Implement `TryFromJs` for `JsObject` wrappers (#2809)

This change allows using built-in `JsObject` wrappers with the `TryFromJs` logic, which makes it easier to derive it in complex objects containing known built-ins, being able to use all the power of the wrappers even inside complex structures.

It changes the following:

 * Implements `TryFromJs` for all `JsObject` wrappers ~, except for `JsProxy` and `Js<Int>Array` wrappers~ -> This has now been added.
 *  Adds checker functions for individual typed array objects.
 * Adds some missing checker functions from `Object` to `JsObject`

~The reason for not implementing it for `JsProxy` is that we don't have a way (as far as I can tell) to know if a `JsObject` is a `Proxy` object. The reason for the typed arrays (note that `JsTypedArray` implements `TryFromJs`) is that I didn't find an easy way to know which type of typed array a `JsObject` was. Do we have a way of using a `JsObject` to create a Rust `JsUint8Array` or the like?~

boa_engine/src/object/builtins/jsarray.rs

@@ -3,7 +3,7 @@ use crate::{
     builtins::Array,
     error::JsNativeError,
     object::{JsFunction, JsObject, JsObjectType},
-    value::IntoOrUndefined,
+    value::{IntoOrUndefined, TryFromJs},
     Context, JsResult, JsString, JsValue,
 };
 use boa_gc::{Finalize, Trace};
@@ -40,7 +40,7 @@ impl JsArray {
     /// This does not clone the fields of the array, it only does a shallow clone of the object.
     #[inline]
     pub fn from_object(object: JsObject) -> JsResult<Self> {
-        if object.borrow().is_array() {
+        if object.is_array() {
             Ok(Self { inner: object })
         } else {
             Err(JsNativeError::typ()
@@ -399,3 +399,14 @@ impl Deref for JsArray {
 }
 
 impl JsObjectType for JsArray {}
+
+impl TryFromJs for JsArray {
+    fn try_from_js(value: &JsValue, _context: &mut Context<'_>) -> JsResult<Self> {
+        match value {
+            JsValue::Object(o) => Self::from_object(o.clone()),
+            _ => Err(JsNativeError::typ()
+                .with_message("value is not an Array object")
+                .into()),
+        }
+    }
+}

boa_engine/src/object/builtins/jsarraybuffer.rs

@@ -6,6 +6,7 @@ use crate::{
     object::{
         internal_methods::get_prototype_from_constructor, JsObject, JsObjectType, ObjectData,
     },
+    value::TryFromJs,
     Context, JsResult, JsValue,
 };
 use boa_gc::{Finalize, Trace};
@@ -117,7 +118,7 @@ impl JsArrayBuffer {
     /// This does not clone the fields of the array buffer, it only does a shallow clone of the object.
     #[inline]
     pub fn from_object(object: JsObject) -> JsResult<Self> {
-        if object.borrow().is_array_buffer() {
+        if object.is_array_buffer() {
             Ok(Self { inner: object })
         } else {
             Err(JsNativeError::typ()
@@ -222,3 +223,14 @@ impl Deref for JsArrayBuffer {
 }
 
 impl JsObjectType for JsArrayBuffer {}
+
+impl TryFromJs for JsArrayBuffer {
+    fn try_from_js(value: &JsValue, _context: &mut Context<'_>) -> JsResult<Self> {
+        match value {
+            JsValue::Object(o) => Self::from_object(o.clone()),
+            _ => Err(JsNativeError::typ()
+                .with_message("value is not an ArrayBuffer object")
+                .into()),
+        }
+    }
+}

boa_engine/src/object/builtins/jsdataview.rs

@@ -6,6 +6,7 @@ use crate::{
         internal_methods::get_prototype_from_constructor, JsArrayBuffer, JsObject, JsObjectType,
         ObjectData,
     },
+    value::TryFromJs,
     Context, JsNativeError, JsResult, JsValue,
 };
 
@@ -111,7 +112,7 @@ impl JsDataView {
     /// Create a new `JsDataView` object from an existing object.
     #[inline]
     pub fn from_object(object: JsObject) -> JsResult<Self> {
-        if object.borrow().is_data_view() {
+        if object.is_data_view() {
             Ok(Self { inner: object })
         } else {
             Err(JsNativeError::typ()
@@ -485,3 +486,14 @@ impl Deref for JsDataView {
 }
 
 impl JsObjectType for JsDataView {}
+
+impl TryFromJs for JsDataView {
+    fn try_from_js(value: &JsValue, _context: &mut Context<'_>) -> JsResult<Self> {
+        match value {
+            JsValue::Object(o) => Self::from_object(o.clone()),
+            _ => Err(JsNativeError::typ()
+                .with_message("value is not an DataView object")
+                .into()),
+        }
+    }
+}

boa_engine/src/object/builtins/jsdate.rs

@@ -7,6 +7,7 @@ use chrono::DateTime;
 use crate::{
     builtins::Date,
     object::{JsObject, JsObjectType, ObjectData},
+    value::TryFromJs,
     Context, JsNativeError, JsResult, JsValue,
 };
 
@@ -47,6 +48,18 @@ impl JsDate {
         Self { inner }
     }
 
+    /// Create a new `JsDate` object from an existing object.
+    #[inline]
+    pub fn from_object(object: JsObject) -> JsResult<Self> {
+        if object.is_date() {
+            Ok(Self { inner: object })
+        } else {
+            Err(JsNativeError::typ()
+                .with_message("object is not a Date")
+                .into())
+        }
+    }
+
     /// Return a `Number` representing the milliseconds elapsed since the UNIX epoch.
     ///
     /// Same as JavaScript's `Date.now()`
@@ -587,3 +600,14 @@ impl Deref for JsDate {
 }
 
 impl JsObjectType for JsDate {}
+
+impl TryFromJs for JsDate {
+    fn try_from_js(value: &JsValue, _context: &mut Context<'_>) -> JsResult<Self> {
+        match value {
+            JsValue::Object(o) => Self::from_object(o.clone()),
+            _ => Err(JsNativeError::typ()
+                .with_message("value is not a Date object")
+                .into()),
+        }
+    }
+}

boa_engine/src/object/builtins/jsfunction.rs

@@ -1,7 +1,8 @@
 //! A Rust API wrapper for Boa's `Function` Builtin ECMAScript Object
 use crate::{
     object::{JsObject, JsObjectType},
-    JsValue,
+    value::TryFromJs,
+    Context, JsNativeError, JsResult, JsValue,
 };
 use boa_gc::{Finalize, Trace};
 use std::ops::Deref;
@@ -52,3 +53,18 @@ impl Deref for JsFunction {
 }
 
 impl JsObjectType for JsFunction {}
+
+impl TryFromJs for JsFunction {
+    fn try_from_js(value: &JsValue, _context: &mut Context<'_>) -> JsResult<Self> {
+        match value {
+            JsValue::Object(o) => Self::from_object(o.clone()).ok_or_else(|| {
+                JsNativeError::typ()
+                    .with_message("object is not a function")
+                    .into()
+            }),
+            _ => Err(JsNativeError::typ()
+                .with_message("value is not a Function object")
+                .into()),
+        }
+    }
+}

boa_engine/src/object/builtins/jsgenerator.rs

@@ -2,6 +2,7 @@
 use crate::{
     builtins::generator::{Generator, GeneratorState},
     object::{JsObject, JsObjectType, ObjectData},
+    value::TryFromJs,
     Context, JsNativeError, JsResult, JsValue,
 };
 
@@ -34,7 +35,7 @@ impl JsGenerator {
     /// Create a `JsGenerator` from a regular expression `JsObject`
     #[inline]
     pub fn from_object(object: JsObject) -> JsResult<Self> {
-        if object.borrow().is_generator() {
+        if object.is_generator() {
             Ok(Self { inner: object })
         } else {
             Err(JsNativeError::typ()
@@ -99,3 +100,14 @@ impl Deref for JsGenerator {
 }
 
 impl JsObjectType for JsGenerator {}
+
+impl TryFromJs for JsGenerator {
+    fn try_from_js(value: &JsValue, _context: &mut Context<'_>) -> JsResult<Self> {
+        match value {
+            JsValue::Object(o) => Self::from_object(o.clone()),
+            _ => Err(JsNativeError::typ()
+                .with_message("value is not a Generator object")
+                .into()),
+        }
+    }
+}

boa_engine/src/object/builtins/jsmap.rs

@@ -5,6 +5,7 @@ use crate::{
     error::JsNativeError,
     object::{JsFunction, JsMapIterator, JsObject, JsObjectType, ObjectData},
     string::utf16,
+    value::TryFromJs,
     Context, JsResult, JsValue,
 };
 
@@ -169,7 +170,7 @@ impl JsMap {
     /// ```
     #[inline]
     pub fn from_object(object: JsObject) -> JsResult<Self> {
-        if object.borrow().is_map() {
+        if object.is_map() {
             Ok(Self { inner: object })
         } else {
             Err(JsNativeError::typ()
@@ -422,3 +423,14 @@ impl Deref for JsMap {
 }
 
 impl JsObjectType for JsMap {}
+
+impl TryFromJs for JsMap {
+    fn try_from_js(value: &JsValue, _context: &mut Context<'_>) -> JsResult<Self> {
+        match value {
+            JsValue::Object(o) => Self::from_object(o.clone()),
+            _ => Err(JsNativeError::typ()
+                .with_message("value is not a Map object")
+                .into()),
+        }
+    }
+}

boa_engine/src/object/builtins/jsmap_iterator.rs

@@ -3,6 +3,7 @@ use crate::{
     builtins::map::MapIterator,
     error::JsNativeError,
     object::{JsObject, JsObjectType},
+    value::TryFromJs,
     Context, JsResult, JsValue,
 };
 
@@ -19,7 +20,7 @@ impl JsMapIterator {
     /// Create a [`JsMapIterator`] from a [`JsObject`]. If object is not a `MapIterator`, throw `TypeError`
     #[inline]
     pub fn from_object(object: JsObject) -> JsResult<Self> {
-        if object.borrow().is_map_iterator() {
+        if object.is_map_iterator() {
             Ok(Self { inner: object })
         } else {
             Err(JsNativeError::typ()
@@ -58,3 +59,14 @@ impl Deref for JsMapIterator {
 }
 
 impl JsObjectType for JsMapIterator {}
+
+impl TryFromJs for JsMapIterator {
+    fn try_from_js(value: &JsValue, _context: &mut Context<'_>) -> JsResult<Self> {
+        match value {
+            JsValue::Object(o) => Self::from_object(o.clone()),
+            _ => Err(JsNativeError::typ()
+                .with_message("value is not a MapIterator object")
+                .into()),
+        }
+    }
+}

boa_engine/src/object/builtins/jspromise.rs

@@ -11,6 +11,7 @@ use crate::{
     },
     context::intrinsics::StandardConstructors,
     object::{JsObject, JsObjectType, ObjectData},
+    value::TryFromJs,
     Context, JsError, JsNativeError, JsResult, JsValue,
 };
 
@@ -243,13 +244,13 @@ impl JsPromise {
     /// # }
     /// ```
     #[inline]
-    pub fn from_object(object: JsObject) -> JsResult<JsPromise> {
+    pub fn from_object(object: JsObject) -> JsResult<Self> {
         if !object.is_promise() {
             return Err(JsNativeError::typ()
                 .with_message("`object` is not a Promise")
                 .into());
         }
-        Ok(JsPromise { inner: object })
+        Ok(Self { inner: object })
     }
 
     /// Resolves a `JsValue` into a `JsPromise`.
@@ -883,3 +884,14 @@ impl std::ops::Deref for JsPromise {
 }
 
 impl JsObjectType for JsPromise {}
+
+impl TryFromJs for JsPromise {
+    fn try_from_js(value: &JsValue, _context: &mut Context<'_>) -> JsResult<Self> {
+        match value {
+            JsValue::Object(o) => Self::from_object(o.clone()),
+            _ => Err(JsNativeError::typ()
+                .with_message("value is not a Promise object")
+                .into()),
+        }
+    }
+}

boa_engine/src/object/builtins/jsproxy.rs

@@ -6,7 +6,8 @@ use crate::{
     native_function::{NativeFunction, NativeFunctionPointer},
     object::{FunctionObjectBuilder, JsObject, JsObjectType, ObjectData},
     string::utf16,
-    Context, JsResult, JsValue,
+    value::TryFromJs,
+    Context, JsNativeError, JsResult, JsValue,
 };
 
 use super::JsFunction;
@@ -33,6 +34,19 @@ impl JsProxy {
     pub fn builder(target: JsObject) -> JsProxyBuilder {
         JsProxyBuilder::new(target)
     }
+
+    /// Create a [`JsProxy`] from a [`JsObject`], if the object is not a `Proxy` throw a
+    /// `TypeError`.
+    #[inline]
+    pub fn from_object(object: JsObject) -> JsResult<Self> {
+        if object.borrow().is_proxy() {
+            Ok(Self { inner: object })
+        } else {
+            Err(JsNativeError::typ()
+                .with_message("object is not a Proxy")
+                .into())
+        }
+    }
 }
 
 impl From<JsProxy> for JsObject {
@@ -60,6 +74,17 @@ impl std::ops::Deref for JsProxy {
 
 impl JsObjectType for JsProxy {}
 
+impl TryFromJs for JsProxy {
+    fn try_from_js(value: &JsValue, _context: &mut Context<'_>) -> JsResult<Self> {
+        match value {
+            JsValue::Object(o) => Self::from_object(o.clone()),
+            _ => Err(JsNativeError::typ()
+                .with_message("value is not a Proxy object")
+                .into()),
+        }
+    }
+}
+
 /// `JsRevocableProxy` provides a wrapper for `JsProxy` that can be disabled.
 ///
 /// Safe interface for the [`Proxy.revocable`][revocable] method that creates a

boa_engine/src/object/builtins/jsregexp.rs

@@ -2,6 +2,7 @@
 use crate::{
     builtins::RegExp,
     object::{JsArray, JsObject, JsObjectType},
+    value::TryFromJs,
     Context, JsNativeError, JsResult, JsValue,
 };
 
@@ -79,7 +80,7 @@ impl JsRegExp {
     /// Create a `JsRegExp` from a regular expression `JsObject`
     #[inline]
     pub fn from_object(object: JsObject) -> JsResult<Self> {
-        if object.borrow().is_regexp() {
+        if object.is_regexp() {
             Ok(Self { inner: object })
         } else {
             Err(JsNativeError::typ()
@@ -279,3 +280,14 @@ impl Deref for JsRegExp {
 }
 
 impl JsObjectType for JsRegExp {}
+
+impl TryFromJs for JsRegExp {
+    fn try_from_js(value: &JsValue, _context: &mut Context<'_>) -> JsResult<Self> {
+        match value {
+            JsValue::Object(o) => Self::from_object(o.clone()),
+            _ => Err(JsNativeError::typ()
+                .with_message("value is not a RegExp object")
+                .into()),
+        }
+    }
+}

boa_engine/src/object/builtins/jsset.rs

@@ -7,6 +7,7 @@ use crate::{
     builtins::Set,
     error::JsNativeError,
     object::{JsFunction, JsObject, JsObjectType, JsSetIterator},
+    value::TryFromJs,
     Context, JsResult, JsValue,
 };
 
@@ -143,7 +144,7 @@ impl JsSet {
     /// Utility: Creates `JsSet` from `JsObject`, if not a Set throw `TypeError`.
     #[inline]
     pub fn from_object(object: JsObject) -> JsResult<Self> {
-        if object.borrow().is_set() {
+        if object.is_set() {
             Ok(Self { inner: object })
         } else {
             Err(JsNativeError::typ()
@@ -185,3 +186,14 @@ impl Deref for JsSet {
 }
 
 impl JsObjectType for JsSet {}
+
+impl TryFromJs for JsSet {
+    fn try_from_js(value: &JsValue, _context: &mut Context<'_>) -> JsResult<Self> {
+        match value {
+            JsValue::Object(o) => Self::from_object(o.clone()),
+            _ => Err(JsNativeError::typ()
+                .with_message("value is not a Set object")
+                .into()),
+        }
+    }
+}

boa_engine/src/object/builtins/jsset_iterator.rs

@@ -7,6 +7,7 @@ use crate::{
     builtins::set::SetIterator,
     error::JsNativeError,
     object::{JsObject, JsObjectType},
+    value::TryFromJs,
     Context, JsResult, JsValue,
 };
 
@@ -20,7 +21,7 @@ impl JsSetIterator {
     /// Create a `JsSetIterator` from a `JsObject`.
     /// If object is not a `SetIterator`, throw `TypeError`.
     pub fn from_object(object: JsObject) -> JsResult<Self> {
-        if object.borrow().is_set_iterator() {
+        if object.is_set_iterator() {
             Ok(Self { inner: object })
         } else {
             Err(JsNativeError::typ()
@@ -58,3 +59,14 @@ impl Deref for JsSetIterator {
 }
 
 impl JsObjectType for JsSetIterator {}
+
+impl TryFromJs for JsSetIterator {
+    fn try_from_js(value: &JsValue, _context: &mut Context<'_>) -> JsResult<Self> {
+        match value {
+            JsValue::Object(o) => Self::from_object(o.clone()),
+            _ => Err(JsNativeError::typ()
+                .with_message("value is not a SetIterator object")
+                .into()),
+        }
+    }
+}

boa_engine/src/object/builtins/jstypedarray.rs

@@ -4,25 +4,28 @@ use crate::{
     builtins::BuiltInConstructor,
     error::JsNativeError,
     object::{JsArrayBuffer, JsFunction, JsObject, JsObjectType},
-    value::IntoOrUndefined,
+    value::{IntoOrUndefined, TryFromJs},
     Context, JsResult, JsString, JsValue,
 };
 use boa_gc::{Finalize, Trace};
 use std::ops::Deref;
 
-/// `JsTypedArray` provides a wrapper for Boa's implementation of the ECMAScript `TypedArray` builtin object.
+/// `JsTypedArray` provides a wrapper for Boa's implementation of the ECMAScript `TypedArray`
+/// builtin object.
 #[derive(Debug, Clone, Trace, Finalize)]
 pub struct JsTypedArray {
     inner: JsValue,
 }
 
 impl JsTypedArray {
-    /// Create a [`JsTypedArray`] from a [`JsObject`], if the object is not a typed array throw a `TypeError`.
+    /// Create a [`JsTypedArray`] from a [`JsObject`], if the object is not a typed array throw a
+    /// `TypeError`.
     ///
-    /// This does not clone the fields of the typed array, it only does a shallow clone of the object.
+    /// This does not clone the fields of the typed array, it only does a shallow clone of the
+    /// object.
     #[inline]
     pub fn from_object(object: JsObject) -> JsResult<Self> {
-        if object.borrow().is_typed_array() {
+        if object.is_typed_array() {
             Ok(Self {
                 inner: object.into(),
             })
@@ -346,15 +349,55 @@ impl Deref for JsTypedArray {
 
 impl JsObjectType for JsTypedArray {}
 
+impl TryFromJs for JsTypedArray {
+    fn try_from_js(value: &JsValue, _context: &mut Context<'_>) -> JsResult<Self> {
+        match value {
+            JsValue::Object(o) => Self::from_object(o.clone()),
+            _ => Err(JsNativeError::typ()
+                .with_message("value is not a TypedArray object")
+                .into()),
+        }
+    }
+}
+
 macro_rules! JsTypedArrayType {
-    ($name:ident, $constructor_function:ident, $constructor_object:ident, $element:ty) => {
-        #[doc = concat!("`", stringify!($name), "` provides a wrapper for Boa's implementation of the ECMAScript `", stringify!($constructor_function) ,"` builtin object.")]
+    (
+        $name:ident,
+        $constructor_function:ident,
+        $checker_function:ident,
+        $constructor_object:ident,
+        $element:ty
+    ) => {
+
+        #[doc = concat!(
+            "`", stringify!($name),
+            "` provides a wrapper for Boa's implementation of the ECMAScript `",
+            stringify!($constructor_function) ,"` builtin object."
+        )]
         #[derive(Debug, Clone, Trace, Finalize)]
         pub struct $name {
             inner: JsTypedArray,
         }
 
         impl $name {
+            #[doc = concat!("Creates a `", stringify!($name),
+                "` using a [`JsObject`]. It will make sure that the object is of the correct kind."
+            )]
+            #[inline]
+            pub fn from_object(object: JsObject) -> JsResult<Self> {
+                if object.$checker_function() {
+                    Ok(Self {
+                        inner: JsTypedArray {
+                            inner: object.into(),
+                        },
+                    })
+                } else {
+                    Err(JsNativeError::typ()
+                        .with_message("object is not a TypedArray")
+                        .into())
+                }
+            }
+
             /// Create the typed array from a [`JsArrayBuffer`].
             pub fn from_array_buffer(
                 array_buffer: JsArrayBuffer,
@@ -441,14 +484,77 @@ macro_rules! JsTypedArrayType {
                 &self.inner
             }
         }
+
+        impl TryFromJs for $name {
+            fn try_from_js(value: &JsValue, _context: &mut Context<'_>) -> JsResult<Self> {
+                match value {
+                    JsValue::Object(o) => Self::from_object(o.clone()),
+                    _ => Err(JsNativeError::typ()
+                        .with_message(concat!(
+                            "value is not a ",
+                            stringify!($constructor_function),
+                            " object"
+                        ))
+                        .into()),
+                }
+            }
+        }
     };
 }
 
-JsTypedArrayType!(JsUint8Array, Uint8Array, typed_uint8_array, u8);
-JsTypedArrayType!(JsInt8Array, Int8Array, typed_int8_array, i8);
-JsTypedArrayType!(JsUint16Array, Uint16Array, typed_uint16_array, u16);
-JsTypedArrayType!(JsInt16Array, Int16Array, typed_int16_array, i16);
-JsTypedArrayType!(JsUint32Array, Uint32Array, typed_uint32_array, u32);
-JsTypedArrayType!(JsInt32Array, Int32Array, typed_int32_array, i32);
-JsTypedArrayType!(JsFloat32Array, Float32Array, typed_float32_array, f32);
-JsTypedArrayType!(JsFloat64Array, Float64Array, typed_float64_array, f64);
+JsTypedArrayType!(
+    JsUint8Array,
+    Uint8Array,
+    is_typed_uint8_array,
+    typed_uint8_array,
+    u8
+);
+JsTypedArrayType!(
+    JsInt8Array,
+    Int8Array,
+    is_typed_int8_array,
+    typed_int8_array,
+    i8
+);
+JsTypedArrayType!(
+    JsUint16Array,
+    Uint16Array,
+    is_typed_uint16_array,
+    typed_uint16_array,
+    u16
+);
+JsTypedArrayType!(
+    JsInt16Array,
+    Int16Array,
+    is_typed_int16_array,
+    typed_int16_array,
+    i16
+);
+JsTypedArrayType!(
+    JsUint32Array,
+    Uint32Array,
+    is_typed_uint32_array,
+    typed_uint32_array,
+    u32
+);
+JsTypedArrayType!(
+    JsInt32Array,
+    Int32Array,
+    is_typed_int32_array,
+    typed_int32_array,
+    i32
+);
+JsTypedArrayType!(
+    JsFloat32Array,
+    Float32Array,
+    is_typed_float32_array,
+    typed_float32_array,
+    f32
+);
+JsTypedArrayType!(
+    JsFloat64Array,
+    Float64Array,
+    is_typed_float64_array,
+    typed_float64_array,
+    f64
+);

boa_engine/src/object/jsobject.rs

@@ -309,6 +309,17 @@ impl JsObject {
         self.borrow().is_array()
     }
 
+    /// Checks if it's a `DataView` object.
+    ///
+    /// # Panics
+    ///
+    /// Panics if the object is currently mutably borrowed.
+    #[inline]
+    #[track_caller]
+    pub fn is_data_view(&self) -> bool {
+        self.borrow().is_data_view()
+    }
+
     /// Checks if it is an `ArrayIterator` object.
     ///
     /// # Panics
@@ -463,6 +474,17 @@ impl JsObject {
         self.borrow().is_bigint()
     }
 
+    /// Checks if it's a `Date` object.
+    ///
+    /// # Panics
+    ///
+    /// Panics if the object is currently mutably borrowed.
+    #[inline]
+    #[track_caller]
+    pub fn is_date(&self) -> bool {
+        self.borrow().is_date()
+    }
+
     /// Checks if it's a `RegExp` object.
     ///
     /// # Panics
@@ -485,6 +507,94 @@ impl JsObject {
         self.borrow().is_typed_array()
     }
 
+    /// Checks if it's a `Uint8Array` object.
+    ///
+    /// # Panics
+    ///
+    /// Panics if the object is currently mutably borrowed.
+    #[inline]
+    #[track_caller]
+    pub fn is_typed_uint8_array(&self) -> bool {
+        self.borrow().is_typed_uint8_array()
+    }
+
+    /// Checks if it's a `Int8Array` object.
+    ///
+    /// # Panics
+    ///
+    /// Panics if the object is currently mutably borrowed.
+    #[inline]
+    #[track_caller]
+    pub fn is_typed_int8_array(&self) -> bool {
+        self.borrow().is_typed_int8_array()
+    }
+
+    /// Checks if it's a `Uint16Array` object.
+    ///
+    /// # Panics
+    ///
+    /// Panics if the object is currently mutably borrowed.
+    #[inline]
+    #[track_caller]
+    pub fn is_typed_uint16_array(&self) -> bool {
+        self.borrow().is_typed_uint16_array()
+    }
+
+    /// Checks if it's a `Int16Array` object.
+    ///
+    /// # Panics
+    ///
+    /// Panics if the object is currently mutably borrowed.
+    #[inline]
+    #[track_caller]
+    pub fn is_typed_int16_array(&self) -> bool {
+        self.borrow().is_typed_int16_array()
+    }
+
+    /// Checks if it's a `Uint32Array` object.
+    ///
+    /// # Panics
+    ///
+    /// Panics if the object is currently mutably borrowed.
+    #[inline]
+    #[track_caller]
+    pub fn is_typed_uint32_array(&self) -> bool {
+        self.borrow().is_typed_uint32_array()
+    }
+
+    /// Checks if it's a `Int32Array` object.
+    ///
+    /// # Panics
+    ///
+    /// Panics if the object is currently mutably borrowed.
+    #[inline]
+    #[track_caller]
+    pub fn is_typed_int32_array(&self) -> bool {
+        self.borrow().is_typed_int32_array()
+    }
+
+    /// Checks if it's a `Float32Array` object.
+    ///
+    /// # Panics
+    ///
+    /// Panics if the object is currently mutably borrowed.
+    #[inline]
+    #[track_caller]
+    pub fn is_typed_float32_array(&self) -> bool {
+        self.borrow().is_typed_float32_array()
+    }
+
+    /// Checks if it's a `Float64Array` object.
+    ///
+    /// # Panics
+    ///
+    /// Panics if the object is currently mutably borrowed.
+    #[inline]
+    #[track_caller]
+    pub fn is_typed_float64_array(&self) -> bool {
+        self.borrow().is_typed_float64_array()
+    }
+
     /// Checks if it's a `Promise` object.
     ///
     /// # Panics
@@ -507,6 +617,17 @@ impl JsObject {
         self.borrow().is_ordinary()
     }
 
+    /// Checks if it's a proxy object.
+    ///
+    /// # Panics
+    ///
+    /// Panics if the object is currently mutably borrowed.
+    #[inline]
+    #[track_caller]
+    pub fn is_proxy(&self) -> bool {
+        self.borrow().is_proxy()
+    }
+
     /// Returns `true` if it holds an Rust type that implements `NativeObject`.
     ///
     /// # Panics

boa_engine/src/object/mod.rs

@@ -45,7 +45,7 @@ use crate::{
         set::ordered_set::OrderedSet,
         set::SetIterator,
         string::StringIterator,
-        typed_array::integer_indexed_object::IntegerIndexed,
+        typed_array::{integer_indexed_object::IntegerIndexed, TypedArrayKind},
         DataView, Date, Promise, RegExp,
     },
     js_string,
@@ -1429,6 +1429,118 @@ impl Object {
         )
     }
 
+    /// Checks if it a `Uint8Array` object.
+    #[inline]
+    pub const fn is_typed_uint8_array(&self) -> bool {
+        if let ObjectData {
+            kind: ObjectKind::IntegerIndexed(ref int),
+            ..
+        } = self.data
+        {
+            matches!(int.typed_array_name(), TypedArrayKind::Uint8)
+        } else {
+            false
+        }
+    }
+
+    /// Checks if it a `Int8Array` object.
+    #[inline]
+    pub const fn is_typed_int8_array(&self) -> bool {
+        if let ObjectData {
+            kind: ObjectKind::IntegerIndexed(ref int),
+            ..
+        } = self.data
+        {
+            matches!(int.typed_array_name(), TypedArrayKind::Int8)
+        } else {
+            false
+        }
+    }
+
+    /// Checks if it a `Uint16Array` object.
+    #[inline]
+    pub const fn is_typed_uint16_array(&self) -> bool {
+        if let ObjectData {
+            kind: ObjectKind::IntegerIndexed(ref int),
+            ..
+        } = self.data
+        {
+            matches!(int.typed_array_name(), TypedArrayKind::Uint16)
+        } else {
+            false
+        }
+    }
+
+    /// Checks if it a `Int16Array` object.
+    #[inline]
+    pub const fn is_typed_int16_array(&self) -> bool {
+        if let ObjectData {
+            kind: ObjectKind::IntegerIndexed(ref int),
+            ..
+        } = self.data
+        {
+            matches!(int.typed_array_name(), TypedArrayKind::Int16)
+        } else {
+            false
+        }
+    }
+
+    /// Checks if it a `Uint32Array` object.
+    #[inline]
+    pub const fn is_typed_uint32_array(&self) -> bool {
+        if let ObjectData {
+            kind: ObjectKind::IntegerIndexed(ref int),
+            ..
+        } = self.data
+        {
+            matches!(int.typed_array_name(), TypedArrayKind::Uint32)
+        } else {
+            false
+        }
+    }
+
+    /// Checks if it a `Int32Array` object.
+    #[inline]
+    pub const fn is_typed_int32_array(&self) -> bool {
+        if let ObjectData {
+            kind: ObjectKind::IntegerIndexed(ref int),
+            ..
+        } = self.data
+        {
+            matches!(int.typed_array_name(), TypedArrayKind::Int32)
+        } else {
+            false
+        }
+    }
+
+    /// Checks if it a `Float32Array` object.
+    #[inline]
+    pub const fn is_typed_float32_array(&self) -> bool {
+        if let ObjectData {
+            kind: ObjectKind::IntegerIndexed(ref int),
+            ..
+        } = self.data
+        {
+            matches!(int.typed_array_name(), TypedArrayKind::Float32)
+        } else {
+            false
+        }
+    }
+
+    /// Checks if it a `Float64Array` object.
+    #[inline]
+    pub const fn is_typed_float64_array(&self) -> bool {
+        if let ObjectData {
+            kind: ObjectKind::IntegerIndexed(ref int),
+            ..
+        } = self.data
+        {
+            matches!(int.typed_array_name(), TypedArrayKind::Float64)
+        } else {
+            false
+        }
+    }
+
     /// Gets the data view data if the object is a `DataView`.
     #[inline]
     pub const fn as_data_view(&self) -> Option<&DataView> {

boa_engine/src/object/operations.rs

@@ -300,13 +300,16 @@ impl JsObject {
         Ok(desc.is_some())
     }
 
-    /// Call this object.
+    /// `Call ( F, V [ , argumentsList ] )`
     ///
     /// # Panics
     ///
     /// Panics if the object is currently mutably borrowed.
-    // <https://tc39.es/ecma262/#sec-prepareforordinarycall>
-    // <https://tc39.es/ecma262/#sec-ecmascript-function-objects-call-thisargument-argumentslist>
+    ///
+    /// More information:
+    ///  - [ECMAScript reference][spec]
+    ///
+    /// [spec]: https://tc39.es/ecma262/#sec-call
     #[track_caller]
     #[inline]
     pub fn call(
@@ -317,8 +320,9 @@ impl JsObject {
     ) -> JsResult<JsValue> {
         // 1. If argumentsList is not present, set argumentsList to a new empty List.
         // 2. If IsCallable(F) is false, throw a TypeError exception.
-        let function = JsFunction::from_object(self.clone())
-            .ok_or_else(|| JsNativeError::typ().with_message("not a function"))?;
+        let function = JsFunction::from_object(self.clone()).ok_or_else(|| {
+            JsNativeError::typ().with_message("only callable objects / functions can be called")
+        })?;
 
         // 3. Return ? F.[[Call]](V, argumentsList).
         function.__call__(this, args, context)