1 files changed, 97 insertions, 0 deletions
diff --git a/users/tazjin/rlox/src/treewalk/interpreter/tests.rs b/users/tazjin/rlox/src/treewalk/interpreter/tests.rs
new file mode 100644
index 000000000000..2fc6f4fee978
--- /dev/null
+++ b/users/tazjin/rlox/src/treewalk/interpreter/tests.rs
@@ -0,0 +1,97 @@
+use super::*;
+
+/// Evaluate a code snippet, returning a value.
+fn parse_eval(code: &str) -> Value {
+    Interpreter::create()
+        .interpret(code.into())
+        .expect("could not interpret code")
+}
+
+#[test]
+fn test_if() {
+    let result = parse_eval(
+        r#"
+if (42 > 23)
+  "pass";
+else
+  "fail";
+"#,
+    );
+
+    assert_eq!(Value::Literal(Literal::String("pass".into())), result,);
+}
+
+#[test]
+fn test_scope() {
+    let result = parse_eval(
+        r#"
+var result = "";
+
+var a = "global a, ";
+var b = "global b, ";
+var c = "global c";
+
+{
+  var a = "outer a, ";
+  var b = "outer b, ";
+
+  {
+    var a = "inner a, ";
+    result = a + b + c;
+  }
+}
+"#,
+    );
+
+    assert_eq!(
+        Value::Literal(Literal::String("inner a, outer b, global c".into())),
+        result,
+    );
+}
+
+#[test]
+fn test_binary_operators() {
+    assert_eq!(Value::Literal(Literal::Number(42.0)), parse_eval("40 + 2;"));
+
+    assert_eq!(
+        Value::Literal(Literal::String("foobar".into())),
+        parse_eval("\"foo\" + \"bar\";")
+    );
+}
+
+#[test]
+fn test_functions() {
+    let result = parse_eval(
+        r#"
+fun add(a, b, c) {
+  a + b + c;
+}
+
+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);
+}