I'm trying to find a way to "extract" all internally defined variables within a function passed to another function. This looks to be impossible, but something tells me that I haven't tried all possible solutions. I need to get a references to the callerFunction's internalVariable inside the tryReadInternalVarvalue
The code is simplified, but the similar code already works with the JavaScript array .findIndex-method - it doesn't care about scopes and the strict mode. In the code sample below, exactly in the tryReadInternalVarValue I need to find which value was used against my targetObj.title to match. I have control over my targetObj.
const tryReadInternalVarValue = function(functionRef) {
const targetObj = {
title: "World"
};
const isMatch = functionRef(targetObj);
if (!isMatch) {
throw Error(``);
}
// Here must go my code to "extract" all the functionRef internal variables
// naive console.log(functionRef[["Scopes"]]["Closure"]["internalVariable"]) ==> "Hello"
// Is there a way (like Reflection) to figure out which value
// was used against the targetObj.title to compare HERE?
// How I would extract the "Hello" value out of the passed function's
// internally declared variable in STRICT MODE?
return isMatch;
}
const callerFunction = function() {
const internalVariable = "Hello";
const meCallingThisFunction = function (passingThisObject) {
return passingThisObject.title === internalVariable;
}
return tryReadInternalVarValue(meCallingThisFunction)
}
console.log(callerFunction());
I tried:
- arguments.caller - in strict mode it's not available
- functionRef.call(new Proxy({}, {get(target, p, receiver) { console.log()}}), targetObj)
