Defensive Programming - DevCon 2023

Not all bugs are created equal. Avoid the expensive ones by making more of the ones that are easy to find and fix.

Every programming language has its own syntactical quirks. The C family loves braces. Python loves indentation. BASIC loves words. And Perl loves #%@!{}]&.

Compile errors are easy to keep out of deployed code (just remember to Debug > Compile). Which is good because they hard crash Access in Runtime mode.

Your client knows what’s wrong. They *think* they know how to fix it. But treating symptoms is never as effective as treating the disease.

You can have a bug in your code and/or in your test. You’re unlikely to have the *same* bug in your code and your test.

It’s impossible to predict every possible scenario that could befall our applications in the wild. But we need to at least try.

As you install the final piece of crown molding in the dog’s second bedroom, you can’t help but smile at the absurdity of it all.

The logic error is the most dangerous and insidious of all software errors.

Compile errors are cheaper and easier to fix than runtime errors. Here are five ways to turn potential runtime errors into compile errors.

Runtime errors are cheaper and easier to fix than logic errors. Here are five ways to make that happen.

Identify the critical functions in your application. Then, apply one or more of these techniques to ensure that if they break, someone will notice.

The immediate negative feedback loop that syntax errors provide is a powerful learning tool.

Increase the quality of your existing data by running it through a series of validity checks and showing your users the results.

Let’s apply the concept of frictionless development to the defensive programming technique of data validity checks.

Software Developers Can Almost Eliminate Logic Errors With This Powerful Technique

This simple technique is a foolproof way to avoid the sort of logic bug that can live undetected in your codebase for years.

Don’t build digital Maginot Lines. Program your defenses in depth.

The fewer items you need to mentally track the less likely you are to make mistakes or generate bugs.

Doc tests are not a replacement for unit or integration testing. But they do provide the best return on investment (ROI) of any type of test, mostly because the effort to write them is near zero.