How to avoid the need to import custom ProductHint on loading config

Hi, I am consistently using camelCase for config keys, and I use a single entry point to read config from, used in multiple places (tests etc) (provided bellow). I currently need to consistently import a camelCase product hint in every place that uses that method (or loadConfig directly for that matter). Config parser method:

import pureconfig.{ConfigConvert, loadConfig}

object Parser {
  def parse[T](conf: Config)(implicit convert: ConfigConvert[T]): T = {
    val loaded = loadConfig[T](conf)(convert)
    loaded.left.foreach(_.toList.map(_.toString).foreach(f => logError(f)))
    loaded.right.get
  }
  import pureconfig.{ProductHint, CamelCase, ConfigFieldMapping}
  implicit def camelCaseHint[T]: ProductHint[T] = ProductHint[T](ConfigFieldMapping(CamelCase, CamelCase))
}

You can see I tried a few naive things around trying to avoid having ProductHint imported in the scope of the method.

Usage:

import Parser.camelCaseHint //Will look for kebab-case keys without this!
val fromConfig = Parser.parse[MyConfigClass](config)

Picking up an implicit value that is not explicitly included in the list of implicit parameters of the function (loadConfig in this case, or even my parse function) is quite dark magic to me. In fact, I didn’t know Scala allowed this! And I had a look at the classic SO question on this.

How would you approach this?

I can guess this goes down to the fact that the ProductHint companion object defines a default implicit instead of having this imported explicitly (e.g. by import pureconfig._)

[ruippeixotog]

Closing this due to inactivity and because it’s more of a design decision than a bug/issue.

[eneveu]

In our project, we use a trait to import the implicit ProductHint:

trait ConfigSupport {
  implicit def hint[T]: ProductHint[T] = ProductHint[T](ConfigFieldMapping(CamelCase, CamelCase))
}

And we use it like this:

object XxxAppConfig extends ConfigSupport {
  def loadConfigOrThrow(config: Config = ConfigFactory.load()): XxxAppConfig = {
    pureconfig.loadConfigOrThrow[XxxAppConfig](config, "some.namespace")
  }
}