Software Testing and Debugging Essentials

Course Goals and Importance of Testing/Debugging

• Course developed due to student lack of testing/debugging skills, a now-essential skill
• Goals include equipping students to test and debug code, prepare them for industry QA roles
• Industry input: new graduates lack software testing lifecycle and tool knowledge; QA is a common entry point for new grads, co-ops

Software Testing and Its Importance

• Software is highly complex and getting it right is difficult, requiring careful consideration to avoid errors
• Software testing verifies software functionality and performance meets requirements
• Testing was often neglected initially, but became critical due to software's increasing complexity and user expectations

Debugging Process

• Debugging involves finding and fixing software problems
• Locating the bug source is often the most time-consuming part analogous to detective work, requiring gathering clues and evidence (inserting print statements and using debuggers)

Testing Implications

• Testing confirms test correctness but not software correctness; bugs might remain undiscovered
• Bug discovery decreases over time and is not linear, leading to diminishing returns for testing. Testing often stops before fully eliminating all bugs
• Software rarely achieves perfect correctness due to its inherent complexities; proven correctness exists only for the simplest applications
• Users often don't encounter and reveal bugs because they're not extensively testing the software. Most applications ship with many known bugs that developers don't fix.

Testing vs. Debugging

• Testing verifies software correctness by comparing actual results to expected results; debugging finds and fixes problems in buggy code
• Different teams often handle testing and debugging
• In smaller companies, developers might perform both - both roles are different and should not be confused.