测试在哪个函数中执行回调

Question

I'm trying to test in which function this callback function in executed. It should return a boolean value. I hope you know what I mean.

Here the code example:

function test(par, callback) {
  // ...
  if (typeof callback == 'function') { // make sure the callback is a function
    callback.call(this);
  }

}

test("par", function() {
  console.log("Test if in function test: " + "<if this is in function test>");
});

Is this similar to instanceof ?

Answer 1

There's a non-standard way of doing it since the removal of arguments.caller

 function test(par, callback) { // ... if (typeof callback == 'function') { // make sure the callback is a function callback.call(this); } } test("par", function cb() { var isTestCaller = cb.caller === test; console.log("Test if in function test: " + isTestCaller); }); 

Another possible way doing it through error stacks (still non-standard):

 var checkCaller = function(fnName) { var e = new Error(); var caller = e.stack.split('\\n')[2].trim().split(' ')[1]; return caller === fnName; } function wrapper(){ console.log(checkCaller('wrapper')); } wrapper();