How can I have a build step depend on the contents of a directory?

[fierce cedar]

I have some resources to embed. I need to preprocess some of them. I'd like to drive that through the build. But I don't want to call out every source file in the build script. The rule I'm looking for would be something like "any changes under this folder invalidate this artifact"

[clear heart]

unfortunately cant do that yet, but you can usually make a step re-trigger each time
So if its not too expensive, you can do that (usually done by setting the step to have side effects, but it depends on the concrete step implementation, there's no generic way to do that AFAIK)

[fierce cedar]

ok, thanks. it sounds like I'm not the first to ask 🙂

I saw the side effect workaround. I guess I can scan the directory at build time and add them all to the graph? does that sound expensive to you?

if I did that, will the build cache everything? or does it work on hashes/modstamps?

[clear heart]

I don't think that would be expensive, its definitely an option
If you don't plan on adding files maybe it'd make sense to just hardcode the paths though
I'm honestly not sure if it'd be cached or if it'd reiterate the dir each time