Add eval test.

tests/eval.rs

@@ -0,0 +1,61 @@
+use rhai::{Engine, EvalAltResult, Scope, INT};
+
+#[test]
+fn test_eval() -> Result<(), EvalAltResult> {
+    let mut engine = Engine::new();
+    let mut scope = Scope::new();
+
+    assert_eq!(
+        engine.eval_with_scope::<INT>(
+            &mut scope,
+            r#"
+                let x = 10;
+
+                fn foo(x) { x += 12; x }
+
+                let script = "let y = x;";      // build a script
+                script +=    "y += foo(y);";
+                script +=    "x + y";
+
+                eval(script)
+    "#
+        )?,
+        42
+    );
+
+    assert_eq!(
+        scope
+            .get_value::<INT>("x")
+            .expect("variable x should exist"),
+        10
+    );
+
+    assert_eq!(
+        scope
+            .get_value::<INT>("y")
+            .expect("variable y should exist"),
+        32
+    );
+
+    assert!(!scope.contains("z"));
+
+    Ok(())
+}
+
+#[test]
+fn test_eval_override() -> Result<(), EvalAltResult> {
+    let mut engine = Engine::new();
+
+    assert_eq!(
+        engine.eval::<String>(
+            r#"
+                fn eval(x) { x }    // reflect the script back
+
+                eval("40 + 2")
+    "#
+        )?,
+        "40 + 2"
+    );
+
+    Ok(())
+}

tests/var_scope.rs

@@ -42,10 +42,7 @@ fn test_scope_eval() -> Result<(), EvalAltResult> {
     assert_eq!(
         scope
             .get_value::<INT>("y")
-            .ok_or(EvalAltResult::ErrorRuntime(
-                "variable y not found".into(),
-                Default::default()
-            ))?,
+            .expect("variable y should exist"),
         1
     );