Allow passing in custom Scope to call_fn.

tests/call_fn.rs

@@ -1,5 +1,5 @@
 #![cfg(not(feature = "no_function"))]
-use rhai::{Engine, EvalAltResult, ParseErrorType, INT};
+use rhai::{Engine, EvalAltResult, ParseErrorType, Scope, INT};
 
 #[test]
 fn test_fn() -> Result<(), EvalAltResult> {
@@ -21,6 +21,9 @@ fn test_fn() -> Result<(), EvalAltResult> {
 #[test]
 fn test_call_fn() -> Result<(), EvalAltResult> {
     let mut engine = Engine::new();
+    let mut scope = Scope::new();
+
+    scope.push("foo", 42 as INT);
 
     let ast = engine.compile(
         r"
@@ -28,22 +31,22 @@ fn test_call_fn() -> Result<(), EvalAltResult> {
                 x + y
             }
             fn hello(x) {
-                x * 2
+                x * foo
             }
             fn hello() {
-                42
+                42 + foo
             }
         ",
     )?;
 
-    let r: i64 = engine.call_fn(&ast, "hello", (42 as INT, 123 as INT))?;
+    let r: i64 = engine.call_fn(&mut scope, &ast, "hello", (42 as INT, 123 as INT))?;
     assert_eq!(r, 165);
 
-    let r: i64 = engine.call_fn1(&ast, "hello", 123 as INT)?;
-    assert_eq!(r, 246);
+    let r: i64 = engine.call_fn1(&mut scope, &ast, "hello", 123 as INT)?;
+    assert_eq!(r, 5166);
 
-    let r: i64 = engine.call_fn0(&ast, "hello")?;
-    assert_eq!(r, 42);
+    let r: i64 = engine.call_fn0(&mut scope, &ast, "hello")?;
+    assert_eq!(r, 84);
 
     Ok(())
 }