Add basic support for executeAsyncScript.

This relies on a global webdriverCallback function, which is visible to content.
Obviously that's not a long term solution for a number of reasons, but it allows
us to experiment for now

components/script/dom/webidls/Window.webidl

@@ -56,6 +56,9 @@
 
   //void postMessage(any message, DOMString targetOrigin, optional sequence<Transferable> transfer);
 
+  // Shouldn't be public, but just to make things work for now
+  void webdriverCallback(optional any result);
+
   // also has obsolete members
 };
 Window implements GlobalEventHandlers;

components/script/dom/window.rs

@@ -35,8 +35,10 @@ use script_task::{TimerSource, ScriptChan, ScriptPort, NonWorkerScriptChan};
 use script_task::ScriptMsg;
 use script_traits::ScriptControlChan;
 use timers::{IsInterval, TimerId, TimerManager, TimerCallback};
+use webdriver_handlers::jsval_to_webdriver;
 
 use devtools_traits::{DevtoolsControlChan, TimelineMarker, TimelineMarkerType, TracingMetadata};
+use webdriver_traits::EvaluateJSReply;
 use msg::compositor_msg::ScriptListener;
 use msg::constellation_msg::{LoadData, PipelineId, SubpageId, ConstellationChan, WindowSizeData, WorkerId};
 use net_traits::ResourceTask;
@@ -166,6 +168,9 @@ pub struct Window {
 
     /// A counter of the number of pending reflows for this window.
     pending_reflow_count: Cell<u32>,
+
+    /// A channel for communicating results of async scripts back to the webdriver server
+    webdriver_script_chan: RefCell<Option<Sender<Result<EvaluateJSReply, ()>>>>
 }
 
 impl Window {
@@ -483,6 +488,17 @@ impl<'a> WindowMethods for JSRef<'a, Window> {
         let doc = self.Document().root();
         doc.r().cancel_animation_frame(ident);
     }
+
+    fn WebdriverCallback(self, cx: *mut JSContext, val: JSVal) {
+        let rv = jsval_to_webdriver(cx, val);
+        {
+            let opt_chan = self.webdriver_script_chan.borrow();
+            if let Some(ref chan) = *opt_chan {
+                chan.send(rv).unwrap();
+            }
+        }
+        self.set_webdriver_script_chan(None);
+    }
 }
 
 pub trait WindowHelpers {
@@ -523,6 +539,7 @@ pub trait WindowHelpers {
     fn emit_timeline_marker(self, marker: TimelineMarker);
     fn set_devtools_timeline_marker(self, marker: TimelineMarkerType, reply: Sender<TimelineMarker>);
     fn drop_devtools_timeline_markers(self);
+    fn set_webdriver_script_chan(self, chan: Option<Sender<Result<EvaluateJSReply, ()>>>);
 }
 
 pub trait ScriptHelpers {
@@ -880,6 +897,10 @@ impl<'a> WindowHelpers for JSRef<'a, Window> {
         self.devtools_markers.borrow_mut().clear();
         *self.devtools_marker_sender.borrow_mut() = None;
     }
+
+    fn set_webdriver_script_chan(self, chan: Option<Sender<Result<EvaluateJSReply, ()>>>) {
+        *self.webdriver_script_chan.borrow_mut() = chan;
+    }
 }
 
 impl Window {
@@ -947,6 +968,7 @@ impl Window {
             devtools_marker_sender: RefCell::new(None),
             devtools_markers: RefCell::new(HashSet::new()),
             devtools_wants_updates: Cell::new(false),
+            webdriver_script_chan: RefCell::new(None),
         };
 
         WindowBinding::Wrap(runtime.cx(), win)

components/script/script_task.rs

@@ -316,7 +316,7 @@ pub struct ScriptTask {
     /// The JavaScript runtime.
     js_runtime: Rc<Runtime>,
 
-    mouse_over_targets: DOMRefCell<Vec<JS<Node>>>
+    mouse_over_targets: DOMRefCell<Vec<JS<Node>>>,
 }
 
 /// In the event of task failure, all data on the stack runs its destructor. However, there
@@ -814,7 +814,9 @@ impl ScriptTask {
             WebDriverScriptCommand::GetElementText(node_id, reply) =>
                 webdriver_handlers::handle_get_text(&page, pipeline_id, node_id, reply),
             WebDriverScriptCommand::GetTitle(reply) =>
-                webdriver_handlers::handle_get_title(&page, pipeline_id, reply)
+                webdriver_handlers::handle_get_title(&page, pipeline_id, reply),
+            WebDriverScriptCommand::ExecuteAsyncScript(script, reply) =>
+                webdriver_handlers::handle_execute_async_script(&page, pipeline_id, script, reply),
         }
     }
 

components/script/webdriver_handlers.rs

@@ -12,8 +12,10 @@ use dom::bindings::codegen::Bindings::NodeBinding::NodeMethods;
 use dom::bindings::codegen::Bindings::NodeListBinding::NodeListMethods;
 use dom::bindings::js::{OptionalRootable, Rootable, Temporary};
 use dom::node::{Node, NodeHelpers};
-use dom::window::ScriptHelpers;
+use dom::window::{ScriptHelpers, WindowHelpers};
 use dom::document::DocumentHelpers;
+use js::jsapi::JSContext;
+use js::jsval::JSVal;
 use page::Page;
 use msg::constellation_msg::PipelineId;
 use script_task::get_page;
@@ -35,26 +37,38 @@ fn find_node_by_unique_id(page: &Rc<Page>, pipeline: PipelineId, node_id: String
     None
 }
 
+pub fn jsval_to_webdriver(cx: *mut JSContext, val: JSVal) -> Result<EvaluateJSReply, ()> {
+    if val.is_undefined() {
+        Ok(EvaluateJSReply::VoidValue)
+    } else if val.is_boolean() {
+        Ok(EvaluateJSReply::BooleanValue(val.to_boolean()))
+    } else if val.is_double() {
+        Ok(EvaluateJSReply::NumberValue(FromJSValConvertible::from_jsval(cx, val, ()).unwrap()))
+    } else if val.is_string() {
+        //FIXME: use jsstring_to_str when jsval grows to_jsstring
+        Ok(EvaluateJSReply::StringValue(FromJSValConvertible::from_jsval(cx, val, StringificationBehavior::Default).unwrap()))
+    } else if val.is_null() {
+        Ok(EvaluateJSReply::NullValue)
+    } else {
+        Err(())
+    }
+}
+
 pub fn handle_execute_script(page: &Rc<Page>, pipeline: PipelineId, eval: String, reply: Sender<Result<EvaluateJSReply, ()>>) {
     let page = get_page(&*page, pipeline);
     let window = page.window().root();
     let cx = window.r().get_cx();
     let rval = window.r().evaluate_js_on_global_with_result(&eval);
 
-    reply.send(if rval.is_undefined() {
-        Ok(EvaluateJSReply::VoidValue)
-    } else if rval.is_boolean() {
-        Ok(EvaluateJSReply::BooleanValue(rval.to_boolean()))
-    } else if rval.is_double() {
-        Ok(EvaluateJSReply::NumberValue(FromJSValConvertible::from_jsval(cx, rval, ()).unwrap()))
-    } else if rval.is_string() {
-        //FIXME: use jsstring_to_str when jsval grows to_jsstring
-        Ok(EvaluateJSReply::StringValue(FromJSValConvertible::from_jsval(cx, rval, StringificationBehavior::Default).unwrap()))
-    } else if rval.is_null() {
-        Ok(EvaluateJSReply::NullValue)
-    } else {
-        Err(())
-    }).unwrap();
+    reply.send(jsval_to_webdriver(cx, rval)).unwrap();
+}
+
+
+pub fn handle_execute_async_script(page: &Rc<Page>, pipeline: PipelineId, eval: String, reply: Sender<Result<EvaluateJSReply, ()>>) {
+    let page = get_page(&*page, pipeline);
+    let window = page.window().root();
+    window.r().set_webdriver_script_chan(Some(reply));
+    window.r().evaluate_js_on_global_with_result(&eval);
 }
 
 pub fn handle_find_element_css(page: &Rc<Page>, _pipeline: PipelineId, selector: String, reply: Sender<Result<Option<String>, ()>>) {