How large is too large and what counts as prohibitive? We're using lints with types on over a million lines of TypeScript and the lints are instant inside of the editors. They take a good 10 minutes to run in CI across the whole project, but that's shorter than the tests which are running in parallel.
Good point, I was talking about similarly sized code bases, yes.
Because of the hefty CI runtime increase, myself I opposed to adding it. We have lots of parallel branches that people work on and many code reviews every day, where the CI just needs to run from a clean slate so to speak.
But most of the current long CI run penalty in the frontend of that comes from tsc, not ESLint, in my case.
I might look into it again.
In the project there already are all kinds of optimizations (caching to speed up full Ci runs with common isolated parts of a monorepo).
And for TS, project references + incremental builds for development are used, tsc in a monorepo would be miserable without them.
I think it depends on your code and dependencies. At work, the time between making a change in our codebase (which is much smaller than a million LOC) to having ESLint update itself in the IDE can take 5+ seconds, depending on what you changed. But we also use some pretty over-engineered, generic-heavy dependencies across our entire codebase.
