From d9e9c28889e65ba8f960909738e75195998f67b0 Mon Sep 17 00:00:00 2001
From: Brendan Hansknecht <brendan.hansknecht@gmail.com>
Date: Sun, 27 Feb 2022 00:45:51 -0800
Subject: [PATCH] add error test case

---
 compiler/can/src/builtins.rs      |  2 +-
 compiler/test_gen/src/gen_list.rs | 17 +++++++++++++++++
 2 files changed, 18 insertions(+), 1 deletion(-)

diff --git a/compiler/can/src/builtins.rs b/compiler/can/src/builtins.rs
index 550c7d0d0f..dbc5063359 100644
--- a/compiler/can/src/builtins.rs
+++ b/compiler/can/src/builtins.rs
@@ -2326,7 +2326,7 @@ fn list_replace(symbol: Symbol, var_store: &mut VarStore) -> Def {
     // Otherwise, return the list unmodified.
     let body = If {
         cond_var: bool_var,
-        branch_var: var_store.fresh(),
+        branch_var: ret_result_var,
         branches: vec![(
             // if-condition
             no_region(
diff --git a/compiler/test_gen/src/gen_list.rs b/compiler/test_gen/src/gen_list.rs
index ba4cce5362..ac34090e7d 100644
--- a/compiler/test_gen/src/gen_list.rs
+++ b/compiler/test_gen/src/gen_list.rs
@@ -1780,6 +1780,23 @@ fn replace_unique_int_list() {
     );
 }
 
+#[test]
+#[cfg(any(feature = "gen-llvm"))]
+fn replace_unique_int_list_out_of_bounds() {
+    assert_evals_to!(
+        indoc!(
+            r#"
+                result = List.replace [ 12, 9, 7, 1, 5 ] 5 33
+                when result is
+                    Ok {value} -> value
+                    Err OutOfBounds -> -1 
+            "#
+        ),
+        -1,
+        i64
+    );
+}
+
 #[test]
 #[cfg(any(feature = "gen-llvm"))]
 fn replace_unique_int_list_get_old_value() {