script: Return a Result from GlobalScope::evaluate_script_on_global_with_result (#38549)

Make GlobalScope::evaluate_script_on_global_with_result return a Result
instead of a boolean. This is the first step to resolve issue #37810.

Testing: Should not break or fix any existing tests

---------

Signed-off-by: Rodion Borovyk <rodion.borovyk@gmail.com>

components/script/devtools.rs

@@ -60,7 +60,7 @@ pub(crate) fn handle_evaluate_js(
         let source_code = SourceCode::Text(Rc::new(DOMString::from_string(eval)));
         // TODO: run code with SpiderMonkey Debugger API, like Firefox does
         // <https://searchfox.org/mozilla-central/rev/f6a806c38c459e0e0d797d264ca0e8ad46005105/devtools/server/actors/webconsole/eval-with-debugger.js#270>
-        global.evaluate_script_on_global_with_result(
+        _ = global.evaluate_script_on_global_with_result(
             &source_code,
             "<eval>",
             rval.handle_mut(),

components/script/dom/debuggerglobalscope.rs

@@ -6,6 +6,7 @@ use base::id::PipelineId;
 use constellation_traits::ScriptToConstellationChan;
 use devtools_traits::{ScriptToDevtoolsControlMsg, WorkerId};
 use dom_struct::dom_struct;
+use embedder_traits::JavaScriptEvaluationError;
 use embedder_traits::resources::{self, Resource};
 use ipc_channel::ipc::IpcSender;
 use js::jsval::UndefinedValue;
@@ -104,7 +105,7 @@ impl DebuggerGlobalScope {
         GlobalScope::get_cx()
     }
 
-    fn evaluate_js(&self, script: &str, can_gc: CanGc) -> bool {
+    fn evaluate_js(&self, script: &str, can_gc: CanGc) -> Result<(), JavaScriptEvaluationError> {
         rooted!(in (*Self::get_cx()) let mut rval = UndefinedValue());
         self.global_scope.evaluate_js_on_global_with_result(
             script,
@@ -117,7 +118,10 @@ impl DebuggerGlobalScope {
     }
 
     pub(crate) fn execute(&self, can_gc: CanGc) {
-        if !self.evaluate_js(&resources::read_string(Resource::DebuggerJS), can_gc) {
+        if self
+            .evaluate_js(&resources::read_string(Resource::DebuggerJS), can_gc)
+            .is_err()
+        {
             let ar = enter_realm(self);
             report_pending_exception(Self::get_cx(), true, InRealm::Entered(&ar), can_gc);
         }

components/script/dom/globalscope.rs

@@ -26,7 +26,7 @@ use content_security_policy::CspList;
 use crossbeam_channel::Sender;
 use devtools_traits::{PageError, ScriptToDevtoolsControlMsg};
 use dom_struct::dom_struct;
-use embedder_traits::EmbedderMsg;
+use embedder_traits::{EmbedderMsg, JavaScriptEvaluationError};
 use ipc_channel::ipc::{self, IpcSender};
 use ipc_channel::router::ROUTER;
 use js::glue::{IsWrapper, UnwrapObjectDynamic};
@@ -2762,7 +2762,7 @@ impl GlobalScope {
         script_base_url: ServoUrl,
         can_gc: CanGc,
         introduction_type: Option<&'static CStr>,
-    ) -> bool {
+    ) -> Result<(), JavaScriptEvaluationError> {
         let source_code = SourceCode::Text(Rc::new(DOMString::from_string((*code).to_string())));
         self.evaluate_script_on_global_with_result(
             &source_code,
@@ -2789,7 +2789,7 @@ impl GlobalScope {
         script_base_url: ServoUrl,
         can_gc: CanGc,
         introduction_type: Option<&'static CStr>,
-    ) -> bool {
+    ) -> Result<(), JavaScriptEvaluationError> {
         let cx = GlobalScope::get_cx();
 
         let ar = enter_realm(self);
@@ -2815,7 +2815,7 @@ impl GlobalScope {
                     if compiled_script.is_null() {
                         debug!("error compiling Dom string");
                         report_pending_exception(cx, true, InRealm::Entered(&ar), can_gc);
-                        return false;
+                        return Err(JavaScriptEvaluationError::CompilationFailure);
                     }
                 },
                 SourceCode::Compiled(pre_compiled_script) => {
@@ -2865,10 +2865,11 @@ impl GlobalScope {
             if !result {
                 debug!("error evaluating Dom string");
                 report_pending_exception(cx, true, InRealm::Entered(&ar), can_gc);
+                return Err(JavaScriptEvaluationError::EvaluationFailure);
             }
 
             maybe_resume_unwind();
-            result
+            Ok(())
         }
     }
 

components/script/dom/htmlscriptelement.rs

@@ -1160,7 +1160,7 @@ impl HTMLScriptElement {
             self.line_number as u32
         };
         rooted!(in(*GlobalScope::get_cx()) let mut rval = UndefinedValue());
-        window
+        _ = window
             .as_global_scope()
             .evaluate_script_on_global_with_result(
                 &script.code,

components/script/dom/userscripts.rs

@@ -31,7 +31,7 @@ pub(crate) fn load_script(head: &HTMLHeadElement) {
                 Rc::new(DOMString::from_string(user_script.script))
             );
             let global_scope = win.as_global_scope();
-            global_scope.evaluate_script_on_global_with_result(
+            _ = global_scope.evaluate_script_on_global_with_result(
                 &script_text,
                 &user_script.source_file.map(|path| path.to_string_lossy().to_string()).unwrap_or_default(),
                 rval.handle_mut(),

components/script/dom/worklet.rs

@@ -691,7 +691,7 @@ impl WorkletThread {
         // to the main script thread.
         // https://github.com/w3c/css-houdini-drafts/issues/407
         let ok = script
-            .map(|script| global_scope.evaluate_js(&script, can_gc))
+            .map(|s| global_scope.evaluate_js(&s, can_gc).is_ok())
             .unwrap_or(false);
 
         if !ok {

components/script/dom/workletglobalscope.rs

@@ -9,6 +9,7 @@ use constellation_traits::{ScriptToConstellationChan, ScriptToConstellationMessa
 use crossbeam_channel::Sender;
 use devtools_traits::ScriptToDevtoolsControlMsg;
 use dom_struct::dom_struct;
+use embedder_traits::JavaScriptEvaluationError;
 use ipc_channel::ipc::IpcSender;
 use js::jsval::UndefinedValue;
 use js::rust::Runtime;
@@ -124,7 +125,11 @@ impl WorkletGlobalScope {
     }
 
     /// Evaluate a JS script in this global.
-    pub(crate) fn evaluate_js(&self, script: &str, can_gc: CanGc) -> bool {
+    pub(crate) fn evaluate_js(
+        &self,
+        script: &str,
+        can_gc: CanGc,
+    ) -> Result<(), JavaScriptEvaluationError> {
         debug!("Evaluating Dom in a worklet.");
         rooted!(in (*GlobalScope::get_cx()) let mut rval = UndefinedValue());
         self.globalscope.evaluate_js_on_global_with_result(

components/script/script_thread.rs

@@ -3738,7 +3738,7 @@ impl ScriptThread {
         // Script source is ready to be evaluated (11.)
         let _ac = enter_realm(global_scope);
         rooted!(in(*GlobalScope::get_cx()) let mut jsval = UndefinedValue());
-        global_scope.evaluate_js_on_global_with_result(
+        _ = global_scope.evaluate_js_on_global_with_result(
             &script_source,
             jsval.handle_mut(),
             ScriptFetchOptions::default_classic_script(global_scope),
@@ -4093,7 +4093,7 @@ impl ScriptThread {
         let context = window.get_cx();
 
         rooted!(in(*context) let mut return_value = UndefinedValue());
-        global_scope.evaluate_js_on_global_with_result(
+        _ = global_scope.evaluate_js_on_global_with_result(
             &script,
             return_value.handle_mut(),
             ScriptFetchOptions::default_classic_script(global_scope),

components/script/timers.rs

@@ -556,7 +556,7 @@ impl JsTimerTask {
                 let cx = GlobalScope::get_cx();
                 rooted!(in(*cx) let mut rval = UndefinedValue());
                 // FIXME(cybai): Use base url properly by saving private reference for timers (#27260)
-                global.evaluate_js_on_global_with_result(
+                _ = global.evaluate_js_on_global_with_result(
                     code_str,
                     rval.handle_mut(),
                     ScriptFetchOptions::default_classic_script(&global),

components/script/webdriver_handlers.rs

@@ -524,17 +524,17 @@ pub(crate) fn handle_execute_script(
 
             rooted!(in(*cx) let mut rval = UndefinedValue());
             let global = window.as_global_scope();
-            let result = if global.evaluate_js_on_global_with_result(
+            let evaluation_result = global.evaluate_js_on_global_with_result(
                 &eval,
                 rval.handle_mut(),
                 ScriptFetchOptions::default_classic_script(global),
                 global.api_base_url(),
                 can_gc,
                 None, // No known `introductionType` for JS code from WebDriver
-            ) {
+            );
-                jsval_to_webdriver(cx, global, rval.handle(), realm, can_gc)
+            let result = match evaluation_result {
-            } else {
+                Ok(_) => jsval_to_webdriver(cx, global, rval.handle(), realm, can_gc),
-                Err(WebDriverJSError::JSError)
+                Err(_) => Err(WebDriverJSError::JSError),
             };
 
             if reply.send(result).is_err() {
@@ -566,14 +566,17 @@ pub(crate) fn handle_execute_async_script(
             rooted!(in(*cx) let mut rval = UndefinedValue());
 
             let global_scope = window.as_global_scope();
-            if !global_scope.evaluate_js_on_global_with_result(
+            if global_scope
+                .evaluate_js_on_global_with_result(
                     &eval,
                     rval.handle_mut(),
                     ScriptFetchOptions::default_classic_script(global_scope),
                     global_scope.api_base_url(),
                     can_gc,
                     None, // No known `introductionType` for JS code from WebDriver
-            ) {
+                )
+                .is_err()
+            {
                 reply_sender.send(Err(WebDriverJSError::JSError)).unwrap();
             }
         },

components/shared/embedder/lib.rs

@@ -1033,6 +1033,10 @@ impl From<&WebDriverJSValue> for JSValue {
 
 #[derive(Clone, Debug, Deserialize, PartialEq, Serialize)]
 pub enum JavaScriptEvaluationError {
+    /// The script could not be compiled
+    CompilationFailure,
+    /// The script could not be evaluated
+    EvaluationFailure,
     /// An internal Servo error prevented the JavaSript evaluation from completing properly.
     /// This indicates a bug in Servo.
     InternalError,