line-reverse-engineer-proxy-tomography.js

const [chrome,navigator,window,document,$vars] = (()=>{
    let vars = [];
    let proxyMethodNames =
    `apply
    construct
    defineProperty
    deleteProperty
    get
    getOwnPropertyDescriptor
    getPrototypeOf
    has
    isExtensible
    ownKeys
    preventExtensions
    set
    setPrototypeOf`
    .split("\n").map(v=>v.trim());
    
    let makeTarget = function(obj){
        let fn = function(){};
        for(let key in obj){
            fn[key] = obj[key];
        }
        return fn;
    }
    

    let defaultHandler = {};
    for(let name of proxyMethodNames){
        defaultHandler[name] = (target)=>{
            console.log(`[proxy] ${name} on ${target.path}`);
        };
    }

    let handler = Object.create(defaultHandler);
    
    handler.get = function(target,key){
        if(typeof key === 'symbol'){
            key = key.toString();
        }
        let path = `${target.path}.${key}`;
        if(path === "document.getElementsByTagName($2[1]).length"){
            return 2;
        }
        return new Proxy(makeTarget({path}),handler);
    };
    handler.set = function(target,key,value){
        let n = vars.length;
        vars.push(value);
        console.log(`[proxy] ${target.path}.${key} = $${n}`);
    };
    handler.construct = function(target,args){
        let path;
        if(args.length === 0){
            path = `new ${target.path}()`;
        }else{
            let n = vars.length;
            vars.push(args);
            path = `new ${target.path}($${n}[${args.length}])`;
        }
        console.log(`[proxy] ${path}`);
        return new Proxy(makeTarget({path:`(${path})`}),handler);
    };
    handler.apply = function(target,that,args){
        console.log(args);
        let path;
        if(args.length === 0){
            path = `${target.path}()`;
        }else{
            let n = vars.length;
            vars.push(args);
            path = `${target.path}($${n}[${args.length}])`;
        }
        console.log(`[proxy] ${path}`);
        return new Proxy(makeTarget({path:`${path}`}),handler);
    }
    
    
    return [
        new Proxy(makeTarget({path:"chrome"}),handler),
        new Proxy(makeTarget({path:"navigator"}),handler),
        new Proxy(makeTarget({path:"window"}),handler),
        new Proxy(makeTarget({path:"document"}),handler),
        vars];
})();

//a = chrome.a;
//chrome.a = 2;
//let b = new chrome.a.b.c(2,3,4);
//b(2)