Python Testing

What is Software Testing?

Three Common Definitions:

Definition 1: "Testing is a process of demonstrating that errors are not present"

• ❌ Problem: Testing can only show presence of bugs, not absence
• Famous Dijkstra quote: "Testing shows the presence of bugs, not the absence"

Definition 2: "Testing is to show that a program performs its intended function correctly"

• ❌ Problem: May subconsciously write tests that avoid finding errors
• ❌ Problem: Doesn't test what program is NOT supposed to do

Definition 3: "Testing is the process of establishing confidence that a program does what it is supposed to do"

• ❌ Problem: What if program also does what it's NOT supposed to do?

The CORRECT Definition:

"Testing is the process of executing a program with the intent of finding errors"

Key mindset shift:

• The more errors you find, the better the testing
• Write tests with the intention to find bugs
• Think like an adversary: battle between tester and developer

The Triangle Function Exercise

Specification: