Is it possible to set a custom type name for a lens, to show up in the `LensFailure`? I tried this: ...

# http4k

[Mikael Ståldal]

Is it possible to set a custom type name for a lens, to show up in the LensFailure? I tried this:

Path.mapWithNewMeta(regex("([0-9a-fA-F])", 1), ParamMeta("Hex encoded")).of("myHexParam")

But it does not compile:

Kotlin: Cannot access '<init>': it is protected in 'ParamMeta'

[dave]

ah - maybe not then!

[dave]

Also that is an illegal value for the param meta. You could only choose one of the other valid cases anyway because otherwise the spec would be broken

[Mikael Ståldal]

Without this, the error become:

path 'myHexParam' must be string

which is not so helpful.

[dave]

well, that's because it's piggybacking on the top of the entire lens system 🤷

[Mikael Ståldal]

You mean the OpenAPI spec? I am not using contracts now, only standard routes.

[Mikael Ståldal]

And ServerFilters.CatchLensFailure

[dave]

No. All of the lenses are piggybacking on the same infrastructure, which leads to the not-amazing-but-actually-unavoidable message 🙂

[Mikael Ståldal]

Another option would be to have the error message like this:

path 'myHexParam' must be string with pattern '[0-9a-fA-F]'

[dave]

yes, if we rewrote the entire system that would be possible,

[James Richardson]

Can values4k with validation help here?

[dave]

not really. The problem isn't the validation - that works. it's documenting the path parameters in the openapi spec

[James Richardson]

OK, maybe I misunderstood, I thought it was about getting more info out of a LensFailureException.

[Mikael Ståldal]

It is about getting better error messages.