From 38b373bf0b78bfe3b332c9fbb115e2ce3e9768d0 Mon Sep 17 00:00:00 2001
From: mlugg <mlugg@mlugg.co.uk>
Date: Fri, 17 Nov 2023 04:46:23 +0000
Subject: [PATCH] cases: add compile error test for never-mutated local
 variable

---
 .../compile_errors/var_never_mutated.zig      | 28 +++++++++++++++++++
 1 file changed, 28 insertions(+)
 create mode 100644 test/cases/compile_errors/var_never_mutated.zig

diff --git a/test/cases/compile_errors/var_never_mutated.zig b/test/cases/compile_errors/var_never_mutated.zig
new file mode 100644
index 0000000000..e6594e9344
--- /dev/null
+++ b/test/cases/compile_errors/var_never_mutated.zig
@@ -0,0 +1,28 @@
+fn entry0() void {
+    var a: u32 = 1 + 2;
+    _ = a;
+}
+
+fn entry1() void {
+    const a: u32 = 1;
+    const b: u32 = 2;
+    var c = a + b;
+    const d = c;
+    _ = d;
+}
+
+fn entry2() void {
+    var a: u32 = 123;
+    foo(a);
+}
+
+fn foo(_: u32) void {}
+
+// error
+//
+// :2:9: error: local variable is never mutated
+// :2:9: note: consider using 'const'
+// :9:9: error: local variable is never mutated
+// :9:9: note: consider using 'const'
+// :15:9: error: local variable is never mutated
+// :15:9: note: consider using 'const'