RegEx using greedy qualifier for N times is quoted incorrectly

[ruir6o]

implementation 'org.http4k:http4k-core:4.17.0.0'
implementation 'org.jetbrains.kotlin:kotlin-stdlib:1.6.0'

---

I have just found out about http4k and I decided to create a simple service with it. My very first attempt at getting a path parameter to be validated against a UUID RegEx is failing however. This is how I've defined the RegEx:

const val COMPACT_UUID_REGEX = "[a-fA-F0-9]{32}"
const val PRETTY_UUID_REGEX = "[a-fA-F0-9]{8}-[a-fA-F0-9]{4}-[a-fA-F0-9]{4}-[a-fA-F0-9]{4}-[a-fA-F0-9]{12}"
const val UUID_REGEX = "(?:${COMPACT_UUID_REGEX}|${PRETTY_UUID_REGEX})"

And it is put in a router by using

routes(
    "api/v1/sample/{id:$UUID_REGEX}" bind POST to { /* ... */}
)

However running the application yields:

Exception in thread "main" java.util.regex.PatternSyntaxException: Unclosed counted closure near index 35
\Qapi/v1/sample/\E((?:[a-fA-F0-9]{32)\Q|[a-fA-F0-9]\E([^/]+)\Q-[a-fA-F0-9]\E([^/]+)\Q-[a-fA-F0-9]\E([^/]+)\Q-[a-fA-F0-9]\E([^/]+)\Q-[a-fA-F0-9]\E([^/]+)\Q)}\E

Looking at the exception it seems like http4k is replacing the { and } in an attempt to quote literal path segments, however it is applying it to the regex section as well, interfering with the greedy qualifiers defined in the UUID RegEx.

[daviddenton]

Thanks for the report. It looks like a tricky one to solve TBH (Regexes 🙄 ). I've added a failing test anyway here

[ruir6o]

@daviddenton I think a simple custom parser could do the trick. I've created a simple PR (#678) to showcase this.

[Angel-Ponce]

Same problem, there are some solution to fix it?