Fix some suggestions

boa/src/environment/lexical_environment.rs

@@ -93,6 +93,11 @@ impl Context {
             .recursive_get_this_binding(self)
     }
 
+    pub(crate) fn get_global_this_binding(&mut self) -> JsResult<JsValue> {
+        let global = self.realm.global_env.clone();
+        global.get_this_binding(self)
+    }
+
     pub(crate) fn create_mutable_binding(
         &mut self,
         name: &str,

boa/src/vm/code_block.rs

@@ -16,14 +16,11 @@ use crate::{
     object::{internal_methods::get_prototype_from_constructor, JsObject, ObjectData},
     property::PropertyDescriptor,
     syntax::ast::node::FormalParameter,
-    vm::Opcode,
+    vm::{call_frame::FinallyReturn, CallFrame, Opcode},
     Context, JsResult, JsString, JsValue,
 };
 use gc::Gc;
-
-use std::{cmp::Ordering, convert::TryInto, fmt::Write, mem::size_of};
-
-use super::{call_frame::FinallyReturn, CallFrame};
+use std::{convert::TryInto, fmt::Write, mem::size_of};
 
 /// This represents whether a value can be read from [`CodeBlock`] code.
 pub unsafe trait Readable {}
@@ -566,13 +563,12 @@ impl JsObject {
                 let arg_count = args.len();
 
                 // Push function arguments to the stack.
-                let args = match code.params.len().cmp(&args.len()) {
-                    Ordering::Greater => {
-                        let mut v = args.to_vec();
-                        v.extend(vec![JsValue::Undefined; code.params.len() - args.len()]);
-                        v
-                    }
-                    Ordering::Less | Ordering::Equal => args.to_vec(),
+                let args = if code.params.len() > args.len() {
+                    let mut v = args.to_vec();
+                    v.extend(vec![JsValue::Undefined; code.params.len() - args.len()]);
+                    v
+                } else {
+                    args.to_vec()
                 };
 
                 for arg in args.iter().rev() {
@@ -581,10 +577,20 @@ impl JsObject {
 
                 let param_count = code.params.len();
 
+                let this = if this.is_null_or_undefined() {
+                    context
+                        .get_global_this_binding()
+                        .expect("global env must have this binding")
+                } else {
+                    this.to_object(context)
+                        .expect("conversion to object cannot fail here")
+                        .into()
+                };
+
                 context.vm.push_frame(CallFrame {
                     prev: None,
                     code,
-                    this: this.clone(),
+                    this,
                     pc: 0,
                     catch: Vec::new(),
                     finally_return: FinallyReturn::None,
@@ -728,13 +734,12 @@ impl JsObject {
                 let arg_count = args.len();
 
                 // Push function arguments to the stack.
-                let args = match code.params.len().cmp(&args.len()) {
-                    Ordering::Greater => {
-                        let mut v = args.to_vec();
-                        v.extend(vec![JsValue::Undefined; code.params.len() - args.len()]);
-                        v
-                    }
-                    Ordering::Less | Ordering::Equal => args.to_vec(),
+                let args = if code.params.len() > args.len() {
+                    let mut v = args.to_vec();
+                    v.extend(vec![JsValue::Undefined; code.params.len() - args.len()]);
+                    v
+                } else {
+                    args.to_vec()
                 };
 
                 for arg in args.iter().rev() {
@@ -743,6 +748,16 @@ impl JsObject {
 
                 let param_count = code.params.len();
 
+                let this = if this.is_null_or_undefined() {
+                    context
+                        .get_global_this_binding()
+                        .expect("global env must have this binding")
+                } else {
+                    this.to_object(context)
+                        .expect("conversion to object cannot fail here")
+                        .into()
+                };
+
                 context.vm.push_frame(CallFrame {
                     prev: None,
                     code,

boa/src/vm/mod.rs

@@ -909,7 +909,10 @@ impl Context {
                 let this = &self.vm.frame().this;
 
                 let new_env = FunctionEnvironmentRecord::new(
-                    this.clone().as_object().unwrap().clone(), //TODO: is this ok? this_function object on stack mb?
+                    this.clone()
+                        .as_object()
+                        .expect("this must always be an object")
+                        .clone(),
                     if is_constructor || !is_lexical {
                         Some(this.clone())
                     } else {

boa_tester/src/exec/js262.rs

@@ -86,17 +86,17 @@ fn detach_array_buffer(
 ///
 /// Accepts a string value as its first argument and executes it as an ECMAScript script.
 fn eval_script(_this: &JsValue, args: &[JsValue], context: &mut Context) -> JsResult<JsValue> {
-    // eprintln!("called $262.evalScript()");
-
     if let Some(source_text) = args.get(0).and_then(|val| val.as_string()) {
-        #[cfg(not(feature = "vm"))]
         match boa::parse(source_text.as_str(), false) {
             // TODO: check strict
             Err(e) => context.throw_type_error(format!("Uncaught Syntax Error: {}", e)),
+            #[cfg(not(feature = "vm"))]
             Ok(statement_list) => statement_list.run(context),
+            // Calling eval here parses the code a second time.
+            // TODO: We can fix this after we have have defined the public api for the vm executer.
+            #[cfg(feature = "vm")]
+            Ok(_) => context.eval(source_text.as_str()),
         }
-        #[cfg(feature = "vm")]
-        context.eval(source_text.as_str())
     } else {
         Ok(JsValue::undefined())
     }