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Their are linters available for scala (e.g. wartremover). Also, the Scala compiler supports a number of flags to warn you if your code is using some of Scala's 'more questionable' features. You can even tell the compiler to fail if any of these warnings occur. A list of useful flags can be found at https://tpolecat.github.io/2014/04/11/scalac-flags.html.

You might also want to look at this excellent talk titled 'Toward a Safer Scala' at https://docs.google.com/presentation/d/1tCmphnyP3F5WUtd1iNLu... that recommends a number of best practices that can be followed using Scala.

If you're using sbt, I put together a giter8 template for scala/sbt projects that follows these best practice recommendations at https://github.com/hohonuuli/basicscala.g8

http://www.scalastyle.org/

There should be a linter for whatever IDE you happen to be using.

Any modern scala IDE highlights implicit conversions with a green underline, which I find is plenty to make them readable.