Read it before you ship it

Each of these is a pattern a model produces on request, in the form it arrives: one line, a stated purpose, no test inputs. They all work on the example they were asked about. Your job is to find the input that shows what else they do.

Your answer is an input, and it is checked by running it. Nothing here takes your word for it.

Patterns

What it was asked to do

Check that a string is a valid email address.

The single most copied regular expression there is, in one of its shorter forms.

^[\w.]+@[\w]+\.[a-z]{2,3}$

^[\w.]+@[\w]+\.[a-z]{2,3}$

^+@+\.{2,3}$

Find the input it accepts and should not

Give an input that this pattern matches and, given what it was asked to do, should not. It will be run against the pattern.

Your input