Getting field name as string - scala

Question

I have a trait that overrides toString to print the values of all fields:
/**
* Interface for classes that provide application configuration.
*/
trait Configuration {
/** abstract fields defined here. e.g., **/
def dbUrl: String
/**
* Returns a list of fields to be excluded by [[toString]]
*/
protected def toStringExclude: Seq[String]
/**
* Returns a String representation of this object that prints the values for all configuration fields.
*/
override def toString: String = {
val builder = new StringBuilder
val fields = this.getClass.getDeclaredFields
for (f <- fields) {
if (!toStringExclude.contains(f.getName)) {
f.setAccessible(true)
builder.append(s"${f.getName}: ${f.get(this)}\n")
}
}
builder.toString.stripSuffix("\n")
}
}
A concrete class currently looks like this:
class BasicConfiguration extends Configuration {
private val config = ConfigFactory.load
override val dbUrl: String = config.getString("app.dbUrl")
/**
* #inheritdoc
*/
override protected def toStringExclude: Seq[String] = Seq("config")
}
The problem is, if config were renamed at some point, the IDE would miss "config" in toStringExclude as it's just a string. So I'm trying to find a way to get the name of a field as a string, like getFieldName(config).

Answer 1

Using https://github.com/dwickern/scala-nameof,
import com.github.dwickern.macros.NameOf._
class BasicConfiguration extends Configuration {
private val config = ConfigFactory.load
override val dbUrl: String = config.getString("app.dbUrl")
/**
* #inheritdoc
*/
override protected def toStringExclude: Seq[String] = Seq(nameOf(config))
}

Answer 2

I don't like this and I wouldn't do this but here's this:
class BasicConfiguration extends Configuration {
private val config = ConfigFactory.load
override val dbUrl: String = config.getString("app.dbUrl")
private val excludeFields: Set[Any] = Set(config)
override protected val toStringExclude: Seq[String] = {
this.getClass
.getDeclaredFields
.filter(field => Try(field.get(this)).fold(_ => false, a => excludeFields.contains(a)))
.map(_.getName)
.toList
}
}