feat(tazjin/rlox): Implement support for closures r/2109

Change-Id: I0ffc810807a1a6ec90455a4f2d2bd977833005bd
Reviewed-on: https://cl.tvl.fyi/c/depot/+/2396
Reviewed-by: tazjin <mail@tazj.in>
Tested-by: BuildkiteCI

1 files changed, 22 insertions, 0 deletions

diff --git a/users/tazjin/rlox/src/interpreter/tests.rs b/users/tazjin/rlox/src/interpreter/tests.rs
index 5bc9f0a0a4..875116593e 100644
--- a/users/tazjin/rlox/src/interpreter/tests.rs
+++ b/users/tazjin/rlox/src/interpreter/tests.rs
@@ -76,3 +76,25 @@ add(1, 2, 3);
 
     assert_eq!(Value::Literal(Literal::Number(6.0)), result);
 }
+
+#[test]
+fn test_closure() {
+    let result = parse_eval(
+        r#"
+fun makeCounter() {
+  var i = 0;
+  fun count() {
+    i = i + 1;
+  }
+
+  return count;
+}
+
+var counter = makeCounter();
+counter(); // "1".
+counter(); // "2".
+"#,
+    );
+
+    assert_eq!(Value::Literal(Literal::Number(2.0)), result);
+}