XFESystem

namespace XFESystem.Browser.Tests;

public sealed class DomPrototypeMutationTests
{
    [Fact]
    public void ElementPrototypeInterceptorsObserveActualMutationAndTheBorrowedReceiver()
    {
        var page = new BrowserService();
        try
        {
            page.Navigate("about:Start");
            string result = page.ExecuteJavaScript("""
                const first=document.createElement('div'),second=document.createElement('div'),child=document.createElement('span');
                document.body.append(first,second);let observed=0;
                const original=Element.prototype.appendChild;
                Element.prototype.appendChild=function(node){observed++;return original.call(this,node)};
                first.appendChild(child);Node.prototype.appendChild.call(second,child);
                [observed,child.parentNode===second,Object.hasOwn(first,'appendChild'),typeof original].join(',')
                """);
            Assert.Equal("1,true,false,function", result);
        }
        finally { page.Release(); }
    }
    [Fact]
    public void BorrowedInsertionReplacementAndRemovalUseTheActualParentAndReturnTheOriginalNode()
    {
        var page = new BrowserService();
        try
        {
            page.Navigate("about:Start");
            Assert.Equal("true,true,true,true", page.ExecuteJavaScript("""
                const parent=document.createElement('div'),a=document.createElement('i'),b=document.createElement('b'),c=document.createElement('u');
                parent.append(a);const inserted=Node.prototype.insertBefore.call(parent,b,a);
                const replaced=Node.prototype.replaceChild.call(parent,c,a);
                const removed=Node.prototype.removeChild.call(parent,b);
                [inserted===b,replaced===a,removed===b,parent.firstChild===c].join(',')
                """));
            Assert.Equal("true", page.ExecuteJavaScript("let rejected=false;try{Node.prototype.appendChild.call({},c)}catch{rejected=true}rejected"));
        }
        finally { page.Release(); }
    }
}