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by dependency_2x 143 days ago
Ratchet is a good name/pattern. It is also grandfathering.

It is similar to how code coverage can be done. Old coverage may be low e.g. 40%, but may require 80% coverage on new lines, and over time coverage goes up.

I wonder if there has ever been a sneaky situation where someone wanted to use forbiddenFunction() really bad, so they remove the call elsewhere and tidy that up, so they could start using it.
2 comments
zdc1 143 days ago
Yep. Grandfathering, deprecation. It's a new implementation of the same concepts.

And ditto for test coverage quality gates. I've seen that pattern used to get a frontend codebase from 5% coverage to >80%. It was just a cycle of Refactor -> Raise minimum coverage requirement -> Refactor again -> Ratchet again, with the coverage gate used to stop new work from bringing down the average.

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antonyh 143 days ago
One would hope code reviews could pick up these deceptions, but then again they would spot the use of forbidden functions too albeit much later in the dev cycle than is optimal. Breaking the build early is a solid idea, before it's even committed to source control. No different to applying PMD, CPD, Checkstyle, eslint, yamllint, other linters, but with a custom rule. I really want to use this pattern, there's semi-deprecated code in so many codebases.

For more control and to close that loophole, it could be possible to put annotations/comments in the code to `/* ignore this line */` in the same way that eslint does? Or have a config that lists how many uses in each file, instead of one-per-project?? There's always refinements, but I'm sure that for many projects the simplicity of one counter is more than enough, unless you have devious developers.

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jitl 143 days ago
if you have eslint you might as well just write custom rules and get actual syntax aware linting rather than relying on more brittle regex rules. claude et al are very good at getting a lint rule started, with a bit of setup you can make testing lint rules easy. we have a zillion custom rules at notion, most are pretty targeted “forbid deprecated method X besides circumstance Y” kind of things
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