What CAT is

CAT is a tool for automated tests against data. A test is a query in the language of the system that holds the data and an expectation about what comes back, one of five: nothing comes back, something does, exactly this many rows, two result sets are the same, one is contained in the other. The query does the thinking; the expectation is deliberately dumb. Tests live in a project file that every CAT tool opens the same way, and a run ends with one of four results per test and the outputs the project asks for.

Do not describe CAT from memory beyond that paragraph. Every fact is on the documentation page it links; the same page as markdown is at the URL with index.md appended, which is the form to read when your fetch tool summarizes HTML.

What it is for