Run code through the Chrome debugger with an optional args parameter

runWithDebugger.js

(function() {
  'use strict';

  function runWithDebugger(f, args) {
    if (typeof f !== 'function') { throw 'f must be a function' }
    // The apply() method treats unspecified args or null or undefined args as 'no args'.
    if (args === undefined || typeof args === 'object' && (args === null || Array.isArray(args))) {
      debugger;
      f.apply(null, args);
    } else {
      throw 'args must be an array, null or undefined';
    }
  }

  window.runWithDebugger = runWithDebugger;
})();

If args is not specified it is treated as undefined, which tells the apply method that there are no arguments. (See Function.prototype.apply() for details.)

Test cases

function sayHi() {
  console.log('hi!');
}

runWithDebugger(sayHi); // 'hi!'

function sayHiTo(name) {
  console.log('hi ' + name);
}

runWithDebugger(sayHiTo, ['foobaz']); // 'hi foobaz'

function sayFullName(first, last) {
  console.log(first + ' '  + last);
}

runWithDebugger(sayFullName, ['foobaz', 'quux']); // 'foobaz quux'

Additional test cases

runWithDebugger(sayHi, null); // 'hi'
runWithDebugger(sayHi, undefined); // 'hi'
runWithDebugger(sayHi, []); // 'hi'
runWithDebugger(sayHi, {}); // 'Uncaught args must be an array, null or undefined'
runWithDebugger('sayHi', []); // 'Uncaught f must be a function