freeCodeCamp Challenge Guide: Test if a Variable or Function is Defined

Test if a Variable or Function is Defined


Problem Explanation

To begin, locate the file “tests/1_unit_tests.js”.

This file contains multiple suites of tests for the project, and this challenge requires you to make the tests in /** 2 */ pass.


Hints

Hint 1

The lines in the test should be changed from assert.fail() to either assert.isDefined() or assert.isUndefined().


Solutions

Solution #1(Click to Show/Hide)
/** 2 - Use assert.isDefined() or assert.isUndefined() to make the tests pass. **/
test('#isDefined, #isUndefined', function() {
  assert.isDefined(null, 'null is not undefined');
  assert.isUndefined(undefined, 'undefined IS undefined');
  assert.isDefined('hello', 'a string is not undefined');
});