Test-Case Reducers: Underappreciated Debugging Tools and Their Creative Uses

Test-case reducers are less well known than they should be, and those who are aware of them don't always realise the variety of ways we can use – perhaps even abuse! – them.

I'll start at the basics, because the idea is so simple that it can be hard to believe it works.

Test-case reducers try to reduce the length of an input, but we can force them to take into account additional factors such as how often an error occurs, or the number of instructions.