Get Current Function Name In Strict Mode

I need the current function name as a string to log to our log facility. But arguments.callee.name only works in loose mode. How to get the function name under 'use strict'?

Solution 1:

For logging/debugging purposes, you can create a new Error object in the logger and inspect its .stack property, e.g.

functionlogIt(message) {
    var stack = newError().stack,
        caller = stack.split('\n')[2].trim();
    console.log(caller + ":" + message);
}

functiona(b) {
    b()
}

a(functionxyz() {
    logIt('hello');
});

Solution 2:

You can bind function as its context then you can access its name via this.nameproperty:

function x(){
  console.log(this.name);
}
x.bind(x)();

Solution 3:

After little research here is a good solution :

functiongetFnName(fn) {
  var f = typeof fn == 'function';
  var s = f && ((fn.name && ['', fn.name]) || fn.toString().match(/function ([^\(]+)/));
  return (!f && 'not a function') || (s && s[1] || 'anonymous');
}



functiontest(){
    console.log(getFnName(this));
}

test  = test.bind(test);

test(); // 'test'

Source : https://gist.github.com/dfkaye/6384439

Solution 4:

Building on @georg solution, this one returns just the function name. Note though that it may fail if called from an anonymous function

functiongetFncName() {
    const stackLine = (newError())!.stack!.split('\n')[2].trim()
    const fncName = stackLine.match(/at Object.([^ ]+)/)?.[1]
    return fncName
}

functionFoo() {
    console.log(getFncName()) // prints 'Foo'
}

Solution 5:

A simple solution to dynamically retrieve function names [like magic variables] is the use of scoped variables, and the Function.name property.

{
  function foo() {
    alert (a.name);
  }; let a = foo
}
{
  function foo2() {
    alert(a.name)
  }; let a = foo2
};
foo();//logs foo
foo2();//logs foo2

Note: Nested functions cease to be source elements, and are hence not hoisted. Also, this technique cannot work with anonymous functions.