = split_u256(value);
+
+        // Then
+        assert_eq!(low, FieldElement::from(u128::MAX));
+        assert_eq!(high, FieldElement::from(u128::MAX));
+    }
+}