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Unit Test Lessons

Up until now, all the coding lessons in this course have tested your code's console output (what's printed). For example, a lesson might expect your code (in conjunction with the code we provide) to console.log something like:

Price: 0.2
NumMessages: 18

If your code prints that exact output, you pass. If it doesn't, you fail. Haw-haw.

A New Type of Lesson

Going forward, you'll also encounter a new type of lesson: unit tests. If this isn't your first course with us, you'll know what I'm talking about, but in case you haven't, a unit test is just an automated program that tests a small "unit" of code. Usually just a function or two. Your editor will now have multiple tabs: the main.js file containing your code, and the main_test.js file containing our unit tests.

These new unit-test-style lessons will test your code's functionality rather than its output. Our tests will call functions in your code with different arguments, and expect specific return values. If your code returns the correct values, you pass. If it doesn't, you fail.

There are two reasons for this change:

  1. It's more realistic. In the real world, you'll be writing unit tests and running them against your code to make sure it works as expected.
  2. You can run and debug your code with console.log statements, and leave those print statements in when you submit. Unlike the output-based lessons, you won't have to remove your console.log statements to pass.

Assignment

Complete the getMonthlyPrice function. It accepts a tier (string) as input and returns the monthly price for that tier in pennies.

Here are the prices in dollars:

  • "basic" - $100.00
  • "premium" - $150.00
  • "enterprise" - $500.00

Convert the prices from dollars to pennies. If the given tier doesn't match any of the above, return 0 pennies.

To avoid pesky floating-point errors, we often store prices in the currency's base unit. In this case, we are storing the prices in pennies, and a dollar consists of 100 pennies.