Lab 5: Test-Driven Development

Introduction

This lab practices the skills needed for Test Driven Development. When developing software, it is important to test features as you build them. This helps ensure the functionality of your code and prevents bugs from cascading into other parts of your application. To do this, we will utilize the Test Driven Development (TDD) approach, which is a software development process that relies on the repetition of a short cycle:

• Write a test for an unimplemented feature
• Run all tests and check that the new test fails
• Write the feature
• Run all tests and check that the new test passes
• Refactor the code

The TDD process will be used throughout this lab. The goal for this lab is to help you better understand your code before you even write it. This practice can help you write better code and prevent bugs from occurring in the future.

Task 1: Fail the Item Tests

• Open the itemTests.py file.
• Examine the unimplemented test functions test_calculate_item_total_price_converts_discount and test_calculate_item_total_price_correct.
• Complete TODO 1 inside the test_calculate_item_total_price_converts_discount function by writing a test that follows all listed requirements in the comments.
• Complete TODO 2 inside the test_calculate_item_total_price_correct function by writing a test that follows all listed requirements in the comments.
• Run the test.py file and examine the output reports, which are located in the reports folder and are named by the current date and number of times the testing suite has been run today.

Task 2: Item Class Implementations

• Open the invoice.py file.
• Complete TODO 3 inside the calculate_item_total_price method so that it calculates the price of an item based on the quantity, unit price, and discount.
• Run the test.py file and examine the latest output reports. Make sure you are now passing all Item tests.

Task 3: Fail the Invoice Tests

• Open the invoiceTests.py file.
• Examine the unimplemented test functions test_invoice_add_item_appends_item and test_invoice_add_item_checks_discounted.
• Complete TODO 4 inside the test_invoice_add_item_appends_item function by writing a test that follows all listed requirements in the comments.
• Complete TODO 5 inside the test_invoice_add_item_checks_discounted function by writing a test that follows all listed requirements in the comments.
• Run the test.py file and examine the latest output reports. You should be failing the Invoice tests.

Task 4: Invoice Class Implementations

• Open the invoice.py file.
• Complete TODO 6 inside the add_item method so that it appends an item to the invoice.
• Run the test.py file and examine the latest output reports. Make sure you are now passing all Invoice tests.

Submission Details

• On Canvas, submit the following:
  • A zip file of the entire lab5 directory, renamed as your NinerNetID.zip (e.g., dgary9.zip)
    • TIP: If you are struggling to remember how to zip your submission, here's an example of how to do it from the terminal on Mac or Linux machines: zip -r -X dgary9.zip .
    • TIP: For Windows users who want to use their terminal to zip their submission, you can use the 7za command. Here's an example of how to do it: 7za dgary9.zip .
    • NOTE: In the above examples, dgary9 is the NinerNetID of the student submitting the assignment and . is the directory that contains the files to be zipped, which is the current directory (lab5) in this case.