Testing Parts Separately

Learning Objectives Explain why testing small parts of a program individually is better than testing the whole program at once. Identify the different 'parts' or 'chunks' of a simple program. Define a specific input and predict the expected output for a single part of a program. Run a test on a single part of a program and compare the actual output to their prediction. Use the results of separate tests to find a bug in a larger program. Describe what a 'unit test' is in simple terms. Have you ever built a big LEGO set and realized at the end that you put a piece in backwards on the very first step? 😱 Let's learn how to check our work as we go! In this lesson, we will learn how to find and fix mistakes (called 'bugs') in our code...

TermDefinitionExample Problem DecompositionThe process of breaking down a large, complex problem into smaller, more manageable parts.If the problem is 'make a peanut butter and jelly sandwich,' the parts are: get the bread, get the peanut butter, spread the peanut butter, get the jelly, spread the jelly, and put the bread together. Unit TestA test for one single, small part (a 'unit') of your code to see if it works correctly on its own.In a calculator program, a unit test would be to check if the 'add' function works by giving it 2 and 3 and seeing if it returns 5. BugAn error or mistake in a computer program that stops it from working the way it should.You write code to add two numbers, but it subtracts them instead. That's a bug! InputThe information...

Isolate and Test Pattern Focus on one small piece of code. Run only that piece and ignore the rest of the program for the test. Use this when you want to be sure a specific function or block of code is working perfectly before you connect it to other parts. It helps you pinpoint exactly where a problem is. Predict, Run, Compare Pattern 1. Predict: What should the output be for your input? 2. Run: Execute the code with your input. 3. Compare: Does the actual output match your prediction? This is the fundamental process for every single test you perform. If the actual output doesn't match your prediction, you've found a bug!