For anyone who uses https://moodle.org/plugins/qtype_pmatch, I just wanted to say that I put out a new version today to add one new feature.
Now, when you preview a question, you see a little "Test this question" link in the top right of the question. If you click that you get to a page where you can upload a .csv file of responses (like the attached), and it will compared the expected grades in the .csv file with the grades that you question currently give those responses. Here is what it looks like:
I must say that this is a tiny fraction of the question testing tool I would like to build, but someone was about to create a lot of pmatch questions, so I quicky through this together so that at least they had something.
This should make it a lot easier to create pattern-match questions while having some confidence that they grade teh students the way you want.