fix: replace panics with proper error handling in module env and dyna…

core/engine/src/builtins/function/arguments.rs

@@ -137,7 +137,9 @@ impl MappedArguments {
     /// [spec]: https://tc39.es/ecma262/#sec-makeargsetter
     pub(crate) fn set(&self, index: u32, value: &JsValue) {
         if let Some(binding_index) = self.binding_indices.get(index as usize).copied().flatten() {
-            self.environment.set(binding_index, value.clone());
+            // Mapped arguments always point to function-scope direct bindings,
+            // which cannot fail.
+            drop(self.environment.set(binding_index, value.clone()));
         }
     }
 }

core/engine/src/builtins/function/mod.rs

@@ -1066,7 +1066,7 @@ pub(crate) fn function_call(
             BindingLocatorScope::Stack(index),
             0,
             function_object.clone().into(),
-        );
+        )?;
         last_env += 1;
     }
 
@@ -1167,7 +1167,7 @@ fn function_construct(
             BindingLocatorScope::Stack(index),
             0,
             this_function_object.clone().into(),
-        );
+        )?;
         last_env += 1;
     }
 

core/engine/src/environments/runtime/declarative/function.rs

@@ -49,8 +49,9 @@ impl FunctionEnvironment {
     ///
     /// Panics if the binding value is out of range.
     #[track_caller]
-    pub(crate) fn set(&self, index: u32, value: JsValue) {
+    pub(crate) fn set(&self, index: u32, value: JsValue) -> JsResult<()> {
         self.bindings.borrow_mut()[index as usize] = Some(value);
+        Ok(())
     }
 
     /// Gets the bindings of this poisonable environment.

core/engine/src/environments/runtime/declarative/global.rs

@@ -1,4 +1,4 @@
-use crate::JsValue;
+use crate::{JsResult, JsValue};
 use boa_gc::{Finalize, GcRefCell, Trace};
 
 #[derive(Debug, Trace, Finalize)]
@@ -30,8 +30,9 @@ impl GlobalEnvironment {
     ///
     /// Panics if the binding value is out of range.
     #[track_caller]
-    pub(crate) fn set(&self, index: u32, value: JsValue) {
+    pub(crate) fn set(&self, index: u32, value: JsValue) -> JsResult<()> {
         self.bindings.borrow_mut()[index as usize] = Some(value);
+        Ok(())
     }
 
     /// Gets the bindings of this poisonable environment.

core/engine/src/environments/runtime/declarative/lexical.rs

@@ -1,6 +1,6 @@
 use boa_gc::{Finalize, GcRefCell, Trace};
 
-use crate::JsValue;
+use crate::{JsResult, JsValue};
 
 #[derive(Debug, Trace, Finalize)]
 pub(crate) struct LexicalEnvironment {
@@ -31,8 +31,9 @@ impl LexicalEnvironment {
     ///
     /// Panics if the binding value is out of range.
     #[track_caller]
-    pub(crate) fn set(&self, index: u32, value: JsValue) {
+    pub(crate) fn set(&self, index: u32, value: JsValue) -> JsResult<()> {
         self.bindings.borrow_mut()[index as usize] = Some(value);
+        Ok(())
     }
 
     /// Gets the bindings of this poisonable environment.

core/engine/src/environments/runtime/declarative/mod.rs

@@ -82,12 +82,16 @@ impl DeclarativeEnvironment {
 
     /// Sets the binding value from the environment by index.
     ///
+    /// # Errors
+    ///
+    /// Returns an error if the binding is an indirect module reference.
+    ///
     /// # Panics
     ///
     /// Panics if the binding value is out of range.
     #[track_caller]
-    pub(crate) fn set(&self, index: u32, value: JsValue) {
-        self.kind.set(index, value);
+    pub(crate) fn set(&self, index: u32, value: JsValue) -> JsResult<()> {
+        self.kind.set(index, value)
     }
 
     /// `GetThisBinding`
@@ -199,11 +203,15 @@ impl DeclarativeEnvironmentKind {
 
     /// Sets the binding value from the environment by index.
     ///
+    /// # Errors
+    ///
+    /// Returns an error if the binding is an indirect module reference.
+    ///
     /// # Panics
     ///
     /// Panics if the binding value is out of range.
     #[track_caller]
-    pub(crate) fn set(&self, index: u32, value: JsValue) {
+    pub(crate) fn set(&self, index: u32, value: JsValue) -> JsResult<()> {
         match self {
             Self::Lexical(inner) => inner.set(index, value),
             Self::Global(inner) => inner.set(index, value),

core/engine/src/environments/runtime/declarative/module.rs

@@ -3,7 +3,7 @@ use std::cell::RefCell;
 use boa_ast::scope::Scope;
 use boa_gc::{Finalize, GcRefCell, Trace};
 
-use crate::{JsString, JsValue, module::Module};
+use crate::{JsResult, JsString, JsValue, error::PanicError, module::Module};
 
 /// Type of accessor used to access an indirect binding.
 #[derive(Debug, Clone)]
@@ -95,18 +95,22 @@ impl ModuleEnvironment {
 
     /// Sets the binding value from the environment by index.
     ///
-    /// # Panics
+    /// # Errors
     ///
-    /// Panics if the binding value is out of range.
+    /// Returns a `TypeError` if the binding is an indirect reference to another environment.
     #[track_caller]
-    pub(crate) fn set(&self, index: u32, value: JsValue) {
+    pub(crate) fn set(&self, index: u32, value: JsValue) -> JsResult<()> {
         let mut bindings = self.bindings.borrow_mut();
 
         match &mut bindings[index as usize] {
-            BindingType::Direct(v) => *v = Some(value),
-            BindingType::Indirect(_) => {
-                panic!("cannot modify indirect references to other environments")
+            BindingType::Direct(v) => {
+                *v = Some(value);
+                Ok(())
             }
+            BindingType::Indirect(_) => Err(PanicError::new(
+                "cannot modify indirect references to other environments",
+            )
+            .into()),
         }
     }
 

core/engine/src/environments/runtime/mod.rs

@@ -267,6 +267,10 @@ impl EnvironmentStack {
 
     /// Set the value of a lexical binding.
     ///
+    /// # Errors
+    ///
+    /// Returns an error if the binding is an indirect module reference.
+    ///
     /// # Panics
     ///
     /// Panics if the environment or binding index are out of range.
@@ -276,7 +280,7 @@ impl EnvironmentStack {
         environment: BindingLocatorScope,
         binding_index: u32,
         value: JsValue,
-    ) {
+    ) -> JsResult<()> {
         let env = match environment {
             BindingLocatorScope::GlobalObject | BindingLocatorScope::GlobalDeclarative => {
                 self.global()
@@ -287,11 +291,15 @@ impl EnvironmentStack {
                 .and_then(Environment::as_declarative)
                 .expect("must be declarative environment"),
         };
-        env.set(binding_index, value);
+        env.set(binding_index, value)
     }
 
     /// Set the value of a binding if it is uninitialized.
     ///
+    /// # Errors
+    ///
+    /// Returns an error if the binding is an indirect module reference.
+    ///
     /// # Panics
     ///
     /// Panics if the environment or binding index are out of range.
@@ -301,7 +309,7 @@ impl EnvironmentStack {
         environment: BindingLocatorScope,
         binding_index: u32,
         value: JsValue,
-    ) {
+    ) -> JsResult<()> {
         let env = match environment {
             BindingLocatorScope::GlobalObject | BindingLocatorScope::GlobalDeclarative => {
                 self.global()
@@ -313,8 +321,9 @@ impl EnvironmentStack {
                 .expect("must be declarative environment"),
         };
         if env.get(binding_index).is_none() {
-            env.set(binding_index, value);
+            env.set(binding_index, value)?;
         }
+        Ok(())
     }
 
     /// Push a private environment to the private environment stack.
@@ -559,11 +568,11 @@ impl Context {
             }
             BindingLocatorScope::GlobalDeclarative => {
                 let env = self.vm.frame().environments.global();
-                env.set(locator.binding_index(), value);
+                env.set(locator.binding_index(), value)?;
             }
             BindingLocatorScope::Stack(index) => match self.environment_expect(index) {
                 Environment::Declarative(decl) => {
-                    decl.set(locator.binding_index(), value);
+                    decl.set(locator.binding_index(), value)?;
                 }
                 Environment::Object(obj) => {
                     let key = locator.name().clone();

core/engine/src/module/source.rs

@@ -1790,7 +1790,7 @@ impl SourceTextModule {
                         locator.scope(),
                         locator.binding_index(),
                         namespace.into(),
-                    );
+                    )?;
                 }
                 ImportBinding::Single {
                     locator,
@@ -1816,7 +1816,7 @@ impl SourceTextModule {
                             locator.scope(),
                             locator.binding_index(),
                             namespace.into(),
-                        );
+                        )?;
                     }
                 },
             }
@@ -1832,7 +1832,7 @@ impl SourceTextModule {
                 locator.scope(),
                 locator.binding_index(),
                 function.into(),
-            );
+            )?;
         }
 
         // 25. Remove moduleContext from the execution context stack.

core/engine/src/module/synthetic.rs

@@ -217,7 +217,7 @@ impl SyntheticModule {
                     export_name.to_std_string_escaped()
                 ))
             })?;
-        env.set(locator.binding_index(), export_value);
+        env.set(locator.binding_index(), export_value)?;
 
         Ok(())
     }
@@ -346,7 +346,8 @@ impl SyntheticModule {
                 locator.scope(),
                 locator.binding_index(),
                 JsValue::undefined(),
-            );
+            )
+            .expect("synthetic module bindings are always direct");
         }
 
         let env = envs

core/engine/src/vm/opcode/call/mod.rs

@@ -378,7 +378,9 @@ async fn load_dyn_import(
     match referrer {
         Referrer::Module(mod_ref) => {
             let ModuleKind::SourceText(src) = mod_ref.kind() else {
-                panic!("referrer cannot be a synthetic module");
+                return Err(JsNativeError::typ()
+                    .with_message("referrer cannot be a synthetic module")
+                    .into());
             };
 
             let mut loaded_modules = src.loaded_modules().borrow_mut();

core/engine/src/vm/opcode/define/mod.rs

@@ -16,7 +16,7 @@ pub(crate) struct DefVar;
 
 impl DefVar {
     #[inline(always)]
-    pub(super) fn operation(index: IndexOperand, context: &mut Context) {
+    pub(super) fn operation(index: IndexOperand, context: &mut Context) -> JsResult<()> {
         // TODO: spec specifies to return `empty` on empty vars, but we're trying to initialize.
         let binding_locator = context.vm.frame().code_block.bindings[usize::from(index)].clone();
 
@@ -28,7 +28,7 @@ impl DefVar {
                 binding_locator.scope(),
                 binding_locator.binding_index(),
                 JsValue::undefined(),
-            );
+            )
     }
 }
 
@@ -80,14 +80,14 @@ impl PutLexicalValue {
     pub(super) fn operation(
         (value, index): (RegisterOperand, IndexOperand),
         context: &mut Context,
-    ) {
+    ) -> JsResult<()> {
         let value = context.vm.get_register(value.into()).clone();
         let binding_locator = context.vm.frame().code_block.bindings[usize::from(index)].clone();
         context.vm.frame_mut().environments.put_lexical_value(
             binding_locator.scope(),
             binding_locator.binding_index(),
             value,
-        );
+        )
     }
 }