Add test for call_fn_raw.

tests/call_fn.rs

@@ -69,6 +69,36 @@ fn test_call_fn() -> Result<(), Box<EvalAltResult>> {
     Ok(())
 }
 
+#[test]
+fn test_call_fn_scope() -> Result<(), Box<EvalAltResult>> {
+    let engine = Engine::new();
+    let mut scope = Scope::new();
+
+    let ast = engine.compile(
+        "
+            fn foo(x) {
+                let hello = 42;
+                bar + hello + x
+            }
+
+            let bar = 123;
+        ",
+    )?;
+
+    for _ in 0..50 {
+        assert_eq!(
+            engine
+                .call_fn_raw(&mut scope, &ast, true, false, "foo", None, [Dynamic::THREE])?
+                .as_int()?,
+            168
+        );
+    }
+
+    assert_eq!(scope.len(), 100);
+
+    Ok(())
+}
+
 struct Options {
     pub foo: bool,
     pub bar: String,