Basic Javascript Testing #MoreThanCoding #HackReactor

Hi! I'm Mohammed Zaghloul,

In this tutorial I will show you how to do basic Javascript testing.

In the past, I used to manually test my web applications on the browser, but as my projects grow bigger this process become a big time consuming. I also used to add console.log statements all over the code to see if it's working as expected, unfortunately by doing that I may end up forgetting one of these statements in my code.

Recently, I started implementing basic tests to validate expected output against actual output.

Usually, I follow one of the following options to do that based on allowed time frame.

• Option 1: Is to add a simple console.log statement, that print true or false to the console after evaluating passed boolean expression.

  • We can enhance this option by using console.assert statement that takes a boolean expression as a first parameter, and an error message as a second parameter, and it print's the error message to the console if the assert boolean expression evaluated to false.

• Option 2: Is to implement a simple assert function based on expected output type, and use it to assert that expected and actual outputs are matched.

  • We can enhance this option by wrapping our assertion code in a separate function for each individual test, which will be more organized.

• Option 3: Is to use a testing framework like Mocha and an assertion function like Chai