ladybird/Userland/Libraries/LibWeb/HTML/UniversalGlobalScope.cpp

/*
 * Copyright (c) 2022, Andrew Kaster <akaster@serenityos.org>
 * Copyright (c) 2023, Linus Groh <linusg@serenityos.org>
 * Copyright (c) 2023, Luke Wilde <lukew@serenityos.org>
 * Copyright (c) 2024, Shannon Booth <shannon@serenityos.org>
 *
 * SPDX-License-Identifier: BSD-2-Clause
 */

#include <AK/Base64.h>
#include <AK/String.h>
#include <AK/Utf8View.h>
#include <AK/Vector.h>
#include <LibJS/Heap/HeapFunction.h>
#include <LibWeb/HTML/Scripting/ExceptionReporter.h>
#include <LibWeb/HTML/StructuredSerialize.h>
#include <LibWeb/HTML/StructuredSerializeOptions.h>
#include <LibWeb/HTML/UniversalGlobalScope.h>
#include <LibWeb/HTML/Window.h>
#include <LibWeb/Infra/Strings.h>
#include <LibWeb/WebIDL/AbstractOperations.h>
#include <LibWeb/WebIDL/DOMException.h>
#include <LibWeb/WebIDL/ExceptionOr.h>
#include <LibWeb/WebIDL/Types.h>

namespace Web::HTML {

UniversalGlobalScopeMixin::~UniversalGlobalScopeMixin() = default;

// https://html.spec.whatwg.org/multipage/webappapis.html#dom-btoa
WebIDL::ExceptionOr<String> UniversalGlobalScopeMixin::btoa(String const& data) const
{
    auto& vm = this_impl().vm();
    auto& realm = *vm.current_realm();

    // The btoa(data) method must throw an "InvalidCharacterError" DOMException if data contains any character whose code point is greater than U+00FF.
    Vector<u8> byte_string;
    byte_string.ensure_capacity(data.bytes().size());
    for (u32 code_point : Utf8View(data)) {
        if (code_point > 0xff)
            return WebIDL::InvalidCharacterError::create(realm, "Data contains characters outside the range U+0000 and U+00FF"_string);
        byte_string.append(code_point);
    }

    // Otherwise, the user agent must convert data to a byte sequence whose nth byte is the eight-bit representation of the nth code point of data,
    // and then must apply forgiving-base64 encode to that byte sequence and return the result.
    return TRY_OR_THROW_OOM(vm, encode_base64(byte_string.span()));
}

// https://html.spec.whatwg.org/multipage/webappapis.html#dom-atob
WebIDL::ExceptionOr<String> UniversalGlobalScopeMixin::atob(String const& data) const
{
    auto& vm = this_impl().vm();
    auto& realm = *vm.current_realm();

    // 1. Let decodedData be the result of running forgiving-base64 decode on data.
    auto decoded_data = decode_base64(data);

    // 2. If decodedData is failure, then throw an "InvalidCharacterError" DOMException.
    if (decoded_data.is_error())
        return WebIDL::InvalidCharacterError::create(realm, "Input string is not valid base64 data"_string);

    // 3. Return decodedData.
    // decode_base64() returns a byte buffer. LibJS uses UTF-8 for strings. Use isomorphic decoding to convert bytes to UTF-8.
    return Infra::isomorphic_decode(decoded_data.value());
}

// https://html.spec.whatwg.org/multipage/timers-and-user-prompts.html#dom-queuemicrotask
void UniversalGlobalScopeMixin::queue_microtask(WebIDL::CallbackType& callback)
{
    auto& vm = this_impl().vm();
    auto& realm = *vm.current_realm();

    JS::GCPtr<DOM::Document> document;
    if (is<Window>(this_impl()))
        document = &static_cast<Window&>(this_impl()).associated_document();

    // The queueMicrotask(callback) method must queue a microtask to invoke callback, and if callback throws an exception, report the exception.
    HTML::queue_a_microtask(document, JS::create_heap_function(realm.heap(), [&callback, &realm] {
        auto result = WebIDL::invoke_callback(callback, {});
        if (result.is_error())
            HTML::report_exception(result, realm);
    }));
}

// https://html.spec.whatwg.org/multipage/structured-data.html#dom-structuredclone
WebIDL::ExceptionOr<JS::Value> UniversalGlobalScopeMixin::structured_clone(JS::Value value, StructuredSerializeOptions const& options) const
{
    auto& vm = this_impl().vm();
    (void)options;

    // 1. Let serialized be ? StructuredSerializeWithTransfer(value, options["transfer"]).
    // FIXME: Use WithTransfer variant of the AO
    auto serialized = TRY(structured_serialize(vm, value));

    // 2. Let deserializeRecord be ? StructuredDeserializeWithTransfer(serialized, this's relevant realm).
    // FIXME: Use WithTransfer variant of the AO
    auto deserialized = TRY(structured_deserialize(vm, serialized, relevant_realm(this_impl()), {}));

    // 3. Return deserializeRecord.[[Deserialized]].
    return deserialized;
}

}