https://news.ycombinator.com/item?id=45425568 303 points, 3 days ago, 47 comments.

Great topic. But imo Too Soon (to post again).

I thought hackernews didn't even allow same links within 7 days.

> Test code doesn’t have its own test code

I would love it if we had better tools to make testing the tests explicit, line inline "This is what this code shouldn't do and it's a problem if there's no test that could catch it if it does" blocks.

When I do functional unit tests, they tend to include the same functional logic as the code to test. What I strive for is then to express it in a different and possibly clearer way, and I see the testing as mutual testing of two implementations, one more easily humanly checkable.

I have always wanted to deploy mutatation testing and experimented with it back in the .Net framework days with a package called NinjaTurtles.

https://stryker-mutator.io/docs/

Rust has a tool for mutation testing called cargo-mutants iirc. It's not perfect but it'll find low-hanging fruit