freeCodeCamp/guide/english/certifications/information-security-and-quality-assurance/quality-assurance-and-testing-with-chai/learn-how-javascript-assertions-work/index.md

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Learn How JavaScript Assertions Work

Learn How JavaScript Assertions Work

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Problem Explanation

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

This file contains multiple suites of tests for the project, and this first challenge requires you to make the tests in /** 1 */ to pass.

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Hints

Hint 1

The two lines in the test should be changed from assert.fail() to either assert.isNull() or assert.isNotNull().

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Solutions

Solution 1 (Click to Show/Hide)

/** 1 - Use assert.isNull() or assert.isNotNull() to make the tests pass. **/
test('#isNull, #isNotNull', function() {
  assert.isNull(
    null,
    'this is an optional error description - e.g. null is null'
  );
  assert.isNotNull(1, '1 is not null');
});