is_instance_of_error.rs•2.39 kB
// The below method was taken from `deno_core`
// https://github.com/denoland/deno_core/blob/main/LICENSE.md - MIT License
// Copyright 2018-2024 the Deno authors
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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// SOFTWARE.
use deno_core::v8;
/// Implements the JS check `value instanceof Error`. Similar to
/// `Value::is_native_error()` but more closely matches the semantics
/// of `instanceof`. `Value::is_native_error()` also checks for static class
/// inheritance rather than just scanning the prototype chain, which doesn't
/// work with our WebIDL implementation of `DOMException`.
pub fn is_instance_of_error(scope: &mut v8::HandleScope<'_>, value: v8::Local<v8::Value>) -> bool {
if !value.is_object() {
return false;
}
let message = v8::String::empty(scope);
let error_prototype = v8::Exception::error(scope, message)
.to_object(scope)
.unwrap()
.get_prototype(scope)
.unwrap();
let mut maybe_prototype = value.to_object(scope).unwrap().get_prototype(scope);
while let Some(prototype) = maybe_prototype {
if !prototype.is_object() {
return false;
}
if prototype.strict_equals(error_prototype) {
return true;
}
maybe_prototype = prototype
.to_object(scope)
.and_then(|o| o.get_prototype(scope));
}
false
}