Why do software testers prefer dark mode?

When testing connections to Large Language Models, I often ask them to tell me a joke. 

Recently, GPT-4o-mini offered this:

"Why do software testers prefer dark mode?
Because light attracts bugs!"

It's a light joke, but it highlights a common misconception that software testers don't want to find bugs. This reminds me of Glenford Myers' critique in his 1976 book Software Reliability:

“One usually encounters a definition such as,
‘Testing is the process of confirming that a program is correct.
It is the demonstration that errors are not present.’

The main trouble with this definition is that it is totally wrong;
in fact, it almost defines the antonym of testing.”

DEMONSTRATING that software can work under specific conditions is part of testing -- but it is just the start. 

Modern software development thrives on automated DEMONSTRATIONS. They help confirm what we believe to be true and detect regressions quickly. But if we stop at DEMONSTRATION, we miss the chance of DISCOVERING bugs that will bug people we care about. 

Testing isn't just about DEMONSTRATING that software can work -- it's about DISCOVERING how it may not work as desired. 

• Test to DISCOVER what is undocumented. 
• Test to DISCOVER what is unsafe. 
• Test to DISCOVER what is unintended. 
• Test to DISCOVER what is unpredictable. 
• Test to DISCOVER what is unknown. 

If you aren't seeking to DISCOVER , you may not be testing.

Don't test in dark mode. 

Shine a light to attract the bugs before they attract your stakeholders' ire.